Vertebral Column Anatomy PDF

VERTEBRAL COLUMN 1 THORACIC VERTEBRAE INTRODUCTION  Second segment of the vertebral column  Located between the cervical and lumbar vertebrae  Consists of 12 vertebrae separated by intervertebral discs  Along with the sternum and ribs, the thoracic spine forms part of the thoraci...

VERTEBRAL COLUMN 1 THORACIC VERTEBRAE INTRODUCTION  Second segment of the vertebral column  Located between the cervical and lumbar vertebrae  Consists of 12 vertebrae separated by intervertebral discs  Along with the sternum and ribs, the thoracic spine forms part of the thoracic cage 2  CHARACTERISTIC FEATURES Have 4 features which distinguish them from other vertebrae  Heart-shaped vertebral body  Presence of demi-facets on the sides of each vertebral body that articulate with the heads of the ribs  Presence of costal facets on the transverse processes that articulate with the tubercles of ribs (T1-T10 only)  Long and inferiorly slant spinous processes that offer increased protection to the spinal cord 3 4 5 6  ATYPICAL THORACIC VERTEBRAE They display variation in size, location and number of costal facets  T1  Superior facet is not a demifacet  Only vertebra to articulate with the 1st rib  T10  Single pair of whole facet which articulate with 10th rib  The facets are located across both the vertebral body and pedicle  T11 and T12  Each have a single pair of entire costal facets which are located on the pedicles 7 8 9  JOINTS Costovertebral joint  Consists of the head of the rib articulating with:  Superior costal facet of the corresponding vertebra  Inferior costal facet of the superior vertebra  Intervertebral disc separating the two vertebrae Costotranverse joint  Formed by the articulation of transverse processes of a thoracic vertebra and the tubercle of adjacent rib  Absent in T11 and T12 10 11  LIGAMENTS Radiate ligament of head of rib  Fans outwards from head of rib to the bodies of the 2 vertebrae and intervertebral disc Costotransverse ligament  Connects the neck of the rib and transverse process Lateral costotransverse ligament  Extends from the transverse process to the tubercle of the rib Superior costotransverse ligament  Passes from the upper border of the neck of the rib to the transverse process of the vertebra superior to it 12 LUMBAR VERTEBRAE 13 INTRODUCTION  Third region of the vertebral column  Located in the lower back between the thoracic and sacral segments  Made of 5 distinct vertebrae which are the largest of the vertebral column  This supports the lumbar spine in its main function as a weight bearing structure 14  CHARACTERISTIC FEATURES  Large kidney-shaped vertebral bodies  Triangular vertebral foramen  Long and slender transverse process  Articular processes have nearly vertical facets  Short and broad spinous processes  The 5th lumbar vertebrae has a notably large vertebral body and transverse processes as it carries the weight of the entire upper body  They lack transverse foramina 15 16 LIGAMENTS  The lumbosacral joint (L5 & S1) is strengthened by the iliolumbar ligaments.  They are fan-like ligaments radiating from the transverse processes of L5 vertebrae to the ilia of the pelvis 17 18 19 SACRUM 20 INTRODUCTION  It is a large bone located at the terminal part of the vertebral canal  It forms the posterior aspect of the pelvis  It is remarkably thick and aids in supporting and transmitting the weight of the body  It is formed by the fusion of the 5 sacral vertebrae  It has an inverted triangular concave shape 21 22  INTRODUCTION CONT’D Consists of the following;  Base- articulates superiorly with the 5th lumbar vertebra and its associated intervertebral disc  Apex- abuts the coccyx inferiorly  Auricular surfaces- located laterally on the sacrum and articulates with the auricular surfaces of the ilium  Anterior and posterior surfaces- provide attachment to pelvic ligaments and muscles The central canal continues along the core of the sacrum and ends at the 4th sacral foramina, as the23 sacral hiatus  SURFACES Dorsal Surface  Coarse and rugged  Can be attributed to the fusion of the sacral vertebrae which give rise to 3 bony crests  The median sacral crest is formed by the fusion of the spinous processes of the first 3 sacral vertebrae and gives attachment to the supraspinous ligament  The intermediate sacral crests are formed by the fusion of the sacral articular processes and gives attachment to the posterior sacroiliac 24 ligaments  The articulating process of S1 articulates with inferior articulating process of L5  The articulating process of S5, the sacral cornu, articulates with the coccygeal cornu  The lateral sacral crests are formed by the fusion of the transverse processes of the sacral bones which gives attachment to posterior sacroiliac and sacrotuberous ligaments  The fusion is not complete, giving rise to the four pairs of posterior sacral foramina 25 26 27 SURFACES CONT’D Pelvic surface  Less remarkable than the dorsal surface  In the adult, it is marked by four transverse lines- the remnants of the fused intervertebral discs  Superiorly, there is an anterior projection of bone, the sacral promontory, that forms the posterior margin of the pelvic inlet 28 29 30 31  CLINICAL RELEVANCE Thoracic Kyphosis  An excessive curvature of the thoracic spine, causing the back to appear “hunched”  May occur for a number of reasons early in life  Poor posture  Abnormally wedge-shaped vertebrae  Fusion of vertebra during development  Various diseases can also lead to kyphosis in adults  The most common cause is osteoporosis which leaves the spine less able to support the weight 32 of the body 33 34  CLINICAL RELEVANCE CONT’D Excessive Lumbar Lordosis  An abnormal anterior curvature of the vertebral column in the lumbar region, characterised by anterior tilting of the pelvis  Women temporarily develop this condition in late pregnancy  In either sex, obesity can similarly cause lordosis due to increased weight of the abdomen 35 36  CLINICAL RELEVANCE CONT’D Scoliosis  A sideways curvature of the spine that occurs most often during growth spurt just before puberty  The cause of most scoliosis is unknown  About 3% of adolescents have scoliosis  Most cases are mild but some continue to get more severe as children grow  Girls have a much higher risk of the curve worsening and requiring treatment 37 38 39