Regional Anatomy of the Trunk PDF

Regional Anatomy: The Trunk Biosciences for Human Health B  We acknowledge and pay our respects to the Kaurna people, the traditional custodians whose ancestral lands we gather on. We acknowledge the deep feelings of attachment and relationship of the Kaurna people to country and we respec...

Regional Anatomy: The Trunk Biosciences for Human Health B  We acknowledge and pay our respects to the Kaurna people, the traditional custodians whose ancestral lands we gather on. We acknowledge the deep feelings of attachment and relationship of the Kaurna people to country and we respect and value their past, present and ongoing connection to the land and cultural beliefs. Learning Objectives Explain what is meant by “regional anatomy” and list the major body systems which contribute to the region of the back. Explain the general function of each system and how they relate to each other. Recognise the vertebral column, its regions, curvatures, joints, characteristic vertebral features and their functions. Distinguish spinal movements, the planes in which they occur, and muscles that generate these movements. Briefly explain the developmental process of the vertebral column. Identify the innervation and blood supply of the structures of the trunk. Self-Directed Learning Please complete/watch the following online interactives & videos to recap and build on your knowledge: Interactive Books Regional Anatomy of the Trunk Videos Vertebral Column Movements Innervation of the Trunk Blood Supply of the Trunk Live Interactions in the Lecture Please use your laptop/tablet/phone to open up the lecture within the Echo360 tab in MyUni. Every lecture will contain interactive elements for you to check your understanding of concepts in real-time. All answers are anonymous. Regional Anatomy of the Trunk* *Primary focus on the back and the vertebral column in this lecture What is Regional Anatomy? Region Study by regions (as opposed to body systems), e.g. Thoracic region region of head and neck, trunk, limbs You will see parts of multiple body systems in a given region Regional anatomy is important to understand the Systems interactions of different systems in a given anatomical Skeletal location Integumentary Clinically, it is important to differentially diagnose Respiratory conditions when symptoms are localised to a particular Cardiovascular region & Nervous Region of the Trunk Can be divided into: The back (posterior/dorsal trunk) The anterior/ventral body cavities Thoracic cavity Abdominopelvic cavity Major Body Systems of the Posterior Trunk Integumentary: Protection and sensation Skin and subcutaneous tissue Muscular: Stabilises body position and produces movement Moving and maintaining the position of the axial skeleton Muscles of ventilation, i.e. intercostals Skeletal: Protection of organs, facilitates movement Vertebral column: Includes vertebrae, intervertebral discs and associated ligaments Sternum and ribs Nervous: Receives, interprets and elicits response to information Spinal cord and meninges Nerves The Vertebral Column Vertebral Column Functions Provides a framework for the body as part of the axial skeleton Facilitates weight transfer Protects the spinal cord and organs Provides a location for muscle attachment General bone functions Blood cell formation Calcium store Veritas Health 2023 Vertebral Column Structure Made up of bone and connective tissue: Thirty-three vertebrae in a child, and 26 in an adult: 7x cervical 12x thoracic 5x lumbar 5x sacral (fused in adults to form one) 4x coccygeal (fused in adults to form one) Intravertebral discs, made of fibrocartilage, that are between the vertebrae Components of a Typical Vertebrae Vertebral body: Disc-shaped anterior portion Weight-bearing part of the vertebrae Superior and inferior surfaces attached to intravertebral discs Vertebral arch: The pedicles project posteriorly from the vertebral body and unite with the lamina to form the arch Houses the spinal cord and its protective tissues Processes Transverse processes: project laterally from lamina – serve as muscle attachment sites Spinous process: projects posteriorly from lamina – serve as muscle attachment site Superior & inferior articular processes (x2 of each) – serve as articulation sites of vertebrae above and below Comparison of Cervical, Thoracic & Lumbar Vertebrae Vertebral Column Regions The neck region: Cervical vertebrae First two vertebrae (C1 & C2, known as the atlas and axis, respectively) are specialised in structure to facilitate side-to-side movement of the head The chest region: Thoracic vertebrae Articulate with the ribs Lumbar region: Largest and strongest unfused vertebrae as the amount of body weight supported, increases toward the inferior end of the vertebral column Sacral & coccygeal region: Serves as a strong foundation for the pelvic girdle Vertebral Column Curvatures When viewed in a sagittal plane, the four normal curves of the vertebral column are visible Relative to the anterior (front) surface of the body: Cervical and lumbar curves are convex (bulge out) Thoracic and sacral curves are concave (cup inward) Function of vertebral curves: Increase vertebral column strength Helps to maintain balance in an upright position Shock-absorption during walking Protect vertebrae against fracture Cervical and lumbar curves may be progressively lost in old age Vertebral Column Joints There are 2 main types of joints in the vertebral column: Intervertebral discs and vertebral bodies form cartilaginous joints These joints limit the range of intervertebral motion Superior and inferior articular processes on adjoining vertebrae form facet/zygapophyseal joints These are synovial joints The size, shape and positioning of the articulating surfaces and the resulting joint planes depend on the vertebral region. The orientation of the articular surfaces determine the type and range of movements possible at each region. Vertebral Column Ligaments Posterior longitudinal ligament Intertransverse Ligaments are dense fibrous connective tissue ligaments They attach bone to bone Serve to limit joint movement Anterior longitudinal ligament – limits extension Posterior longitudinal ligament – limits flexion Intertransverse ligaments – limits lateral flexion