Download B. The Vertebral Column (Spine)

B. The Vertebral Column (Spine)
*Vertebral column extends from skull to pelvis
1.
Vertebrae: irregular shaped bones that
make up the spine
-24 single vertebrae: 7 cervical, 12
thoracic, 5 lumbar
-plus 1 sacrum (5 fused vertebrae) & 1
coccyx (4 fused vertebrae)
2. Intervertebral discs: pads of flexible
fibrocartilage that separate the single
vertebrae; cushion vertebrae & absorb
shocks
Side note: herniated discs are “slipped”
discs that protrude outward from normal
position due to drying of discs &
weakened ligaments or caused by
exceptional twisting forces
Figure 5.14
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
B. Vertebral Column (Spine)
3. S-shaped curvature (refer to fig. 5.14 &
5.15)
-normal skeleton has an S-shape
-cervical region—anteriorly curved (concave)
-thoracic region—posteriorly curved (convex)
-lumbar region—anteriorly curved
-sacral & coccygeal regions—posteriorly
curved
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
B. Vertebral Column (spine)
3. S-shaped curvature
continued
a. scoliosis: abnormal
lateral curvature
b. kyphosis: hunchback;
abnormal posterior
curvature of spine mostly in
upper thoracic region
c. lordosis: swayback;
abnormal anterior curvature
of spine mostly in lumbar
region
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Fig 5.15
B. Vertebral Column (spine)
4. Similar features of typical vertebrae
a. body or centrum: disclike, weight-bearing part of
vertebra facing anteriorly in vertebral column
b. vertebral arch: arch formed from the joining of all
posterior extensions, the laminae and pedicles, from
the vertebral body
i. laminae—extend from transverse processes to
spinous process
ii. pedicles—extend from body to transverse
processes
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
B. Vertebral Column
c. vertebral foramen: canal through vertebra
that spinal cord passes through
d. transverse process: 2 lateral projections from
vertebral arch
e. spinous process: single posterior projection
f. superior/inferior articular processes (facets):
paired projections lateral to vertebral
foramen; allow vertebra to form joints with
adjacent vertebrae
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Structure of a Typical Vertebrae
Figure 5.16
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings