ROP Sports Medicine BONES OF THE SPINE Introductory

ROP Sports Medicine: BONES OF THE SPINE

Introductory Information The spine is a stack of 33 bones called vertebra held together by ligaments and muscles. p Between each vertebra, there is a fibrocartilage disc, disc which is made mostly of protein and water. p

The bones are divided into 5 sections: n n n Cervical Spine = the most superior group, a. k. a. the neck; contains 7 vertebrae Thoracic Spine = the chest; contains 12 vertebrae Lumbar Spine = the low-back; contains 5 vertebrae Sacral Spine = Contains 5 vertebrae which are fused together into one structure called the sacrum. Coccygeal Spine = Contains 4 vertebrae which are fused together into one structure called the coccyx (that’s your tailbone)

Spinal Curvatures: n When viewed laterally, the spine has 4 curvatures: p p An anterior, or convex, curve called a lordosis is seen in the cervical and lumbar spine. A posterior, or concave, curve called a kyphosis is seen in the thoracic and sacro-coccygeal spine.

Spinal Curvatures: n What can cause an increase or decrease in the spinal curvature? p. It depends on shifts in the body’s center of gravity (e. g. with pregnancy, weight gain, weight loss, or trauma).

p Function of the spinal column = to maintain the body in an upright position with the brain located over the body’s center of gravity.

Bones of the Spinal Column p All vertebrae have: 1. A vertebral body 2. 2 Transverse Processes (TP)= lateral bony projections that serve as a source for ligamentous and muscular attachment. 3. Spinous Process (SP) = a posterior bony process that serves as a source of ligamentous and muscular attachment. 4. Vertebral Foramen = where the spinal cord and nerve roots pass.

Bones of the Spinal Column 5. Superior and inferior articulating facets = where the vertebra articulates with the vertebrae above and below. 6. Lamina = forms the posterior portion of the vertebral foramen. 7. Pedicles = form the lateral sides of the vertebral foramen. 8. Intervertebral Foramen (IVF) = located between each vertebra and allows the nerve branches from the spine to pass through. 9. Pars Interarticularis = the bony area between the superior and inferior articulating facets

Bones of the Spinal Column

Cervical Vertebrae: p p p How many cervical vertebrae are there? n There are 7, numbered from top to bottom (C 1 -C 7). What do all cervical vertebrae have? 1. A bifid (split) spinous process 2. A transverse process foramen What passes through the foramen? n The blood vessels for the cervical spine (particularly the Vertebral Artery)

Cervical Vertebrae: p Atlas = the 1 st cervical vertebra n Has no vertebral body n Has 2 large articular facets that provide a surface where the skull and the spinal column articulate.

Cervical Vertebrae: p Axis = the 2 nd cervical vertebra n The atlas slides over the axis, and rests on 2 large superior articulating surfaces. n Dens (a. k. a. Odontoid Process) = a large bony process between the 2 articular surfaces of the axis. n C 7 = has a very long spinous process (most easily palpated).

Thoracic Vertebrae: p p How many thoracic vertebrae are there? n There are 12. What is special about the SP’s of Thoracic Vertebrae? n Thoracic vertebrae have longer and more vertically inclined spinous processes. p Costal Facets = articulating surfaces on the anterior lateral aspects of the transverse processes and the superior and inferior portions of the posterior lateral aspects of the vertebral bodies that provide the articulation for the 12 pairs of ribs with the 12 thoracic vertebrae.

Lumbar Vertebrae: p p p How many lumbar vertebrae are there? n There are 5. What is special about them? n They are the largest vertebrae. What do lumbar vertebrae not have? n They have no transverse process foramen or costal facets on their bodies.

Sacral Vertebrae: n n n The 5 sacral vertebrae are separate at birth. The bones eventually fuse together to form a large triangular-shaped bone known as the sacrum The 2 large articular surfaces formed on the lateral aspects of the sacrum are where the spinal column articulates with the bones of the pelvis

Coccygeal Spine: p p The 4 coccygeal vertebrae are separate at birth. The bones eventually fuse together to form the coccyx, coccyx a. k. a. your tailbone

The Intervertebral Disc (IVD) The IVD is a cartilaginous disc made of mostly water and protein. n There is one disc between each pair of vertebrae (except for C 1 and the skull, and any of the sacral or coccygeal vertebrae). n Purpose: 1. A spacer to allow nerve roots to pass from the spinal column to other body structures. 2. Shock absorption for the spinal column. n Parts of the Disc: n p p Nucleus Pulposus = the inner portion of the disc; consists of soft, pulpy, elastic tissue. Annulus Fibrosis = the other portion of the disc; cosists of fibrous tissue.

The Intervertebral Disc (IVD) p Parts of the Disc: n n Nucleus Pulposus = the inner portion of the disc; consists of soft, pulpy, elastic tissue. Annulus Fibrosis = the other portion of the disc; consists of fibrous tissue.