Supraspinous ligaments – limits flexion Supraspinous ligament Anterior longitudinal ligament Vertebral Column (Spinal) Movements Recall: Muscles and Movement Origin Muscle must cross a joint to make a movement Muscle attachment sites are: Insertion Origin: Muscle beginning - does not move during contraction Usually the proximal end of a bone/joint Insertion: Muscle end - is pulled towards the origin during contraction Usually the distal end of a bone/joint Recall: Muscles and Movement Origin Muscle must cross a joint to make a movement Muscle attachment sites are: Origin: Muscle beginning - does not move during contraction Insertion Usually the proximal end of a bone/joint Insertion: Muscle end - is pulled towards the origin during contraction Usually the distal end of a bone/joint Flexion of the Vertebral Column Flexion occurs in the sagittal plane Muscles involved in flexion are positioned anterior to intervertebral joints: Rectus abdominus Extension of the Vertebral Column Extension occurs in the sagittal plane Muscles involved in extension are positioned posterior to intervertebral joints: Erector Spinae muscle group Rotation of the Vertebral Column Rotation occurs in the transverse/horizontal plane Muscles involved in rotation are positioned in an oblique direction: Sternocleidomastoid Internal and external obliques Lateral Flexion of the Vertebral Column Lateral flexion occurs in the coronal/frontal plane Muscles involved in lateral flexion are positioned lateral to the intervertebral joint: Erector Spinae muscle group Internal and external obliques Development of the Vertebral Column Embryonic Development During the third week of embryonic development, three distinct germ layers develop and form different structures of the body: Endoderm: Gives rise to epithelial linings and glands of digestive & respiratory systems, abdominal organs & urinary bladder Mesoderm: Gives rise to all connective tissue, muscular tissue, the dermis, the vascular system and the urogenital system (except the urinary bladder) Ectoderm: Gives rise to epidermis, nails, hair and nervous tissue Differentiation of the Mesoderm Recall that the mesoderm gives rise to all connective tissue, muscular tissue, the dermis, the vascular system and the urogenital system (except the urinary bladder) During embryonic development, there are modifications that occur to the mesoderm on either side of the notochord These modifications are called somites (number of somite pairs increases as embryo develops (lengthens)) Differentiation of Somites Somites differentiate into three possible structures: Sclerotome 1. Sclerotome (forms the vertebrae and ribs) 2. Dermatome (forms dermis of the skin) 3. Myotome (forms skeletal muscles of the neck, trunk & limbs) that further differentiates into: Epimere: muscles on the posterior/dorsal surface Hypomere: muscles on the anterior/ventral surface Innervation & Blood Supply of the Trunk Recall: Structure of Spinal Nerves Anterior/ventral roots contain motor neurons (motor info out) and posterior/dorsal roots contain sensory neurons (sensory info in) Spinal nerves form where the anterior and posterior roots come together as they exit the spinal cord (through the intervertebral foramina) Spinal nerves branch into anterior and posterior rami (pl.) Trunk region supplied by rami from spinal nerves T1-T12 Recall: Anterior and Posterior Rami Posterior ramus supplies the structures of the back Anterior ramus supplies the entire anterior surface of the body AND the limbs (hence the larger diameter) Any given ramus may have the following branches: Muscular branch- Innervating muscle Cutaneous branch- Innervating skin Articular branch- Innervating the joint Vascular branch- Innervating blood vessels Recall: Hierarchy of Blood Vessels Arteries Arterioles Capillaries Venules Veins Arterial Supply of the Trunk The major artery supplying the trunk (thoracic and abdominopelvic regions) is the aorta The aorta has four distinct sections: 1. Ascending aorta 2. Aortic arch 3. Thoracic (descending) aorta: Spans from approx. T4-T12 vertebral level Has many branches to supply structures of the thoracic region Passes through the diaphragm (aortic hiatus) 4. Abdominal aorta Continuation of thoracic aorta and spans from approx. T12- L4 vertebral level Uni of Florida Health, 2023 Has many branches to supply structures of the abdominopelvic region Venous Drainage of the Trunk Recall: Wherever there is an artery, you will find a vein The major veins that drain the trunk (thoracic and abdominopelvic regions) are the superior and inferior vena cava Superior vena cava: Located in the thoracic region Has many branches that allow it to drain deoxygenated from the upper half of the body (head, neck, upper limbs and upper thoracic) back to the heart Inferior vena cava: Located in the abdominopelvic region Has many branches that allow it to drain deoxygenated from the lower half of the body (lower thoracic, abdominopelvic and lower limbs) back to the heart  Speech Pathology Clinical Connection Occupational Physiotherapy Therapy Kyphosis & Lordosis (Not Examinable) What is Kyphosis? What is Lordosis? Kyphosis An increase in the thoracic curve of the vertebral column Produces a ‘hunchback’ appearance In the elderly, degeneration of intervertebral discs leads to kyphosis Common in females with advanced osteoporosis Lordosis An increase in the lumbar curve of the vertebral column Sometimes referred to as ‘hollow back’ May result from increased weight of the abdomen: Pregnancy Extreme obesity Poor posture Osteoporosis Treatment of Abnormal Vertebral Curves Usually start conservatively with stretching and strengthening exercises and other lifestyle changes Bracing Serious cases can progress to surgical intervention: Pedicle subtraction osteotomy – removal of a wedge of bone from the spinal column to reduce curvature Vertebral column resection – removal of one or more vertebrae from the spine for proper repositioning and straightening Spinal correction – Rods, plates or screws used to correct the spine’s alignment Spinal fusion – Fusion of multiple vertebrae to stabilise and straighten the spine. Turn to your neighbour and discuss why such a patient may need the assistance of an allied health professional from your discipline CRICOS 00123M