Week 1 SAQs PDF

Lecture 1: 1. Is the vertebral centrum dorsal or ventral? The vertebral centrum is ventral, as it forms the anterior body of the vertebra and lies in front of the neural arch. 2. Is the notochord pre-axial or post-axial? The notochord is pre-axial, serving as the central scaffold for the developmen...

Lecture 1: 1. Is the vertebral centrum dorsal or ventral? The vertebral centrum is ventral, as it forms the anterior body of the vertebra and lies in front of the neural arch. 2. Is the notochord pre-axial or post-axial? The notochord is pre-axial, serving as the central scaffold for the development of the vertebral column. 3. Name the ossification centres involved in vertebral development. - Centrum: Forms the central portion of the vertebral body. - Neural arch elements: Form the dorsal aspect of the vertebral column, surrounding the spinal cord. - Costal elements: Develop into ribs in the thoracic region or transverse processes in other regions. 4. Which nerve supplies intervertebral muscles? The mixed spinal nerve supplies intervertebral muscles, exiting the vertebral canal through intervertebral foramina at the level of the intervertebral discs. 5. A lesion to which spinal nerve would produce scoliosis due to hemivertebrae? Describe the clinical presentation. Lesions of a segmental spinal nerve near a hemivertebra may cause scoliosis, presenting with an asymmetric curvature of the vertebral column. 6. Aside from generic trauma, what is a common injury mechanism leading to nerve root compression at intervertebral foramina? A common mechanism is failure of vertebral segmentation, such as in block vertebrae, leading to reduced foraminal space and nerve root compression. 7. Name a common action of the erector spinae and interspinales muscles. Both the erector spinae and interspinales muscles contribute to extension of the vertebral column. 8. Which segment of the vertebral column contributes to thoracic rib development? The thoracic vertebrae, derived from somites at corresponding levels, contribute to rib formation through their costal elements. 9. Through which space does a spinal nerve exit the vertebral column? Spinal nerves exit through the intervertebral foramina, formed by the superior and inferior notches of adjacent vertebrae. 10. What are the boundaries and contents of the intervertebral foramina? - Boundaries: - Superior: Pedicle of the vertebra above. - Inferior: Pedicle of the vertebra below. - Anterior: Intervertebral disc and vertebral bodies. - Posterior: Zygapophyseal joints. - Contents: Spinal nerve roots, dorsal root ganglia, and accompanying blood vessels. 11. Name a sagittal plane movement of the lumbar vertebrae. Flexion and extension occur in the sagittal plane at lumbar vertebrae. 12. What is the bilateral action of the multifidus muscle? The multifidus performs extension of the vertebral column when contracting bilaterally. 13. What is the most distal joint affected by vertebral body movement? The sacroiliac joint is the most distal joint influenced by vertebral body movements. 14. Which joint in the vertebral column performs no action on rotation? The lumbar zygapophyseal joints restrict rotational movements due to their orientation. 15. Which movement can the anterior longitudinal ligament restrict in the vertebral column? The anterior longitudinal ligament restricts hyperextension of the vertebral column. 16. Which muscles are most likely to face active/passive insufficiency during hyperextension of the vertebral column? The erector spinae muscles may face insufficiency during extreme hyperextension of the vertebral column. 17. Which muscles attach at the spinous processes of vertebrae? - Rhomboid minor. - Trapezius (lower fibres). - Latissimus dorsi. 18. Movements in which planes are permissible at cervical vertebrae? - Sagittal plane: Flexion and extension. - Transverse plane: Rotation. - Frontal plane: Lateral flexion. 19. What type of contraction does the erector spinae perform during trunk flexion? The erector spinae performs eccentric contraction to control the descent during trunk flexion. 20. How many somites contribute to the formation of a single vertebra? Two adjacent somites contribute to the formation of a single vertebra through the process of re- segmentation. 21. Which vertebral region is characterised by transverse foramina? The cervical vertebral region is identified by the presence of transverse foramina. 22. From which mesodermal component is the vertebral body derived? The vertebral body is derived from the sclerotome, part of the paraxial mesoderm. 23. Which congenital malformation results from too few notochordal cells remaining during vertebral development? Block vertebrae occur when insufficient notochordal cells remain, leading to fused vertebrae. 24. Which vertebral anomaly results from failure of lateral ossification centres? Butterfly vertebrae result from failure of lateral ossification centres to fully form and fuse. 1. Is the vertebral centrum dorsal or ventral? The vertebral centrum is ventral, forming the anterior body of the vertebra. 2. Is the neural arch dorsal or ventral? The neural arch is dorsal, surrounding the spinal cord posteriorly. 3. Is the notochord pre-axial or post-axial? The notochord is pre-axial, acting as the central scaffold for vertebral development. 4. Is the intervertebral disc pre-axial or post-axial? The intervertebral disc is pre-axial, forming anterior to the neural arch. 5. Describe the vertebral centrum. The vertebral centrum is the bony structure forming the main weight-bearing body of the vertebra. 6. Describe the neural arch. The neural arch is the posterior structure enclosing the vertebral foramen and supporting the processes. 7. Describe the notochord. The notochord is the embryonic structure that becomes the nucleus pulposus of the intervertebral discs. 8. Describe the intervertebral disc. The intervertebral disc is the fibrocartilaginous joint between vertebral bodies, providing flexibility and cushioning. 9. Which nerve supplies the intervertebral muscles? The dorsal rami of mixed spinal nerves supply the intervertebral muscles. 10. Which nerve supplies the epaxial muscles in vertebral development? The dorsal rami of spinal nerves supply the epaxial muscles. 11. A lesion to which nerve would produce the observed clinical sign involving the vertebral centrum? Describe the positioning at joints. A lesion to the spinal nerve root compressing the centrum may impair sensory and motor function at the affected vertebral level. 12. A lesion to which nerve would produce the observed clinical sign involving the neural arch? Describe the positioning at joints. A lesion to the dorsal ramus may impair motor function and stability of the neural arch. 13. Aside from generic trauma, what is a common injury mechanism for lesions to the intervertebral disc? Repetitive axial loading or improper lifting can lead to disc herniation. 14. Aside from generic trauma, what is a common injury mechanism for lesions to the notochord? Incomplete resorption of the notochord can result in chordoma, a rare tumour. 15. Name a common action of the intervertebral muscles and the multifidus. Both stabilise the vertebral column and resist excessive movement. 16. Name a common action of the epaxial muscles and the erector spinae. Both extend the vertebral column. 17. Which segment of the paraxial mesoderm contributes to the vertebral body? The sclerotome contributes to the vertebral body. 18. Which segment of the paraxial mesoderm contributes to the neural arch? The sclerotome contributes to the neural arch. 19. Which space does the notochord occupy during vertebral development? The notochord occupies the midline of the mesenchyme that forms the vertebral column. 20. Which space does the intervertebral disc occupy during vertebral development? The intervertebral disc occupies the space between adjacent vertebral bodies. 21. What are the boundaries/contents of the vertebral foramen? Boundaries: Vertebral body, pedicles, and laminae. Contents: Spinal cord, meninges, and spinal nerves. 22. What are the boundaries/contents of the intervertebral foramen? Boundaries: Superior and inferior vertebral notches, zygapophyseal joints, and intervertebral discs. Contents: Spinal nerves and dorsal root ganglia. 23. Name a sagittal plane movement of the vertebral column during development. Flexion of the vertebral column. 24. Name a sagittal plane movement of the intervertebral disc. Compression and extension of the intervertebral disc. 25. What is the unilateral action of the intervertebral muscles? Lateral flexion of the vertebral column. 26. What is the bilateral action of the epaxial muscles? Extension of the vertebral column. 27. What is the most distal joint the vertebral centrum acts on? The sacroiliac joint. 28. What is the most distal joint the intervertebral disc acts on? The sacroiliac joint. 29. Which joint of a vertebra does the intervertebral disc perform no action on? The intervertebral disc does not act on the atlanto-occipital joint. 30. Which joint of a vertebra does the vertebral centrum perform no action on? The vertebral centrum does not act on the atlanto-occipital joint. 31. Which movement can the anterior longitudinal ligament prevent/restrict/control? The anterior longitudinal ligament prevents hyperextension of the vertebral column. 32. Which movement can the posterior longitudinal ligament prevent/restrict/control? The posterior longitudinal ligament prevents hyperflexion of the vertebral column. 33. Which of the pinned muscles is most likely to be challenged by active/passive insufficiency during vertebral flexion? The erector spinae muscles are most likely to be challenged. 34. Which of the pinned ligaments is most likely to be challenged by active/passive insufficiency during vertebral extension? The anterior longitudinal ligament is most likely to be challenged. 35. Which muscles attach at the spinous processes of the developing vertebrae? The multifidus, spinalis, and interspinales attach at the spinous processes. 36. Which muscles attach at the transverse processes of the developing vertebrae? The levator costarum, intertransversarii, and longissimus attach at the transverse processes. 37. Movements in which cardinal planes are permissible at developing vertebral joints? Sagittal: Flexion and extension. Frontal: Lateral flexion. Transverse: Rotation. 38. What movement occurs through the sagittal plane at the vertebral column during flexion? Flexion occurs, reducing the angle between adjacent vertebrae. 39. What type of muscle contraction does the multifidus perform during extension of the vertebral column? The multifidus performs concentric contraction during extension. 40. How many vertebral segments does the vertebral centrum develop from? The vertebral centrum develops from two adjacent somites. 41. How many vertebral segments does the intervertebral disc develop from? The intervertebral disc develops from two adjacent somites. 42. Which vertebral region is the vertebral centrum most affected by growth abnormalities? The thoracic region is most affected by growth abnormalities. 43. Which vertebral region is the intervertebral disc most prone to degeneration? The lumbar region is most prone to degeneration. 44. Which vertebral element is the neural arch derived from? The neural arch is derived from the sclerotome. 45. Which vertebral element is the centrum derived from? The centrum is derived from the sclerotome. 46. Which movements are favoured/NOT possible between vertebrae during early development? Favoured: Flexion and extension. NOT possible: Significant rotation due to underdeveloped facet joints. 1. What is the role of the notochord in vertebral development? The notochord signals the surrounding mesoderm to form the vertebral column and becomes the nucleus pulposus of intervertebral discs. 2. Describe the process of vertebral segmentation and re-segmentation. Vertebrae form from two adjacent somites through re-segmentation, aligning with intervertebral discs and spinal nerve roots. 3. What is the function of the perinotochordal sheath during vertebral development? It provides structural support and guides the formation of the vertebral bodies. 4. What are the three stages of vertebral development? Mesenchymatous (cell migration), cartilaginous (formation of hyaline cartilage), and osseous (ossification of primary centres). 