1. Lecture 11--Vertebral Column 1 (3/3/14 8:00 AM)

2. Learning Objectives

3. At the end of this lecture the students should be able to: Enumerate divisions of vertebral column. Name and identify parts of typical vertebra. Explain how cervical, thoracic and lumbar vertebrae differ and be able to identify all parts. Explain normal curves of the spine. Enlist muscles of the back with their arrangement. Identify clinical application.

4. Reference: Clinical anatomy by regions 9 th edition (Pages 683 – 695).

6. Divisions of vertebral column The vertebral column is composed of 33 vertebrae: – Cervical=7 – Thoracic=12 – Lumbar=5 – Sacral=5 (fused to form the sacrum) – Coccygeal=4 (the lower 3 are commonly fused). As it is segmented and made up of vertebrae, joints, and pads of fibrocartilage called intervertebral discs, it is a flexible structure. The intervertebral discs form about one quarter the length of the column.

8. Parts of a typical vertebra A typical vertebra consists of: – A rounded body--anteriorly – A vertebral arch--posteriorly. These enclose a space called the vertebral foramen, through which run the spinal cord and its coverings. The vertebral arch consists of: – A pair of cylindrical pedicles, which form the sides of the arch – A pair of flattened laminae, which complete the arch posteriorly.

9. The vertebral arch gives rise to seven processes: – Spinous process=1 – Transverse processes=2 – Articular processes=4 Superior=2 Inferior=2 The spinous process, or spine, is directed posteriorly from the junction of the two laminae. The transverse processes are directed laterally from the junction of the laminae and pedicles.

10. The articular processes: – Vertically arranged – Arise from the junction of the laminae and the pedicles, – Covered with hyaline cartilage. The two superior articular processes of one vertebral arch articulate with the two inferior ones of the arch above, forming two synovial joints. The pedicles are notched on their superior and inferior borders, forming the notches there. On each side, the superior notch of one vertebra and the inferior notch of an adjacent vertebra together form an intervertebral foramen that transmit the spinal nerves and blood vessels.

17. Points of differentiation between vertebrae of different regions

18. Cervical vertebraThoracicLumbar 1.Body of the vertebraSmall, broad from side to side Medium, heart shaped Large, kidney shaped 2. PediclesStrong, directed backwards 3.LaminaeShort vertically 4.Vertebral foramenlarge, triangularSmall, CircularTriangular 5.Transverse processPerforatedBears a facet for tubercle of rib Long and slender 6.Spinous processSmall and bifidLong, inclined downwards Short, flat, quadrangular face posteriorly 7.Costal facetsNoOn the side of body for rib No 8.Sup art process-- facet Facing posteriorly and superiorly facing posteriorly and laterally Face medially 9.Inf art process--facetFacing anteriorly and inferiorly facing anteriorly and medially Face laterally

19. Curves of the vertebral Column Curves in sagittal plane: In the adult in the standing position, the vertebral column exhibits the following regional curves: cervical, posterior concavity; thoracic, posterior convexity; lumbar, posterior concavity; sacral, posterior convexity. Curves in coronal plane: Right-handed persons will often have a slight right-sided thoracic convexity. Slight compensatory curves are always present superior and inferior to such a curvature.

21. Muscles of the back The muscles of the back may be divided into three groups: – The superficial muscles connected with the shoulder girdle. – The intermediate muscles involved with movements of the thoracic cage. – The deep muscles or postvertebral muscles belonging to the vertebral column.

22. The superficial muscles(U.Limb→V. column): – Trapezius – Latissimus dorsi – Levator scapulae – Rhomboid minor and major The intermediate muscles: – External intercostal (11) – Internal intercostal (11) – Innermost intercostal – Diaphragm – Levatores costarum (12) – Serratus posterior superior and inferior

23. Deep muscles Superficial Vertically Running Muscles – Erector spinae iliocostalis longissimus spinalis Intermediate Oblique Running Muscles – Transversospinalis Semispinalis multifidus Rotatores Deepest Muscles – Interspinales – Intertransversarii

26. Abnormal Curves of the Vertebral Column Kyphosis: an exaggeration in the sagittal curvature present in the thoracic part of the vertebral column. Lordosis: is an exaggeration in the sagittal curvature present in the lumbar region Scoliosis: is a lateral deviation of the vertebral column, commonly found in the thoracic region Dislocations of vertebral column Fractures of vertebral column