MSK - The Back - Anatomy Lecture Notes PDF

MSK – The Back Bones, Joints, Intrinsic muscles & Spinal cord General Objective To understand the anatomical basis of posture and movement, and the...

MSK – The Back Bones, Joints, Intrinsic muscles & Spinal cord General Objective To understand the anatomical basis of posture and movement, and the functional significance of the vertebral column. Specific Objectives 1. Vertebral column and vertebrae 2. Joints of the vertebral column 3. Deep (intrinsic) muscles of the back 4. Spinal cord and spinal nerves Dr Karthik Harve & Dr Frank Voon Some illustrations in this for the zoom lecture are from Netters and 2015 Pearson Education, Inc. 20 January 2025  Skull The It supports the weight Axial of the human body Skeleton above the pelvis, and maintains posture. Axial skeleton Skull Sternum It enables movement Vertebral column with its joints and Ribcage Ribcage muscles. Sternum It protects the spinal cord enclosed within The vertebral the spinal canal column forms formed by the the central axis vertebral foramina. of the body. 2015 Pearson Education, Inc. Vertebral column  Skull The vertebral Occipital bone 8 cranial column 14 facial bones C1 - C7 T1 - T12 Cervical Ribcage 12 ribs Thoracic L1 - L5 Sacrum S1 - S5 Lumbar Coccyx 2015 Pearson Education, Inc.  C1 – C7 C1 C1 – Atlas Vertebrae C2 C2 – Axis C3 C4 T1 – T12 C5 C6 C7 C7 – Vertebra T1 prominens L1 – L5 T2 S1 – S5 Coccyx  Brain 7 cervical vertebrae Spinal 8 cervical nerves cord C1 C1 C2 C2 C3 Spinal C4 C4 nerves C5 C5 C6 C6 Intervertebral C7 C7 foramina T1 T2 T1 Cauda T3 T2 equina T4 T3  Brain Skull Foramen magnum C6 End of larynx & pharynx Trachea & esophagus begin T4 Superior mediastinum Inferior mediastinum The spinal cord Vertebral ends at the column (spine) level between L1 End of spinal cord L1 and L2 L2 vertebrae S3 Level of pelvic diaphragm  Cauda equina Dorsal sacral foramina Dorsal root ganglion for dorsal rami of sacral nerves Posterior aspect L1 L2 Cauda equina The cauda equina is located in the subarachnoid space.  Primary Secondary curvatures curvatures Cervical curve Thoracic curve Secondary curvatures are formed after birth. The primary (lifting the neck curvatures develop & walking) during gestation. Lumbar curve Sacral curve  In medical communication Curves of the vertebral column Scoliosis refers to an abnormal increase in lateral curvature of the spine (vertebral column). Kyphosis refers to an abnormal increase in posterior curvature of the spine affecting the thoracic vertebra. Lordosis refers to an abnormal increase in anterior curvature of the spine affecting the cervical and lumbar vertebrae. Parts of a vertebra Vertebral Superior Spinal notch articular cord facet Vertebral Spinous process Body foramen Pedicle Superior Transverse process articular facet Superior aspect Parts of a vertebra Superior articular facet Lamina Transverse process Body Lateral aspect Inferior articular facet Vertebral notch  Cervical vertebra Transverse foramen (for vertebral artery) No costal facets Vertebral artery * * Superior aspect  Axis Facets for atlanto-axial joints Dens Foramen Body transversarium Spinous process The axis (C2 vertebra) has transverse foramina, a body, an odontoid process (dens) and spinous process.  The axis (C2 vertebra) has Atlas and Axis transverse foramina, a body, an odontoid process (dens) The atlas (C1 vertebra) and spinous process. has transverse foramina but no body, no dens dens (odontoid process) & no spinous process. facets for atlanto-occipital joints Axis Typical cervical vertebra Atlas C3 – C7  Joints of the vertebral column The atlanto-axial joint between C1 (atlas) and C2 (axis) vertebrae. enables rotation of the head. The atlanto-occipital joint between the C1 (atlas) and the occipital bone of the skull enables extension, flexion and lateral flexion of the head. Atlas Axis C3 Atlas C4  4th rib Costotransverse joint Tubercle of the rib The costotransverse joint connects the tubercle of a Costovertebral joint rib with the transverse (Head of the rib) process of a thoracic vertebra. The costovertebral joint is Posterior aspect Superior aspect the articulation between the head of a rib with the body of a thoracic vertebra. 2015 Pearson Education, Inc. 4th rib costal groove  Lumbar Transverse process vertebra No transverse foramina No costal facets Spinous Body process Superior aspect Spinous process Mamillary process The multifidus muscle attaches to the mammillary process. Anterior longitudinal ligament Ligamentum flavum Intervertebral Body foramen Intervertebral disc Interspinous ligament Lamina Body Spinous process Supraspinous ligament Posterior longitudinal ligament Facet joints Intervertebral disc Facet (zygapophyseal) joints The spaces between vertebrae are for the intervertebral discs  Sacrum Lumbosacral joint Ventral sacral foramina Dorsal sacral foramina Anterior aspect Posterior aspect  MSK – The Back Muscles & Nerves Deep (intrinsic) muscles of the back Iliocostalis lumborum Longissimus thoracis Multifidus Semispinalis capitis Intertransversarii Spinal cord and spinal nerves Sensory & motor components of a spinal nerve dorsal & ventral ramus dorsal & ventral root dorsal root ganglion Trapezius  Levator scapulae Trapezius Rhomboid minor Rhomboid major Deltoid Latissimus dorsi Serratus posterior superior Serratus posterior inferior Thoracolumbar fascia Semispinalis capitis Deep (intrinsic) muscles of the back Longissimus thoracis Innervation: Iliocostalis lumborum Dorsal rami Semispinalis capitis Deep (intrinsic) muscles of the back Rotatores Innervation: Dorsal rami Intertransversarii Multifidus  Meninges Dura mater Arachnoid mater Extradural space Pia mater Subdural space Erector spinae Subarachnoid space Spinal cord