5. How do vertebral anomalies like hemivertebrae occur? They result from failure of one cartilage centre to develop, leading to vertebral asymmetry and potential scoliosis. 6. What is the role of sclerotome cells in vertebral development? Sclerotome cells migrate to form the vertebral bodies, neural arches, and costal elements. 7. Which regions of the mesoderm contribute to vertebral development? The paraxial mesoderm forms somites, which contribute to vertebrae, ribs, and muscles. 8. What are the primary ossification centres of a vertebra? Centrum (unpaired), neural arches (paired), and costal elements (variable fusion or rib formation). 9. What role do blood vessels play in vertebral segmentation? Blood vessels from the aorta form between somites, driving segmentation by providing nourishment to developing vertebrae. 10. What structural changes occur during the cartilaginous stage of development? Hyaline cartilage replaces mesenchyme, forming the annulus fibrosus and nucleus pulposus in intervertebral discs. 11. What is block vertebra, and how does it form? Block vertebra occurs when segmentation fails, leading to fused vertebrae with obliterated intervertebral discs. 12. What developmental process results in butterfly vertebrae? Failure of ossification of lateral cartilage centres results in butterfly vertebrae with a split vertebral body. 13. How do costal elements differ in the thoracic and lumbar regions? In the thoracic region, costal elements form ribs, while in the lumbar region, they contribute to transverse processes. 14. What is the significance of interlaminar and neurocentral cartilage in vertebral growth? They allow vertebral growth during childhood and fuse around 6–8 years of age. 15. How do vertebral elements vary between cervical, thoracic, and lumbar regions? Cervical: Transverse foramina and bifid processes. Thoracic: Rib facets. Lumbar: Large vertebral bodies and interlocking facets. 16. What are the clinical implications of reduced notochordal cells during development? Reduced notochordal cells lead to poor nucleus pulposus development, contributing to disc degeneration and block vertebrae. 17. What is the role of the annulus fibrosus and nucleus pulposus in intervertebral discs? The annulus fibrosus provides tensile strength, while the nucleus pulposus absorbs compressive forces. 18. Why are intervertebral discs thinner in adults compared to infants? Water content decreases with age, reducing disc height and elasticity. 19. What is the relationship between vertebral growth plates and secondary ossification centres? Growth plates remain active until early adulthood, and secondary ossification centres form processes like spinous and transverse processes. 20. How do Hox genes regulate vertebral region differentiation? Hox genes control the expression of region-specific features, such as ribs in thoracic vertebrae and transverse foramina in cervical vertebrae. Lecture 2 1. Is the cervical vertebra dorsal or ventral? The cervical vertebra, like all vertebrae, has both dorsal and ventral components, but the ventral aspect refers to the vertebral body, while the dorsal aspect includes the neural arch and processes. 2. Is the thoracic vertebra pre-axial or post-axial? The thoracic vertebra is considered post-axial, as it is located posterior to the embryonic notochord. 3. Name the features of the lumbar vertebra. The lumbar vertebrae have large kidney-shaped vertebral bodies, short spinous processes, and articular facets oriented medially and laterally to allow flexion and extension. 4. Which nerve supplies the zygapophyseal joints in the cervical region? The cervical zygapophyseal joints are supplied by the medial branches of the dorsal rami of spinal nerves. 5. A lesion to which spinal nerve would produce pain in the thoracic intercostal space? Describe the clinical presentation. A lesion to a thoracic spinal nerve, such as T5, could result in intercostal neuralgia, presenting as radiating pain in the intercostal space corresponding to the nerve's dermatome. 6. Aside from generic trauma, what is a common injury mechanism causing disc herniation in the lumbar region? Repetitive axial loading and improper lifting mechanics often lead to disc herniation in the lumbar region, typically between L4 and L5 or L5 and S1. 7. Name a common action of the multifidus and rotatores muscles in the lumbar region. Both the multifidus and rotatores contribute to stabilisation and rotation of the lumbar vertebral column. 8. Which vertebral element forms the transverse processes in the thoracic region? In the thoracic region, the transverse processes are formed from costal elements that later develop ribs. 9. Through which space does the spinal nerve exit the lumbar vertebral column? The spinal nerves exit through the intervertebral foramina, bounded by adjacent vertebral pedicles and zygapophyseal joints. 10. What are the boundaries and contents of the cervical transverse foramina? Boundaries: Surrounding transverse processes. Contents: Vertebral artery and vein (C6 to C1) and accompanying sympathetic plexus. 11. Name a movement in the sagittal plane allowed at the thoracic vertebral column. Flexion occurs in the sagittal plane of the thoracic vertebral column, though it is limited by rib attachments. 12. What is the bilateral action of the erector spinae muscles in the thoracic region? The erector spinae muscles extend the thoracic vertebral column when acting bilaterally. 13. What is the most distal joint influenced by the sacral vertebrae? The most distal joint influenced by the sacral vertebrae is the sacroiliac joint. 14. Which joint in the thoracic region does not allow rotation? The costovertebral joints restrict rotation in the thoracic region due to rib attachments. 15. Which movement does the anterior longitudinal ligament restrict in the cervical spine? The anterior longitudinal ligament restricts hyperextension in the cervical spine. 16. Which muscles attach to the spinous processes of thoracic vertebrae? The trapezius, rhomboid major, and latissimus dorsi muscles attach to the thoracic spinous processes. 17. Movements in which planes are permissible at the cervical vertebrae? Sagittal: Flexion and extension. Frontal: Lateral flexion. Transverse: Rotation. 18. What type of contraction does the erector spinae perform during forward flexion of the thoracic spine? The erector spinae performs eccentric contraction during forward flexion to control the descent. 19. How many segments does a sacral vertebra originally consist of before fusion? A sacral vertebra originally consists of five segments before fusing into a single sacrum. 20. Which vertebral region is characterised by ribs articulating with transverse processes? The thoracic vertebral region is characterised by rib articulation with the transverse processes. 1. Is the cervical vertebra dorsal or ventral? The cervical vertebra has both dorsal (neural arch) and ventral (vertebral body) components. 2. Is the thoracic vertebra dorsal or ventral? The thoracic vertebra has dorsal (neural arch) and ventral (vertebral body) components. 3. Is the lumbar vertebra dorsal or ventral? The lumbar vertebra has dorsal (neural arch) and ventral (vertebral body) components. 4. Is the sacral vertebra dorsal or ventral? The sacral vertebra has both dorsal (neural arch) and ventral (vertebral body) components. 5. Is the cervical vertebra pre-axial or post-axial? The cervical vertebra is post-axial, posterior to the notochord. 6. Is the thoracic vertebra pre-axial or post-axial? The thoracic vertebra is post-axial, posterior to the notochord. 7. Is the lumbar vertebra pre-axial or post-axial? The lumbar vertebra is post-axial, posterior to the notochord. 8. Is the sacral vertebra pre-axial or post-axial? The sacral vertebra is post-axial, posterior to the notochord. 9. Describe the cervical vertebra. The cervical vertebra has a small, oval body, transverse foramina, and bifid spinous processes. 10. Describe the thoracic vertebra. The thoracic vertebra has a heart-shaped body, costal facets for rib attachment, and long, downward- sloping spinous processes. 11. Describe the lumbar vertebra. The lumbar vertebra has a large, kidney-shaped body, short spinous processes, and interlocking articular facets. 12. Describe the sacral vertebra. The sacral vertebrae are fused to form the sacrum, providing a stable base for the spine and transmitting weight to the pelvis. 13. Which nerve supplies the intertransversarii muscles in the cervical region? The ventral rami of cervical spinal nerves supply the intertransversarii muscles. 14. Which nerve supplies the intertransversarii muscles in the lumbar region? The dorsal and ventral rami of lumbar spinal nerves supply the intertransversarii muscles. 15. A lesion to which nerve would produce the observed clinical sign involving the cervical vertebra? Describe the positioning at joints. A lesion to the cervical spinal nerves may cause weakness or sensory deficits at the intervertebral joints between cervical vertebrae. 16. A lesion to which nerve would produce the observed clinical sign involving the lumbar vertebra? Describe the positioning at joints. A lesion to the lumbar spinal nerves may cause motor and sensory deficits at the intervertebral joints between lumbar vertebrae. 17. Aside from generic trauma, what is a common injury mechanism for the cervical vertebrae? Hyperextension injuries, such as whiplash, are common in the cervical vertebrae. 18. Aside from generic trauma, what is a common injury mechanism for the lumbar vertebrae? Repetitive axial loading or improper lifting can cause disc herniation in the lumbar vertebrae. 19. Name a common action of the multifidus and erector spinae muscles. Both stabilise the spine and assist in extension. 20. Name a common action of the intertransversarii and interspinales muscles. Both assist in vertebral stabilisation and fine-tune movements. 21. Which segment of the paraxial mesoderm contributes to the cervical vertebrae? The sclerotome from cervical somites contributes to the cervical vertebrae. 22. Which segment of the paraxial mesoderm contributes to the lumbar vertebrae? The sclerotome from lumbar somites contributes to the lumbar vertebrae. 23. Which space does the spinal nerve exit the cervical vertebral column? The spinal nerve exits through the intervertebral foramen. 24. Which space does the spinal nerve exit the lumbar vertebral column? The spinal nerve exits through the intervertebral foramen. 25. What are the boundaries/contents of the cervical transverse foramen? Boundaries: Transverse processes. Contents: Vertebral artery and vein, and sympathetic plexus. 26. What are the boundaries/contents of the intervertebral foramen in the thoracic region? Boundaries: Superior and inferior notches, vertebral body, and zygapophyseal joints. Contents: Spinal nerves and dorsal root ganglia. 27. Name a sagittal plane movement of the cervical vertebrae. Flexion and extension occur in the sagittal plane. 28. Name a sagittal plane movement of the lumbar vertebrae. Flexion and extension occur in the sagittal plane. 29. What is the unilateral action of the erector spinae in the thoracic region? Lateral flexion of the thoracic vertebrae. 30. What is the bilateral action of the multifidus in the lumbar region? Extension of the lumbar vertebrae. 31. What is the most distal joint influenced by the sacral vertebrae? The sacroiliac joint is the most distal joint influenced. 32. Which joint of a vertebra does the anterior longitudinal ligament perform no action on? The anterior longitudinal ligament does not act on the atlanto-occipital joint. 33. Which movement can the posterior longitudinal ligament prevent/restrict/control? The posterior longitudinal ligament restricts hyperflexion. 34. Which of the pinned muscles is most likely to be challenged by active/passive insufficiency during rotation? The multifidus is most likely to be challenged. 35. Which muscles attach at the transverse processes of the thoracic vertebrae? The levator costarum, longissimus, and intertransversarii attach at the transverse processes. 36. Movements in which cardinal planes are permissible at cervical vertebrae? Sagittal: Flexion and extension. Frontal: Lateral flexion. Transverse: Rotation. 37. What movement occurs through the sagittal plane at the thoracic vertebrae during flexion? Flexion occurs, reducing the angle between vertebrae. 