VERTEBRAE & PECTORAL GRIDLE

INFANT= 33-34 BONES ADULT 26 BONES

Cervical vertebrae are the smallest of the vertebral types.  They contain transverse foramina, which allow passage of the vertebral arteries.  Atlas ‐ Cl modified to articulate with the occipital condyle, does not have a spinous process or body  Axis ‐ C2 ‐ acts as a pivot as in turning head from side to side, gesturing “no”. has a dens or odontoid process. The transverse ligament holds the dens in position against the atlas so that rotation can occur.  C7 is called the vertebrae prominens since it is easily palpable.  All the cervical spinous processes are bifid except C7.

modified to articulate with the occipital condyle, does not have a spinous process or body -CERVICAL VERTEBRAE

acts as a pivot as in turning head from side to side, gesturing “no”. has a dens or odontoid process. The transverse ligament holds the dens in position against the atlas so that rotation can occur -CERVICAL VERTEBRAE

called the vertebrae prominens since it is easily palpable.  All the cervical spinous processes are bifid except C7. -CERVICAL VERTEBRAE

Articulate with the ribs  These vertebrae are larger than cervical but smaller than lumbar vertebrae  Have elongated transverse processes for articulation with the ribs.  Have elongated downward pointing spinous processes

These are the largest and strongest individual vertebrae.  The spinous process points straight out rather than downward and in general are blunt, large processes  L4 and L5 allow the most motion.  Most disk injuries occur between L4‐L5 and L5‐S1, the area of the lumbosacral junction.  Since the lumbar vertebrae bear the most weight, a compression injury to the vertebrae or to the intervertebral discs most often occurs in this region.

5 bones fused into one unit. Usually fused by ages 25‐30.  Sacral nerves exit through the foramen while the filum terminale continues down through the sacral canal to anchor at the coccyx.  The sacrum is wedged between the iliac bones i.e. sacroiliac joint.

3‐5 bones (most commonly 4) fused into one unit.  Commonly called the tailbone.

Rounded weight bearing portion of the vertebra, faces anterior in the spinal column -STRUCTURE OF THE INDIVIDUAL VERTEBRAE

Large opening in the vertebra in which the spinal cord passes through -STRUCTURE OF INDIVIDUAL VERTEBRAE

Between the lamina and the body  Short bony pillars projecting posteriorly from the body.  Together with the lamina, form the vertebral arch -STRUCTURE OF INDIVIDUAL VERTEBRAE

Flattened plates and complete the vertebral arch posteriorly -STRUCTURE OF THE INDIVIDUAL VERTEBRAE

Two lateral projections, for muscle attachment -STRUCTURE OF INDIVIDUAL VERTEBRAE

Single projection, projects posteriorly.  Can be felt under skin as ‘backbone.’  For muscle attachment -STRUCTURE OF INDIVIDUAL VERTEBRAE

Observed only in cervical vertebrae  Provide passage for the vertebral artery and vein (going to and from the brain) -STRUCTURE OF INDIVIDUAL VERTEBRAE

has a site called the superior articulating facet that articulates with the inferior articulating facet of the vertebra superior to it -STRUCTURE OF INDIVIDUAL VERTEBRAE

has a site called the inferior articulating facet that articulates with the superior articulating facet of the vertebra inferior to it o The superior and inferior articulating facets join together (articulate) and create the intervertebral foreman in which the spinal pass through. You can see this on the models in the lab -STRUCTURE OF INDIVIDUAL VERTEBRAE

Fibrocartilaginous discs between two vertebrae  It is essentially a fluid, malleable, cushion between vertebrae  Not present between atlas and axis Not present between the sacral and coccygeal bones  ¼ length of vertebral column above the sacrum -STRUCTURE OF INDIVIDUAL VERTEBRAE

The ribs have heads with 2 facets for articulating with the thoracic vertebrae. 2. 7 pairs of true ribs ‐ attached by costal cartilage to the sternum 3. 3 pairs of false ribs ‐ attached by costal cartilage to costal cartilage of the 7th rib 4. 2 pairs of floating ribs ‐ the inferior 2 pairs of ribs. Do not attach anteriorly. 6. The space between the ribscan be increased during surgery by rib spreaders since the ribs and the costal cartilage are somewhat flexible. If more space is required, the cartilages are cut against the sternum and the entire sternum can be folded out of the way. Once repositioned, the cartilages are reunited by scar tissue and the ribs heal quite quickly. 8. The 3rd to the 7th ribs are fractured more frequently since they are more exposed. 9. If a rib is fractured and makes a hole into the pleural cavity, it causes a pneumothorax

between the ribs and filled with intercostal muscles (external and internal intercostals), intercostal nerves go to these muscles which are involved with respiration.

MEANS RIBS

The sternum, commonly referred to as the breastbone, is three bones fused together into one flat bone. The sternum is attached to the first seven pairs of ribs via costal cartilage.

ON THE MANUBRIUM -STERNUM