38. What type of muscle contraction does the multifidus perform during extension of the vertebral column? The multifidus performs concentric contraction. 39. How many vertebral segments does the multifidus cross in the lumbar spine? The multifidus crosses 3–4 vertebral segments in the lumbar spine. 40. How many vertebral segments does the semispinalis cross in the cervical region? The semispinalis crosses 5–6 vertebral segments in the cervical region. 41. Which vertebral region is the lumbar vertebrae most prone to degeneration? The lumbar region is most prone to degeneration. 42. Which vertebral region is the cervical vertebrae most affected by trauma? The cervical region is most affected by trauma. 43. Which vertebral element is the transverse foramen derived from? The transverse foramen is derived from the costal element of cervical vertebrae. 44. Which vertebral element is the spinous process derived from? The spinous process is derived from the neural arch. 45. Which movements are favoured/NOT possible between vertebrae in the cervical region? Favoured: Flexion, extension, lateral flexion, and rotation. NOT possible: None; cervical vertebrae allow all movements. 46. Which movements are favoured/NOT possible between vertebrae in the thoracic region? Favoured: Rotation. NOT possible: Significant lateral flexion due to rib attachments. 1. What evolutionary changes allowed mammals to develop true lumbar vertebrae, and how does this affect their movement compared to amphibians and reptiles? Mammals developed true lumbar vertebrae as limbs rotated under the body, enabling flexion- extension for galloping, unlike amphibians and reptiles, which rely on lateral undulation. 2. How do the shapes of the vertebral bodies differ between cervical, thoracic, and lumbar regions, and what functional significance do these differences have? Cervical: Small, oval for flexibility. Thoracic: Heart-shaped with rib facets for stability. Lumbar: Large, kidney-shaped for weight-bearing. 3. What is the functional role of the zygapophyseal joints in limiting or permitting specific movements in the lumbar spine? Zygapophyseal joints in the lumbar spine prevent rotation while permitting flexion and extension due to their interlocked radial orientation. 4. How does the orientation of the thoracic articular facets affect rotational movement, and why is lateral flexion constrained in this region? Thoracic facets are tangential, allowing rotation but limiting lateral flexion due to rib attachments. 5. What are the structural differences between the anterior and posterior components of the motion segment, and how do these differences influence their respective functions? Anterior: Vertebral bodies and discs, load-bearing. Posterior: Neural arch and ligaments, motion control. 6. How does the intervertebral disc respond to axial compression, and what are the consequences of weakening in the annulus fibrosus? Discs transmit loads via nucleus pulposus pressure. Weakening in the annulus fibrosus leads to disc herniation or bulging. 7. What anatomical features allow for coupled movements in the cervical vertebrae, and how does this impact neck mobility? Oblique facet angles (45°) allow coupled lateral flexion and rotation, increasing mobility. 8. How do Hox genes influence the morphological differences between vertebral regions, and what are some examples of region-specific features they regulate? Hox genes regulate segmentation and feature development, such as transverse foramina in cervical vertebrae and rib facets in thoracic vertebrae. 9. Describe the changes in intervertebral disc composition with ageing, and explain how these changes affect vertebral column mechanics and height. Water content decreases with age, reducing disc elasticity and height, leading to reduced shock absorption. 10. What binary features can be used to definitively identify a vertebra as cervical, thoracic, lumbar, or sacral? Cervical: Transverse foramina. Thoracic: Rib facets. Lumbar: Absence of both. Sacral: Fused vertebrae. 11. What mechanisms lead to vertebral injuries such as disc herniation or spondylolisthesis, and how are these injuries region-specific? Disc herniation: Axial loading in lumbar spine. Spondylolisthesis: Hyperextension injuries in lumbar or cervical spine. 12. How does the curvature of the vertebral column (e.g., lordosis and kyphosis) develop, and what functional advantages do these curvatures provide? Lordosis and kyphosis develop postnatally for shock absorption and weight distribution. 13. What is the relationship between vertebral morphology and injury mechanisms such as whiplash in the cervical spine or hyperextension injuries in the lumbar spine? Cervical spine: Mobile facets predispose to whiplash. Lumbar spine: Load-bearing predisposes to hyperextension injuries. 14. Explain how the nucleus pulposus and annulus fibrosus work together to maintain intervertebral disc function under load. Nucleus absorbs pressure, and annulus resists tension to maintain disc integrity under load. 15. Why do the lumbar vertebrae have a greater range of flexion and extension compared to rotation, and how does this relate to facet joint orientation? Lumbar facets are interlocked radially, permitting flexion-extension but restricting rotation. 16. What are the consequences of sacral vertebrae fusion on pelvic stability and lower limb biomechanics? Fusion stabilises the pelvis, enabling force transfer to the lower limbs. 17. How do coupled movements (e.g., lateral flexion with rotation) vary between cervical, thoracic, and lumbar regions, and what anatomical features facilitate or constrain these movements? Cervical: Coupled due to oblique facets. Thoracic: Limited by ribs. Lumbar: Minimal due to interlocked facets. 18. Describe the relationship between the anterior longitudinal ligament and posterior longitudinal ligament in maintaining vertebral column stability. The anterior ligament resists hyperextension, while the posterior ligament resists hyperflexion. 19. What adaptations are present in aquatic mammals' vertebral columns that differentiate them from terrestrial mammals? Flattened cervical vertebrae and retained lumbar regions for aquatic locomotion. 20. How do the load-bearing capacities of the cervical, thoracic, and lumbar vertebrae differ, and what structural features enable these capacities? Cervical: Lightweight for flexibility. Thoracic: Rib attachments for stability. Lumbar: Large vertebral bodies for weight-bearing. Lecture 3 1. Is the ligamentum flavum dorsal or ventral? The ligamentum flavum is dorsal, located posterior to the spinal cord. 2. Is the anterior longitudinal ligament dorsal or ventral? The anterior longitudinal ligament is ventral, running along the anterior surface of the vertebral bodies. 3. Is the posterior longitudinal ligament dorsal or ventral? The posterior longitudinal ligament is dorsal, located on the posterior aspect of the vertebral bodies within the vertebral canal. 4. Is the supraspinous ligament dorsal or ventral? The supraspinous ligament is dorsal, running along the tips of the spinous processes. 5. Is the ligamentum flavum pre-axial or post-axial? The ligamentum flavum is post-axial. 6. Is the anterior longitudinal ligament pre-axial or post-axial? The anterior longitudinal ligament is pre-axial. 7. Is the posterior longitudinal ligament pre-axial or post-axial? The posterior longitudinal ligament is pre-axial. 8. Is the supraspinous ligament pre-axial or post-axial? The supraspinous ligament is post-axial. 9. Describe the ligamentum flavum. The ligamentum flavum is an elastic ligament connecting the laminae of adjacent vertebrae. 10. Describe the anterior longitudinal ligament. The anterior longitudinal ligament is a broad, strong ligament running along the anterior vertebral bodies, preventing hyperextension. 11. Describe the posterior longitudinal ligament. The posterior longitudinal ligament is a narrow ligament along the posterior vertebral bodies, restricting hyperflexion. 12. Describe the supraspinous ligament. The supraspinous ligament connects the tips of the spinous processes, continuing as the ligamentum nuchae in the cervical region. 13. Which nerve supplies the erector spinae muscles? The dorsal rami of mixed spinal nerves supply the erector spinae muscles. 14. Which nerve supplies the semispinalis capitis muscle? The dorsal rami of cervical spinal nerves supply the semispinalis capitis muscle. 15. Which nerve supplies the rectus capitis posterior major? The dorsal ramus of C1 (suboccipital nerve) supplies the rectus capitis posterior major. 16. Which nerve supplies the obliquus capitis inferior? The dorsal ramus of C1 (suboccipital nerve) supplies the obliquus capitis inferior. 17. A lesion to which nerve would produce the observed clinical sign involving the ligamentum flavum? Describe the positioning at joints. A lesion to the spinal nerve roots compressed by a buckling ligamentum flavum may cause radiculopathy at the corresponding intervertebral foramen. 18. A lesion to which nerve would produce the observed clinical sign involving the rectus capitis posterior major? Describe the positioning at joints. 19. A lesion to the dorsal ramus of C1 would impair extension and ipsilateral rotation at the atlanto- occipital and atlantoaxial joints. 20. Aside from generic trauma, what is a common injury mechanism for lesions to the posterior longitudinal ligament? Chronic hyperflexion or herniated intervertebral discs may stress or compress the posterior longitudinal ligament. 21. Aside from generic trauma, what is a common injury mechanism for lesions to the ligamentum flavum? Degenerative thickening of the ligamentum flavum may compress spinal nerve roots, causing radiculopathy. 22. Name a common action of the rotatores and multifidus muscles. Both resist rotational movement and stabilise the vertebral column. 23. Name a common action of the semispinalis capitis and erector spinae muscles. Both extend the vertebral column and head. 24. Name a common action of the rectus capitis posterior major and obliquus capitis inferior muscles. Both perform ipsilateral rotation of the head and neck. 25. Which space does the anterior longitudinal ligament pass through along the vertebral column? The anterior longitudinal ligament passes along the anterior surface of the vertebral bodies. 26. Which space does the posterior longitudinal ligament pass through along the vertebral column? The posterior longitudinal ligament runs within the vertebral canal along the posterior vertebral bodies. 27. What are the boundaries/contents of the suboccipital triangle? Boundaries: Rectus capitis posterior major, obliquus capitis superior, obliquus capitis inferior. Contents: Vertebral artery and dorsal ramus of C1. 28. What are the boundaries/contents of the intervertebral foramen? Boundaries: Adjacent pedicles, vertebral bodies, and zygapophyseal joint. Contents: Spinal nerve roots and dorsal root ganglia. 29. Movements in which cardinal planes are permissible at the thoracic vertebral column? Sagittal: Flexion and extension. Frontal: Lateral flexion. Transverse: Rotation. 30. Movements in which cardinal planes are permissible at the cervical vertebral column? Sagittal: Flexion and extension. Frontal: Lateral flexion. Transverse: Rotation. 31. What type of muscle contraction does the erector spinae perform during flexion of the thoracolumbar spine? The erector spinae performs eccentric contraction during flexion to control movement. 32. What type of muscle contraction does the semispinalis capitis perform during extension of the cervical spine? The semispinalis capitis performs concentric contraction during extension. 33. How many vertebral segments does the multifidus cross in the lumbar spine? The multifidus crosses 3–4 vertebral segments in the lumbar spine. 34. How many vertebral segments does the semispinalis cross in the thoracic region? The semispinalis crosses 5–6 vertebral segments in the thoracic region. 35. Which vertebral region is the semispinalis primarily found in? The semispinalis is primarily found in the cervical and thoracic regions. 36. Which vertebral region is the multifidus most developed in? The multifidus is most developed in the lumbar region. 37. Which movements are favoured/NOT possible between vertebrae in the thoracic region? Favoured: Rotation. NOT possible: Significant lateral flexion due to rib constraints. 38. Which movements are favoured/NOT possible between vertebrae in the lumbar region? Favoured: Flexion and extension. NOT possible: Significant rotation due to interlocking facet joints. 1. What are the roles of the multi-segmental ligaments in the vertebral column? The anterior longitudinal ligament prevents hyperextension, the posterior longitudinal ligament prevents hyper-flexion, and the supraspinous ligament stabilises spinous processes. 2. How does the ligamentum flavum differ from the other multi-segmental ligaments? The ligamentum flavum is highly elastic, preventing buckling during flexion and avoiding compression of the spinal cord. 3. What is the significance of the zygapophyseal joint capsular ligaments? They stabilise the facet joints, restrict excessive movement, and protect the joint capsules. 4. Which intrinsic muscles are most sensitive to length changes? The intertransversarii and interspinous muscles have a high density of muscle spindles, making them highly sensitive to length changes. 5. What is the primary function of the transversospinales muscle group? The transversospinales group, including the rotatores, multifidus, and semispinalis, primarily resists rotational movements and stabilises the vertebral column. 6. Why are the multifidus muscles more prominent in the lumbar region? The multifidus muscles stabilise the lumbar spine during weight-bearing and prevent excessive movement. 7. What is the clinical relevance of the suboccipital triangle? The suboccipital triangle contains the vertebral artery and dorsal ramus of C1, structures that are critical for head movement, proprioception, and circulation. 8. What are the functions of the rectus capitis posterior major and minor muscles? The rectus capitis posterior major performs extension and ipsilateral rotation of the head, while the minor only performs extension. 9. How does the thoracolumbar fascia contribute to the stability of the lumbar spine? The thoracolumbar fascia forms a dense sheath reinforced by the latissimus dorsi and gluteus maximus, providing stability during movement and weight-bearing. 10. What are the three layers of the thoracolumbar fascia, and what do they enclose? Anterior: Covers the quadratus lumborum. Middle: Lies between the quadratus lumborum and the erector spinae. Posterior: Covers the erector spinae and transversospinales. 11. What is the functional difference between intrinsic and extrinsic back muscles? Intrinsic muscles stabilise and move the spine and are innervated by dorsal rami, while extrinsic muscles are limb-associated and innervated by ventral rami. 12. Which extrinsic muscles attach to the thoracolumbar fascia? The serratus posterior superior and serratus posterior inferior attach to the thoracolumbar fascia. 13. What movement does the erector spinae perform during lateral flexion? The erector spinae performs ipsilateral lateral flexion of the vertebral column. 14. How does the ligamentum nuchae differ from the supraspinous ligament? The ligamentum nuchae is an extension of the supraspinous ligament in the cervical region and provides attachment for muscles like the trapezius. 15. What is the function of the obliquus capitis inferior muscle? The obliquus capitis inferior performs ipsilateral rotation of the head at the atlanto-axial joint. 16. What is the importance of the interspinous ligament in vertebral stability? The interspinous ligament connects adjacent spinous processes, limiting excessive flexion. 17. How do the thoracic and lumbar regions differ in ligament strength? Thoracic ligaments are thinner and more flexible to allow breathing, while lumbar ligaments are thicker and stronger to resist high loads. 18. What is the clinical significance of the greater occipital nerve (C2)? The greater occipital nerve is often associated with neuralgia and headaches due to its proximity to the suboccipital region. 19. Which muscle group contributes most to postural stability during prolonged standing? The erector spinae group maintains postural stability through tonic contraction. 20. How do the radiate ligaments contribute to rib and vertebral stability? Radiate ligaments stabilise the costovertebral joints by anchoring the rib heads to the vertebral bodies. 1. What are the multi-segmental ligaments of the vertebral column? Anterior longitudinal ligament, posterior longitudinal ligament, and supraspinous ligament. 2. What is the role of the ligamentum flavum in vertebral function? It prevents buckling and compression of the spinal cord due to its elastic nature. 3. Which unisegmental ligaments are found in the vertebral column? Annulus fibrosus, interspinous ligament, intertransverse ligament, ligamentum flavum, and zygapophyseal joint capsular ligaments. 4. What innervates intrinsic back muscles? The dorsal rami of mixed spinal nerves. 5. What are the three subgroups of the transversospinales muscles? Rotatores, multifidus, and semispinalis. 6. Which muscles make up the erector spinae group, and what are their attachments? Spinalis (spinous processes), longissimus (neural components of transverse processes), and iliocostalis (costal elements and rib angles). 7. What is the unilateral action of the erector spinae muscles? Lateral flexion of the vertebral column. 8. What structures form the suboccipital triangle? Borders: Rectus capitis posterior major, obliquus capitis superior, and obliquus capitis inferior. Contents: Vertebral artery and dorsal ramus of C1. 9. What is the primary action of the rectus capitis posterior muscles? Extension of the atlanto-occipital joint. 10. What is the significance of the thoracolumbar fascia in the lumbar region? It provides strength and reinforcement, particularly through its posterior layer, supported by the latissimus dorsi and gluteus maximus. 11. What are the layers of the thoracolumbar fascia? Anterior, middle, and posterior layers, which join laterally to form the abdominal wall muscles. 12. Which extrinsic muscles are associated with the thoracolumbar fascia? Serratus posterior superior and serratus posterior inferior. 13. What distinguishes extrinsic from intrinsic back muscles? Extrinsic muscles are innervated by ventral rami and are outside the thoracolumbar fascia, while intrinsic muscles are innervated by dorsal rami and within it. 14. What is the action of the multifidus muscle in the lumbar region? Stabilisation and resistance to rotational movement. 15. What is the function of the splenius capitis muscle? Extension, lateral flexion, and ipsilateral rotation of the head and neck. 16. Which muscles are primarily responsible for resisting rotational movement in the thoracic spine? Rotatores and multifidus muscles. 17. How does the thoracic spine accommodate breathing through soft tissues? The thoracolumbar fascia in the thoracic region is thin and flexible to accommodate rib movement during breathing. 18. Which ligament replaces the supraspinous ligament in the cervical region? The ligamentum nuchae. 19. What is the function of the zygapophyseal joint capsular ligaments? They stabilise the joint and restrict excessive motion. 20. What is the primary action of the obliquus capitis superior muscle? Extension and lateral flexion of the head at the atlanto-occipital joint. Lecture 4 1. Is the anterior wall of the vertebral canal dorsal or ventral? The anterior wall of the vertebral canal is ventral. 2. Is the posterior wall of the vertebral canal dorsal or ventral? The posterior wall of the vertebral canal is dorsal. 3. Is the dura mater dorsal or ventral? The dura mater surrounds the spinal cord and is neither strictly dorsal nor ventral. 4. Is the arachnoid mater dorsal or ventral? The arachnoid mater surrounds the spinal cord and is neither strictly dorsal nor ventral. 5. Is the pia mater dorsal or ventral? The pia mater directly adheres to the spinal cord and is neither strictly dorsal nor ventral. 6. What does the anterior wall of the vertebral canal consist of? The anterior wall consists of vertebral bodies, intervertebral discs, and the posterior longitudinal ligament. 7. What does the posterior wall of the vertebral canal consist of? The posterior wall consists of the laminae, ligamentum flavum, and zygapophyseal joints. 8. Describe the dura mater. The dura mater is the tough outer meningeal layer forming a loose sheath around the spinal cord. 9. Describe the arachnoid mater. The arachnoid mater is a thin, web-like membrane lining the inside of the dura mater. 10. Describe the pia mater. The pia mater is the innermost meningeal layer, adhering to the spinal cord and nerve roots. 11. Which nerve supplies the structures in the epidural space? The recurrent meningeal nerves supply structures in the epidural space. 12. A lesion to which nerve would affect the dura mater? → Describe the positioning at joints. A lesion to the recurrent meningeal nerve may result in pain localised to the intervertebral joints and surrounding dura. 13. Aside from generic trauma, what is a common injury mechanism for the ligamentum flavum in the vertebral canal? Degeneration and thickening of the ligamentum flavum can lead to spinal stenosis. 14. Aside from generic trauma, what is a common injury mechanism for the posterior longitudinal ligament? Herniated intervertebral discs can compress and injure the posterior longitudinal ligament. 15. Name a common action of the denticulate ligaments. The denticulate ligaments stabilise the spinal cord by anchoring it laterally to the dura mater. 16. Name a common action of the filum terminale. The filum terminale anchors the spinal cord to the coccyx, preventing superior displacement. 17. Which segment of the vertebral canal contains the cauda equina? The lumbar and sacral segments of the vertebral canal contain the cauda equina. 18. Which segment of the vertebral canal contains the conus medullaris? The conus medullaris is found at the L1 vertebral level. 19. Which space does the epidural fat occupy in the vertebral canal? Epidural fat occupies the space between the dura mater and the bony walls of the vertebral canal. 20. Which space does the subarachnoid space occupy? The subarachnoid space lies between the arachnoid mater and the pia mater, filled with cerebrospinal fluid. 21. What are the boundaries/contents of the vertebral canal in the thoracic region? Boundaries: Vertebral bodies, pedicles, laminae, and intervertebral discs. Contents: Spinal cord, meninges, cerebrospinal fluid, and segmental nerves. 22. What are the boundaries/contents of the lumbar cistern? Boundaries: Continuation of the subarachnoid space between L1 and S2. Contents: Cauda equina, cerebrospinal fluid, and filum terminale. 23. Name a sagittal plane movement of the spinal cord within the vertebral canal. The spinal cord moves ventrally during flexion and dorsally during extension. 24. What is the unilateral action of the denticulate ligaments? The denticulate ligaments provide lateral stability to the spinal cord. 25. What is the bilateral action of the dura mater? The dura mater provides vertical stability to the spinal cord by anchoring to the foramen magnum and coccyx. 26. What is the most distal point of the spinal cord? The conus medullaris at the L1 vertebral level. 27. What is the most distal structure in the vertebral canal? The filum terminale externum, which attaches to the coccyx. 28. Which movement can the denticulate ligaments prevent/restrict/control? The denticulate ligaments restrict excessive lateral movement of the spinal cord. 29. Which movement can the filum terminale prevent/restrict/control? The filum terminale restricts superior displacement of the spinal cord. 30. Which of the meningeal layers continues beyond the spinal cord? The pia mater continues as the filum terminale, and the dura mater continues into the sacral canal. 31. Which vertebral element forms the sacral hiatus? The sacral hiatus is formed by the incomplete fusion of the laminae of the fifth sacral vertebra. 32. Movements in which cardinal planes are permissible for the spinal cord within the vertebral canal? Sagittal: Ventral and dorsal movement. Frontal: Minimal lateral movement restricted by the denticulate ligaments. 33. What type of movement occurs during flexion of the lumbar spine on the spinal cord? The spinal cord moves ventrally during lumbar flexion. 34. What type of muscle contraction supports the spinal cord during vertebral extension? Isometric contraction of the intrinsic back muscles supports the spinal cord during vertebral extension. 35. How many spinal nerve pairs arise from the vertebral canal? Thirty-one pairs of spinal nerves arise from the vertebral canal. 36. How many segments does the conus medullaris span in the fetal spine? The conus medullaris spans the entire vertebral column in the early fetal stage. 37. Which vertebral region is the epidural space widest? The epidural space is widest in the lumbar region. 38. Which vertebral region is the subarachnoid space most accessible? The subarachnoid space is most accessible in the lumbar cistern. 39. Which movements are favoured/NOT possible for the spinal cord within the vertebral canal? Favoured: Ventral and dorsal movement. NOT possible: Significant lateral movement due to the denticulate ligaments. 1. What is the significance of the sacral hiatus in clinical procedures? The sacral hiatus provides access to the epidural space for caudal epidural anaesthesia. 2. What are the attachments of the dura mater in the vertebral canal? The dura mater attaches firmly to the circumference of the foramen magnum, loosely to the posterior longitudinal ligament, and firmly to the dorsal surface of the coccyx. 3. What structures are found within the epidural space? The epidural space contains fat, the internal vertebral venous plexus, and segmental arteries. 4. Why is the lumbar cistern a preferred site for lumbar puncture? The lumbar cistern provides a large subarachnoid space at L3/4, with no risk of damaging the spinal cord due to its termination at L1. 5. How do the denticulate ligaments stabilise the spinal cord? The denticulate ligaments project laterally from the pia mater, anchoring to the dura mater, preventing excessive movement within the vertebral canal. 6. What is the clinical implication of a potential subdural space? The subdural space is a pathological space that may form during trauma, leading to subdural haematoma and compression of the spinal cord. 7. What is the function of the internal vertebral venous plexus? The internal vertebral venous plexus provides venous drainage from the spinal cord and surrounding tissues. 8. What are the segmental changes in the organisation of the spinal cord? The cervical and lumbar enlargements contain more grey matter for limb innervation, while the thoracic and sacral regions show autonomic nerve components. 9. Why does the vertebral canal vary in size across regions? The canal is larger in the cervical and lumbar regions to accommodate greater spinal cord volume and mobility, while it is smaller in the thoracic region due to rib attachments. 10. What is the significance of the filum terminale? The filum terminale anchors the spinal cord to the coccyx, maintaining longitudinal stability within the vertebral canal. 11. What is the role of cerebrospinal fluid in the subarachnoid space? Cerebrospinal fluid cushions the spinal cord, removes metabolic waste, and provides nutrients to the neural tissue. 12. What is the difference between the conus medullaris and the cauda equina? The conus medullaris is the tapered end of the spinal cord, while the cauda equina consists of spinal nerve roots extending below the conus. 13. What clinical condition may result from compression of the cauda equina? Cauda equina syndrome causes sensory and motor deficits in the lower limbs, bladder dysfunction, and perineal numbness. 14. What is the function of the arachnoid trabeculae in the subarachnoid space? The arachnoid trabeculae connect the arachnoid and pia mater, helping to stabilise the spinal cord within the cerebrospinal fluid. 15. What are the clinical applications of the epidural space in anaesthesia? The epidural space allows delivery of anaesthetics, providing segmental nerve block for procedures like labour and caesarean sections. 16. How does spinal cord movement within the vertebral canal affect back pain? Flexion moves the cord ventrally, and extension moves it dorsally, which can compress nerve roots and lead to flexion/extension-induced back pain. 17. What distinguishes the subarachnoid space from the epidural space? The subarachnoid space contains cerebrospinal fluid and is enclosed by the arachnoid and pia mater, while the epidural space lies outside the dura mater and contains fat and veins. 18. Why is the conus medullaris located at different vertebral levels during development? The vertebral column grows faster than the spinal cord, shifting the conus medullaris from the coccyx in early fetal life to L1 in adults. 19. What structural features protect the spinal cord within the vertebral canal? The vertebral canal walls, meninges (dura, arachnoid, pia mater), cerebrospinal fluid, and denticulate ligaments provide mechanical protection. 20. What is the significance of the last denticulate ligament at L1? The last denticulate ligament at L1 marks the end of lateral spinal cord stabilisation, after which the filum terminale provides longitudinal stability. 21. What is the relationship between spinal nerve segments and intervertebral foramina in the lumbar region? Lumbar spinal nerves descend 3–5 vertebral segments to reach their respective intervertebral foramina. 22. How do the white and grey matter distributions vary along the spinal cord? White matter increases towards the brain, while grey matter enlargements occur in the cervical and lumbar regions for limb innervation. 23. What are the autonomic components of the spinal cord? The intermediolateral horn contains sympathetic nerves in T1–L2 and parasympathetic nerves in S2– S4. 24. What structural adaptations support the cauda equina within the lumbar cistern? The cauda equina is surrounded by cerebrospinal fluid, which cushions and protects the nerve roots. 25. What are the boundaries and contents of the sacral canal? Boundaries: Sacral vertebrae, laminae, and sacral hiatus. Contents: Filum terminale externum, sacral nerve roots, fat, and veins. 1. What structures form the lateral wall of the vertebral canal? The lateral wall is formed by the pedicles and the intervertebral foramina. 2. How does the size of the vertebral canal vary by region, and why? The vertebral canal is larger in the cervical and lumbar regions to accommodate greater movement and larger spinal cord diameters, smaller in the thoracic region due to rib attachments, and reduced in the sacral region as the spinal cord ends. 3. What is the function of the epidural fat in the vertebral canal? The epidural fat cushions the spinal cord and provides space for the internal vertebral venous plexus. 4. What is the significance of the posterior longitudinal ligament in the vertebral canal? The posterior longitudinal ligament supports the posterior vertebral bodies and restricts hyperflexion. 5. What is the role of the internal vertebral venous plexus in the epidural space? The internal vertebral venous plexus drains venous blood from the vertebral column and spinal cord. 6. How do the attachments of the dura mater differ along the vertebral canal? The dura mater attaches firmly to the foramen magnum, loosely to the posterior longitudinal ligament, firmly to the dorsal surface of the coccyx, and forms dural sleeves around spinal nerves. 7. What is the clinical relevance of the lumbar cistern? The lumbar cistern contains the cauda equina and cerebrospinal fluid, making it an ideal site for lumbar puncture and spinal anaesthesia. 8. How does the dura mater contribute to anchoring the spinal cord? The dura mater forms sleeves around spinal nerves, anchoring them to intervertebral foramina and stabilising the cord. 9. What is the purpose of denticulate ligaments? Denticulate ligaments are lateral projections of pia mater that anchor the spinal cord to the dura mater, preventing excessive movement. 10. Why is the cauda equina located in the lumbar cistern? The cauda equina consists of nerve roots descending from the conus medullaris to their respective intervertebral foramina, located within the lumbar cistern for flexibility and movement. 11. What is the difference between the subdural and subarachnoid spaces? The subdural space is a potential space present only in pathology, while the subarachnoid space is a true space filled with cerebrospinal fluid. 12. What is the significance of the filum terminale internum and externum? The filum terminale internum is a continuation of pia mater anchoring the conus medullaris to the sacrum, while the filum terminale externum anchors the dural sac to the coccyx. 13. How do spinal nerves exit the vertebral canal? Spinal nerves exit the vertebral canal through intervertebral foramina, formed by adjacent vertebrae and the intervertebral discs. 14. What is the clinical significance of the epidural space in anaesthesia? The epidural space is used for administering anaesthesia during childbirth or surgery, as it allows for regional nerve blockade without puncturing the dura mater. 15. How do dorsal and ventral nerve roots contribute to spinal segmentation? Dorsal and ventral rootlets group into segmental spinal nerves, exiting through specific intervertebral foramina. 16. What changes occur to the spinal cord position during vertebral flexion and extension? During flexion, the spinal cord moves ventrally and cranially, while during extension, it moves dorsally and caudally. 17. How does the organisation of white and grey matter differ within the spinal cord? White matter (myelinated tracts) increases toward the brain, while grey matter (cell bodies) is prominent at cervical and lumbar enlargements due to limb innervation. 18. What is the role of the intermediolateral horn in the spinal cord? The intermediolateral horn contains autonomic neurons, responsible for sympathetic output in thoracic segments (T1-L2) and parasympathetic output in sacral segments (S2-S4). 19. How does the spinal cord length compare at different stages of development? The spinal cord extends to the full length of the vertebral column in the fetus, to S1 at birth, and to L1 in adults due to differential growth rates. 20. Why is the sacral hiatus clinically significant? The sacral hiatus is an entry point for caudal epidural anaesthesia, targeting sacral nerve roots without puncturing the dural sac. 21. What is the anatomical relationship between the dorsal root ganglion and the meninges? The dorsal root ganglion lies within the epidural space, where the meninges transition to peripheral nerve connective tissue. 22. How do the layers of connective tissue around peripheral nerves relate to the meninges? The epineurium, perineurium, and endoneurium of peripheral nerves are continuous with the dura mater, arachnoid, and pia mater, respectively. 23. What is the difference between the cervical and lumbar enlargements of the spinal cord? The cervical enlargement (C5-T1) innervates the upper limbs via the brachial plexus, while the lumbar enlargement (L1-S3) innervates the lower limbs via the lumbosacral plexus. 24. Why are lumbar punctures performed at the L3/L4 level? Lumbar punctures are performed below the conus medullaris to avoid spinal cord injury, utilising the larger subarachnoid space in the lumbar cistern. 25. How does the structure of the vertebral canal in the sacral region accommodate the filum terminale? The sacral canal contains the filum terminale externum, sacral nerve roots, and epidural fat, narrowing toward the sacral hiatus. 26. What is the functional importance of the conus medullaris? The conus medullaris is the tapered end of the spinal cord, from which nerve roots of the cauda equina arise to supply lower limb and pelvic structures. 27. How do the meningeal layers terminate at the coccyx? The pia mater continues as the filum terminale, the dura mater anchors to the coccyx, and the arachnoid ends at the level of the dural sac termination. 28. What is the clinical significance of the subarachnoid space during spinal block anaesthesia? The subarachnoid space is the target for spinal block anaesthesia, delivering a single-dose anaesthetic into cerebrospinal fluid for lower body procedures. 29. What changes occur to the spinal cord diameter along its length? The spinal cord diameter decreases caudally, with enlargements in the cervical and lumbar regions for limb innervation. 30. What is the role of cerebrospinal fluid in the subarachnoid space? Cerebrospinal fluid cushions the spinal cord, removes metabolic waste, and provides nutrients to the central nervous system. Lecture 5. Pre-Lab 1 1. Is the brachial plexus dorsal or ventral? The brachial plexus is ventral, located in the anterior region of the neck and axilla. 2. Is the lumbosacral plexus dorsal or ventral? The lumbosacral plexus is ventral, located in the lower abdominal and pelvic regions. 3. Is the axillary artery dorsal or ventral? The axillary artery is ventral, situated within the axilla. 4. Is the femoral triangle pre-axial or post-axial? The femoral triangle is pre-axial. 5. Is the popliteal fossa pre-axial or post-axial? The popliteal fossa is post-axial. 6. Describe the brachial plexus. The brachial plexus is a network of nerves arising from C5-T1, supplying the upper limb. 7. Describe the lumbosacral plexus. The lumbosacral plexus is a network of nerves arising from L1-S4, supplying the lower limb. 8. Describe the femoral triangle. The femoral triangle is an anatomical space bordered by the inguinal ligament, sartorius, and adductor longus, containing the femoral nerve, artery, and vein. 9. Describe the popliteal fossa. The popliteal fossa is a diamond-shaped space at the posterior knee, bordered by the hamstrings and gastrocnemius, containing the popliteal artery, vein, tibial nerve, and fibular nerve. 10. Which nerve supplies the muscles in the anterior compartment of the forearm? The median nerve supplies most muscles in the anterior compartment of the forearm, except for the flexor carpi ulnaris and part of the flexor digitorum profundus (ulnar nerve). 11. Which nerve supplies the muscles in the anterior compartment of the thigh? The femoral nerve supplies the muscles in the anterior compartment of the thigh. 12. Which nerve supplies the muscles in the posterior compartment of the thigh? The sciatic nerve supplies the muscles in the posterior compartment of the thigh. 13. A lesion to which nerve would produce the observed clinical sign involving the brachial plexus? → Describe the positioning at the upper limb. A lesion to the brachial plexus (e.g., Erb’s palsy) could result in weakness of the shoulder and elbow, leading to a "waiter's tip" deformity. 14. A lesion to which nerve would produce the observed clinical sign involving the femoral triangle? → Describe the positioning at the hip. A lesion to the femoral nerve may cause weakened hip flexion and knee extension, with sensory loss over the anterior thigh. 15. Aside from generic trauma, what is a common injury mechanism for the brachial plexus? Traction injuries, such as during childbirth or shoulder dislocations, commonly affect the brachial plexus. 16. Aside from generic trauma, what is a common injury mechanism for the popliteal fossa? Posterior knee dislocations or penetrating trauma can damage structures in the popliteal fossa. 17. Name a common action of the anterior compartment of the thigh. Extension of the knee. 18. Name a common action of the posterior compartment of the thigh. Flexion of the knee and extension of the hip. 19. Which segment of the spinal cord contributes to the brachial plexus? The brachial plexus arises from C5-T1 spinal segments. 20. Which segment of the spinal cord contributes to the lumbosacral plexus? The lumbosacral plexus arises from L1-S4 spinal segments. 21. Which space does the brachial plexus pass through in the neck? The brachial plexus passes through the posterior triangle of the neck. 22. Which space does the femoral nerve pass through in the thigh? The femoral nerve passes through the femoral triangle. 23. What are the boundaries/contents of the axilla? Boundaries: - Anterior: Pectoralis major and minor. - Posterior: Latissimus dorsi and subscapularis. - Medial: Serratus anterior and ribs. - Lateral: Intertubercular sulcus of the humerus. Contents: Axillary artery and vein, brachial plexus cords, lymph nodes, and fat. 24. What are the boundaries/contents of the quadrangular space? Boundaries: - Superior: Teres minor. - Inferior: Teres major. - Medial: Long head of triceps. - Lateral: Humeral surgical neck. Contents: Axillary nerve and posterior circumflex humeral artery. 25. Name a sagittal plane movement of the upper limb associated with the axilla. Flexion of the shoulder. 26. Name a sagittal plane movement of the lower limb associated with the femoral triangle. Flexion of the hip. 27. What is the unilateral action of the popliteus muscle? Medial rotation of the tibia on the femur during knee flexion. 28. What is the bilateral action of the gastrocnemius muscle? Plantarflexion of the ankle. 29. What is the most distal nerve arising from the brachial plexus? The ulnar nerve is the most distal major branch of the brachial plexus. 30. What is the most distal nerve arising from the lumbosacral plexus? The tibial nerve is one of the most distal major branches of the lumbosacral plexus. 31. Which movement can the axillary nerve prevent/restrict/control? The axillary nerve controls and prevents excessive abduction of the shoulder. 32. Which movement can the tibial nerve prevent/restrict/control? The tibial nerve prevents dorsiflexion at the ankle. 33. Which of the pinned muscles in the axilla is most likely to be challenged by active/passive insufficiency during shoulder flexion? The pectoralis major is most likely to be challenged. 34. Which muscles attach at the intertubercular sulcus of the humerus? The pectoralis major, latissimus dorsi, and teres major attach at the intertubercular sulcus. 35. Movements in which cardinal planes are permissible at the hip joint in relation to the femoral triangle? Sagittal: Flexion and extension. Frontal: Abduction and adduction. Transverse: Medial and lateral rotation. 36. What movement occurs through the sagittal plane at the knee joint by muscles in the popliteal fossa? Flexion of the knee. 37. What type of muscle contraction does the rectus femoris perform during hip flexion? The rectus femoris performs concentric contraction during hip flexion. 38. How many spinal segments contribute to the sciatic nerve? The sciatic nerve arises from L4-S3 spinal segments. 39. Which vertebral region is the femoral nerve most commonly affected by injury? The lumbar region, due to disc herniation or compression. 40. Which vertebral region is the tibial nerve most commonly affected by injury? The sacral region, often from pelvic fractures or trauma. 41. Which movements are favoured/NOT possible in the popliteal fossa? Favoured: Flexion and extension of the knee. NOT possible: Significant rotation due to ligament constraints. 1. What is the clinical relevance of the axilla as an anatomical space? The axilla houses the brachial plexus cords and axillary artery, making it a key site for nerve blocks, lymphatic drainage, and surgical approaches. 2. What is the significance of the quadrangular space in shoulder movement? The quadrangular space allows the axillary nerve and posterior circumflex humeral artery to supply the deltoid and teres minor, crucial for abduction and external rotation of the shoulder. 3. What structures pass through the triangular interval? The radial nerve and profunda brachii artery pass through the triangular interval, supplying the posterior arm compartment. 4. How is the posterior triangle of the neck relevant to clinical practice? The posterior triangle is a site for central venous access and contains the accessory nerve (CN XI), which can be injured during surgery. 5. What is the functional role of the saphenous nerve in the femoral triangle? The saphenous nerve provides cutaneous innervation to the medial leg and foot. 6. What is the significance of the adductor hiatus in vascular anatomy? The adductor hiatus allows the femoral vessels to pass into the popliteal fossa, transitioning into the popliteal artery and vein. 7. What is the difference between the pre-axial and post-axial veins in the lower limb? The pre-axial vein is the great saphenous vein (medial), while the post-axial vein is the small saphenous vein (posterior). 8. What is the role of the transverse cervical nerve in the posterior triangle? The transverse cervical nerve provides cutaneous innervation to the anterior neck. 9. How do the contents of the cubital fossa relate to venipuncture? The median cubital vein crosses the cubital fossa, making it a common site for venipuncture. 10. What is the importance of the great saphenous vein in clinical procedures? The great saphenous vein is commonly used for grafting in coronary artery bypass surgery. 11. Which nerve is most commonly compressed in the carpal tunnel, and how does this relate to the brachial plexus? The median nerve, a branch of the brachial plexus, is commonly compressed in the carpal tunnel, leading to carpal tunnel syndrome. 12. What is the anatomical basis for sciatic nerve injuries in the gluteal region? Improper gluteal intramuscular injections can injure the sciatic nerve, which arises from the lumbosacral plexus. 13. What is the function of the subclavian artery in the posterior triangle of the neck? The subclavian artery supplies blood to the upper limb and neck via its branches, including the vertebral artery and thyrocervical trunk. 14. Why is the popliteal fossa a critical region for vascular surgery? The popliteal artery is prone to aneurysms and injuries, making the popliteal fossa important for vascular access and bypass surgeries. 15. What is the significance of the intertubercular sulcus in relation to the brachial plexus? The intertubercular sulcus serves as an attachment site for muscles (pectoralis major, latissimus dorsi, and teres major) that influence movements innervated by the brachial plexus. 16. What is the relationship between the femoral sheath and femoral hernias? The femoral sheath contains the femoral artery, vein, and lymphatics, but not the nerve, and is a common site for femoral hernias, especially in females. 17. What is the clinical relevance of the cervical plexus in nerve blocks? The cervical plexus, located in the posterior triangle, is targeted in nerve blocks for neck surgeries and regional anaesthesia. 18. What are the implications of axillary lymph node dissection in cancer treatment? Axillary lymph node dissection can lead to lymphedema and injury to the long thoracic or thoracodorsal nerves. 19. How does the tibial nerve contribute to plantarflexion in the lower limb? The tibial nerve innervates the gastrocnemius, soleus, and other posterior compartment muscles, enabling plantarflexion at the ankle. 20. What are the consequences of radial nerve injury in the triangular interval? Radial nerve injury can result in wrist drop, characterised by the inability to extend the wrist and fingers. 21. How does the femoral nerve contribute to the stability of the hip joint? The femoral nerve innervates muscles like the iliopsoas, which flex the hip and stabilise it during walking. 22. What is the importance of the long thoracic nerve in upper limb function? The long thoracic nerve innervates the serratus anterior, preventing scapular winging and allowing protraction of the scapula. 23. How do the roots of the brachial plexus relate to scalene muscles? The roots of the brachial plexus (C5-T1) pass between the anterior and middle scalene muscles, a key landmark for regional anaesthesia. 24. What is the functional significance of the superficial peroneal nerve in the leg? The superficial peroneal nerve innervates the lateral compartment muscles, enabling eversion of the foot. 25. What is the role of the posterior tibial artery in the popliteal fossa? The posterior tibial artery supplies blood to the posterior compartment of the leg and plantar surface of the foot. Lecture 6. Pre Lab 2 1. Is the coracobrachialis dorsal or ventral? The coracobrachialis is ventral. 2. Is the brachialis dorsal or ventral? The brachialis is ventral. 3. Is the biceps brachii dorsal or ventral? The biceps brachii is ventral. 4. Is the triceps brachii dorsal or ventral? The triceps brachii is dorsal. 5. Is the deltoid dorsal or ventral? The deltoid has both dorsal and ventral components, depending on the fibres. 6. Is the musculocutaneous nerve pre-axial or post-axial? The musculocutaneous nerve is pre-axial. 7. Is the radial nerve pre-axial or post-axial? The radial nerve is post-axial. 8. Name the origin, insertion, and key function of the coracobrachialis. The coracobrachialis originates from the coracoid process of the scapula and inserts into the midshaft of the humerus. Its key function is flexion and internal rotation of the shoulder joint. 9. Name the origin, insertion, and key function of the brachialis. The brachialis originates from the distal anterior surface of the humerus and inserts into the ulnar tuberosity. Its key function is flexion of the elbow. 10. Name the origin, insertion, and key function of the biceps brachii. The biceps brachii has two heads: - Short head: Originates from the coracoid process. - Long head: Originates from the supraglenoid tubercle via the bicipital groove. Both insert into the radial tuberosity and bicipital aponeurosis. Its key functions are flexion of the elbow and supination of the forearm. 11. Name the origin, insertion, and key function of the triceps brachii. The triceps brachii has three heads: - Long head: Originates from the infraglenoid tubercle. - Lateral head: Originates from the posterior humerus above the spiral groove. - Medial head: Originates from the posterior humerus below the spiral groove. All insert into the olecranon process of the ulna. Its key function is extension of the elbow. 12. Which nerve supplies the coracobrachialis? The musculocutaneous nerve (C5-6). 13. Which nerve supplies the brachialis? The musculocutaneous nerve (C5-6), with minor contribution from the radial nerve. 14. Which nerve supplies the biceps brachii? The musculocutaneous nerve (C5-6). 15. Which nerve supplies the triceps brachii? The radial nerve (C5-T1). 16. A lesion to which nerve would produce the observed clinical sign involving the biceps brachii? → Describe the positioning at joints. A lesion to the musculocutaneous nerve would weaken elbow flexion and supination, with the forearm positioned in pronation. 17. A lesion to which nerve would produce the observed clinical sign involving the triceps brachii? → Describe the positioning at joints. A lesion to the radial nerve would cause weakened elbow extension, with the elbow remaining partially flexed. 18. Aside from generic trauma, what is a common injury mechanism for the radial nerve? Compression in the spiral groove of the humerus, commonly due to midshaft fractures. 19. Aside from generic trauma, what is a common injury mechanism for the musculocutaneous nerve? Entrapment as it pierces the coracobrachialis muscle. 20. Name a common action of the coracobrachialis and biceps brachii. Flexion and internal rotation at the glenohumeral joint. 21. Name a common action of the triceps brachii and anconeus. Extension at the elbow. 22. Which segment of the brachial plexus does the musculocutaneous nerve arise from? The musculocutaneous nerve arises from the lateral cord of the brachial plexus. 23. Which segment of the brachial plexus does the radial nerve arise from? The radial nerve arises from the posterior cord of the brachial plexus. 24. Which space does the radial nerve pass through in the arm? The radial nerve passes through the triangular interval. 25. Which space does the musculocutaneous nerve pass through in the arm? The musculocutaneous nerve pierces the coracobrachialis. 26. What are the boundaries/contents of the quadrangular space? Boundaries: - Superior: Teres minor. - Inferior: Teres major. - Medial: Long head of triceps. - Lateral: Humeral surgical neck. Contents: Axillary nerve and posterior circumflex humeral artery. 27. What are the boundaries/contents of the triangular interval? Boundaries: - Superior: Teres major. - Medial: Long head of triceps. - Lateral: Lateral head of triceps or humerus. Contents: Radial nerve and profunda brachii artery. 28. Name a sagittal plane movement of the biceps brachii. Flexion of the elbow. 29. Name a sagittal plane movement of the triceps brachii. Extension of the elbow. 30. What is the unilateral action of the coracobrachialis? Flexion and adduction of the shoulder. 31. What is the bilateral action of the biceps brachii? Flexion and supination of the forearm. 32. What is the most distal joint the brachialis acts on? The elbow joint. 33. What is the most distal joint the triceps brachii acts on? The elbow joint. 34. Which movement can the musculocutaneous nerve prevent/restrict/control? The musculocutaneous nerve controls and prevents excessive elbow extension. 35. Which movement can the radial nerve prevent/restrict/control? The radial nerve controls and prevents excessive elbow flexion. 36. Which of the pinned muscles in the anterior arm is most likely to be challenged by active/passive insufficiency during elbow flexion? The biceps brachii. 37. Which muscles attach at the coracoid process of the scapula? The coracobrachialis, biceps brachii (short head), and pectoralis minor. 38. Movements in which cardinal planes are permissible at the glenohumeral joint? Sagittal: Flexion and extension. Frontal: Abduction and adduction. Transverse: Internal and external rotation. 39. What movement occurs through the sagittal plane at the elbow by the brachialis? Flexion of the elbow. 40. What type of muscle contraction does the biceps brachii perform during supination of the forearm? The biceps brachii performs concentric contraction during supination. 41. How many spinal segments contribute to the musculocutaneous nerve? The musculocutaneous nerve arises from C5-C7 spinal segments. 42. How many spinal segments contribute to the radial nerve? The radial nerve arises from C5-T1 spinal segments. 43. Which vertebral region is the musculocutaneous nerve most commonly affected by injury? The cervical region, due to brachial plexus injuries. 44. Which vertebral region is the radial nerve most commonly affected by injury? The thoracic region, particularly at the spiral groove of the humerus. 45. Which movements are favoured/NOT possible at the elbow joint by anterior arm muscles? Favoured: Flexion and supination. NOT possible: Extension. 1. What is the relationship between the coracobrachialis and the musculocutaneous nerve? The musculocutaneous nerve pierces the coracobrachialis muscle, making it a key landmark for identifying this nerve. 2. How does the biceps brachii contribute to shoulder stability? The long head of the biceps brachii stabilises the shoulder joint by acting as a dynamic stabiliser of the glenohumeral joint, particularly during abduction and external rotation. 3. Why is the brachialis considered a primary mover of elbow flexion? The brachialis is considered the primary mover of elbow flexion because it inserts closer to the joint (ulnar tuberosity), providing consistent force regardless of forearm position. 4. What is the functional significance of the bicipital aponeurosis? The bicipital aponeurosis protects underlying structures in the cubital fossa, such as the median nerve and brachial artery, and assists in transmitting force during supination. 5. What is the role of the anconeus in elbow function? The anconeus assists the triceps brachii in elbow extension and stabilises the elbow joint during forearm pronation and supination. 6. What is the anatomical significance of the spiral groove of the humerus? The spiral groove houses the radial nerve and deep brachial artery, making it a common site of nerve compression or injury in humeral fractures. 7. How does the deltoid muscle relate to the proximal upper limb compartmental anatomy? The deltoid crosses the glenohumeral joint and assists with flexion (anterior fibres), extension (posterior fibres), and abduction (middle fibres), complementing the actions of the anterior and posterior compartments. 8. What is the role of the long head of the triceps brachii in shoulder movement? The long head of the triceps brachii crosses the glenohumeral joint and contributes to shoulder extension and adduction in addition to elbow extension. 9. How does the radial nerve’s course make it susceptible to injury? The radial nerve travels through the triangular interval and the spiral groove, where it is prone to compression or damage during midshaft humeral fractures or prolonged pressure. 10. Why is the coracoid process an important bony landmark for upper limb muscles? The coracoid process serves as the origin for the coracobrachialis, short head of the biceps brachii, and pectoralis minor, making it a key attachment site for muscles influencing shoulder and arm movement. 11. What is the clinical relevance of the triangular interval? The triangular interval contains the radial nerve and profunda brachii artery, both of which are at risk during humeral fractures or deep soft tissue injuries in the posterior arm. 12. How does the musculocutaneous nerve transition into the forearm? The musculocutaneous nerve becomes the lateral cutaneous nerve of the forearm, providing sensory innervation to the lateral forearm. 13. What is the importance of the olecranon process in the posterior compartment of the arm? The olecranon process serves as the insertion site for the triceps brachii and anconeus, allowing these muscles to generate force for elbow extension. 14. Which functional movement would be compromised by an injury to the musculocutaneous nerve? Elbow flexion and forearm supination would be significantly weakened, as the biceps brachii and brachialis would be affected. 15. Which functional movement would be compromised by an injury to the radial nerve? Elbow extension would be weakened due to triceps brachii impairment, along with wrist and finger extension, leading to wrist drop. 16. How does the bicipital groove influence the action of the biceps brachii? The bicipital groove guides the tendon of the long head of the biceps brachii, allowing it to stabilise and assist with shoulder flexion. 17. What is the significance of the axillary nerve in relation to the proximal upper limb? The axillary nerve innervates the deltoid and teres minor, enabling shoulder abduction and external rotation, and is at risk of injury in surgical neck fractures. 18. What is the functional role of the pectoralis minor in relation to anterior compartment muscles? The pectoralis minor stabilises the scapula by drawing it anteriorly and inferiorly, aiding the coracobrachialis and biceps brachii during arm movements. 19. What anatomical variations in the biceps brachii can affect its function? A third head of the biceps brachii is a common anatomical variation, which may enhance supination and elbow flexion strength. 20. How does the insertion of the brachialis differ from the biceps brachii, and why is this important? The brachialis inserts into the ulnar tuberosity, while the biceps brachii inserts into the radial tuberosity, making the brachialis unaffected by forearm pronation or supination. 21. Why is the long head of the biceps brachii considered a stabiliser of the glenohumeral joint? The long head of the biceps brachii runs through the bicipital groove and attaches to the supraglenoid tubercle, acting as a stabiliser during shoulder movement. 22. What is the significance of the profunda brachii artery in the posterior compartment of the arm? The profunda brachii artery supplies blood to the triceps brachii and accompanies the radial nerve in the spiral groove, making it critical for posterior arm function. 23. How does the origin of the lateral head of the triceps brachii influence its action? The lateral head originates above the spiral groove, providing significant force for elbow extension, especially during rapid or high-resistance movements. 24. Why is the anterior compartment of the arm more susceptible to compression injuries? The anterior compartment contains the musculocutaneous nerve and brachial artery, which are close to the humerus and prone to compression from swelling or trauma. 25. What is the functional importance of the medial head of the triceps brachii? The medial head provides continuous force during elbow extension, particularly in low-resistance or repetitive activities. Lecture 7. PreLab 4. 1. Is the serratus anterior dorsal or ventral? The serratus anterior is ventral. 2. Is the pectoralis minor dorsal or ventral? The pectoralis minor is ventral. 3. Is the trapezius dorsal or ventral? The trapezius is dorsal. 4. Is the rhomboids group dorsal or ventral? The rhomboids group is dorsal. 5. Is the levator scapulae dorsal or ventral? The levator scapulae is dorsal. 6. Is the latissimus dorsi dorsal or ventral? The latissimus dorsi is dorsal. 7. Is the pectoralis major dorsal or ventral? The pectoralis major is ventral. 8. Is the subclavius dorsal or ventral? The subclavius is ventral. 9. Is the serratus anterior pre-axial or post-axial? The serratus anterior is pre-axial. 10. Is the trapezius pre-axial or post-axial? The trapezius is post-axial. 11. Is the latissimus dorsi pre-axial or post-axial? The latissimus dorsi is post-axial. 12. Name the origin, insertion, and key function of the serratus anterior. Origin: Outer surfaces of the upper 8-9 ribs. Insertion: Medial border of the scapula. Key function: Protraction and upward rotation of the scapula. 13. Name the origin, insertion, and key function of the trapezius. Origin: Occipital bone, nuchal ligament, and spinous processes of C7-T12. Insertion: Lateral third of the clavicle, acromion, and spine of the scapula. Key function: Elevation, depression, retraction, and upward rotation of the scapula. 14. Name the origin, insertion, and key function of the pectoralis minor. Origin: Ribs 3-5 near their costal cartilages. Insertion: Coracoid process of the scapula. Key function: Protraction and depression of the scapula. 15. Name the origin, insertion, and key function of the rhomboids group. Origin: Spinous processes of C7-T5. Insertion: Medial border of the scapula. Key function: Retraction and downward rotation of the scapula. 16. Which nerve supplies the serratus anterior? The long thoracic nerve (C5, C6, C7). 17. Which nerve supplies the trapezius? The spinal accessory nerve (cranial nerve XI). 18. Which nerve supplies the latissimus dorsi? The thoracodorsal nerve (C6, C7, C8). 19. Which nerve supplies the levator scapulae? The dorsal scapular nerve (C4, C5). 20. Which nerve supplies the pectoralis major? The medial and lateral pectoral nerves (C5-T1). 21. A lesion to which nerve would produce the observed clinical sign involving the trapezius? → Describe the positioning at joints. A lesion to the spinal accessory nerve would cause drooping of the shoulder and difficulty elevating the scapula. 22. A lesion to which nerve would produce the observed clinical sign involving the serratus anterior? → Describe the positioning at joints. A lesion to the long thoracic nerve would cause winging of the scapula, especially during arm abduction. 23. Aside from generic trauma, what is a common injury mechanism for the long thoracic nerve? Compression or damage during surgery, such as mastectomy or axillary lymph node dissection. 24. Aside from generic trauma, what is a common injury mechanism for the thoracodorsal nerve? Injury during axillary surgery or trauma affecting the posterior axillary region. 25. Name a common action of the serratus anterior and trapezius. Upward rotation of the scapula. 26. Name a common action of the rhomboids and levator scapulae. Downward rotation and retraction of the scapula. 27. Which space does the spinal accessory nerve pass through in the neck? The spinal accessory nerve passes through the posterior triangle of the neck. 28. What are the boundaries/contents of the axilla? Boundaries: - Anterior: Pectoralis major and minor. - Posterior: Latissimus dorsi and subscapularis. - Medial: Serratus anterior. - Lateral: Intertubercular sulcus of the humerus. Contents: Axillary artery, vein, brachial plexus cords, and lymph nodes. 29. Name a sagittal plane movement of the pectoralis major. Flexion of the shoulder. 30. Name a sagittal plane movement of the latissimus dorsi. Extension of the shoulder. 31. What is the unilateral action of the levator scapulae? Elevation and downward rotation of the scapula. 32. What is the bilateral action of the trapezius? Extension of the cervical spine. 33. What is the most distal joint influenced by the pectoralis major? The glenohumeral joint. 34. What is the most distal joint influenced by the latissimus dorsi? The glenohumeral joint. 35. Which movement can the serratus anterior prevent/restrict/control? The serratus anterior prevents scapular winging during arm abduction. 36. Which movement can the trapezius prevent/restrict/control? The trapezius prevents excessive scapular protraction. 37. Which of the pinned muscles in the scapula region is most likely to be challenged by active/passive insufficiency during overhead reaching? The serratus anterior. 38. Which muscles attach at the coracoid process of the scapula? The pectoralis minor, coracobrachialis, and short head of the biceps brachii. 39. Movements in which cardinal planes are permissible at the glenohumeral joint? Sagittal: Flexion and extension. Frontal: Abduction and adduction. Transverse: Internal and external rotation. 40. What movement occurs through the sagittal plane at the shoulder by the deltoid? Flexion and extension of the shoulder. 41. What type of muscle contraction does the serratus anterior perform during scapular protraction? The serratus anterior performs concentric contraction during scapular protraction. 42. How many spinal segments contribute to the long thoracic nerve? The long thoracic nerve arises from C5, C6, and C7. 43. How many spinal segments contribute to the dorsal scapular nerve? The dorsal scapular nerve arises from C4 and C5. 44. Which vertebral region is the trapezius most commonly affected by postural dysfunction? The cervical and thoracic regions, due to prolonged forward head posture. 45. Which movements are favoured/NOT possible at the scapulothoracic joint? Favoured: Protraction, retraction, elevation, depression, upward rotation, and downward rotation. NOT possible: Flexion and extension. 1. How does the trapezius muscle contribute to scapular stability? The trapezius stabilises the scapula during movements of the upper limb, preventing unwanted protraction or depression. 2. What is the functional significance of the long thoracic nerve in scapular movement? The long thoracic nerve innervates the serratus anterior, enabling scapular protraction and upward rotation, critical for overhead arm movements. 3. How does the rhomboids group support the posture of the scapula? The rhomboids retract and medially rotate the scapula, maintaining its position against the thoracic wall and supporting posture. 4. Why is the coracoid process important for muscle attachment? The coracoid process serves as the origin for the pectoralis minor, coracobrachialis, and short head of the biceps brachii, anchoring muscles involved in scapular and arm movements. 5. What is the role of the levator scapulae in cervical spine movements? The levator scapulae assists in elevating the scapula and, when acting unilaterally, laterally flexes the cervical spine. 6. How does the pectoralis major assist with scapular protraction? The pectoralis major pulls the humerus anteriorly, indirectly assisting the serratus anterior in scapular protraction. 7. What is the role of the subclavius in the pectoral girdle? The subclavius stabilises the clavicle by anchoring it to the first rib, preventing excessive elevation or dislocation of the clavicle. 8. How does the latissimus dorsi influence scapular movement? The latissimus dorsi indirectly affects the scapula by pulling the humerus posteriorly, contributing to scapular retraction and downward rotation. 9. Which muscles contribute to upward rotation of the scapula? The serratus anterior and trapezius (upper and lower fibres) coordinate to rotate the scapula upward during arm elevation. 10. Which muscles contribute to downward rotation of the scapula? The rhomboids, levator scapulae, latissimus dorsi, and pectoralis minor coordinate to rotate the scapula downward during arm adduction or pulling movements. 11. What is the clinical relevance of scapular winging? Scapular winging occurs due to weakness or paralysis of the serratus anterior, often caused by long thoracic nerve injury, impairing arm elevation. 12. How does the thoracodorsal nerve influence upper limb function? The thoracodorsal nerve innervates the latissimus dorsi, enabling powerful extension, adduction, and medial rotation of the humerus. 13. What is the anatomical relationship between the trapezius and accessory nerve? The accessory nerve (CN XI) courses through the posterior triangle of the neck to innervate the trapezius, making it susceptible to injury during surgical procedures. 14. How do the scapulothoracic and glenohumeral joints coordinate during arm elevation? The scapulothoracic joint provides a stable base for the glenohumeral joint, with coordinated upward rotation of the scapula and abduction of the humerus. 15. What is the role of the rotator cuff muscles in scapular stability? The rotator cuff muscles stabilise the glenohumeral joint, ensuring the humeral head remains centred in the glenoid fossa during scapular movements. 16. How does the trapezius differ in its actions along its upper, middle, and lower fibres? - Upper fibres: Elevate the scapula. - Middle fibres: Retract the scapula. - Lower fibres: Depress and assist in upward rotation of the scapula. 17. What is the clinical significance of the medial pectoral nerve? The medial pectoral nerve innervates the pectoralis minor and major, with injury resulting in weakened scapular protraction and depression. 18. Which muscles attach at the medial border of the scapula? The serratus anterior, rhomboids, and levator scapulae attach at the medial border of the scapula, influencing its position and movement. 19. What is the role of the clavicle in transmitting forces through the pectoral girdle? The clavicle transmits forces from the upper limb to the axial skeleton, maintaining the scapula's position during arm movements. 20. How does poor posture affect the function of the pectoral girdle musculature? Poor posture, such as rounded shoulders, shortens the pectoralis minor and weakens the rhomboids and trapezius, reducing scapular stability and mobility. 21. What is the significance of the scapular notch in nerve passage? The scapular notch houses the suprascapular nerve, which innervates the supraspinatus and infraspinatus muscles, contributing to scapular and arm movements. 22. How do muscle imbalances in the pectoral girdle lead to dysfunction? Over-activation of the pectoralis minor or weakness of the trapezius and serratus anterior can cause scapular dyskinesis, impairing shoulder mechanics. 23. What is the role of the thoracic spine in supporting scapular movement? The thoracic spine provides a stable base for scapular movements, with thoracic extension facilitating upward rotation and arm elevation. 24. How does the range of motion in the scapulothoracic joint affect upper limb function? Limited scapulothoracic motion, such as reduced upward rotation, restricts overhead reaching and places increased strain on the glenohumeral joint. 25. Why are coordinated scapular movements essential for shoulder abduction? Coordinated upward rotation, protraction, and posterior tilt of the scapula prevent impingement of structures in the subacromial space during shoulder abduction. Synthesis of Week 1 Lectures 1. How do the vertebral column ligaments contribute to stability during scapular movements? Ligaments such as the supraspinous and interspinous ligaments maintain the alignment of the thoracic spine, providing a stable base for scapular movements. 2. What is the functional relationship between the thoracolumbar fascia and the latissimus dorsi? The thoracolumbar fascia anchors the latissimus dorsi, enhancing its ability to extend, adduct, and medially rotate the humerus while stabilising the lower spine. 3. How do the intrinsic back muscles complement the pectoral girdle muscles during posture maintenance? Intrinsic back muscles such as the multifidus and erector spinae stabilise the vertebral column, allowing the pectoral girdle muscles to efficiently control scapular and arm movements. 4. How do the dorsal scapular nerve and long thoracic nerve function together to stabilise the scapula? The dorsal scapular nerve innervates the rhomboids and levator scapulae for retraction and elevation, while the long thoracic nerve activates the serratus anterior for protraction and upward rotation, achieving dynamic scapular stability. 5. What role does the thoracic vertebrae play in scapular movements? The thoracic vertebrae provide attachment points for muscles such as the trapezius and rhomboids, facilitating scapular elevation, depression, and retraction. 6. How does thoracic kyphosis impact scapular movement? Excessive kyphosis limits scapular retraction and upward rotation, reducing overhead range of motion and increasing the risk of impingement. 7. Why is the posterior longitudinal ligament relevant during scapular protraction and retraction? The posterior longitudinal ligament mai