BSC 2085L lesson 5

Main parts

skull, vertebral column, and bony thorax

vertebral column consists of

-24 vertebrae separated by intervertebral discs composed of fibrocartilage

-sacrum

-coccyx

C1

atlas- lacks body and spinous process, allows head to nod

C2

axis- has dens (odontoid process) for head rotation

C1-7 distinguishing features

- triangular vertebral foramen

- transverse processes contain foramen for vertebral arteries traveling to brain

- C7 (vertebra prominens) landmark for counting vertebra

Thoracic vertebrae: T1-12 distinguishing features 

- heart shaped body

- small articulating surfaces/costal facets articulate with head of rib

- round vertebral foramen

- transverse costal facets articulate with rib tubercles 

lumbar vertebrae: L1-5 distinguishing features

– block-like body & short thick spinous process
– superior articular process pointing posteromedial
– inferior articular process pointing anterolateral
– spinal cord ends at superior area of L2
– Spinal/lumbar ‘tap’ performed between L3 and L4 or L4 and L5 to minimize injury to spinal cord

intervertebral foramen

exists between inferior notch of a superior vertebra and superior notch of an inferior vertebra for nerves to enter/exit spinal cord

sacrum

formed by fusion of 5 bones

sacral promontory

anterior border of S1

median sacral crest

remnant of fused spinal processes

ala

formed by fusion of transverse processes

transverse ridges

site of vertebral fusion

anterior/posterior sacral foramina

passage for blood vessels and nerves

coccyx

tailbone- formed by fusion of 3-5 irregularly shaped vertebrae 

attached to sacrum by ligaments

scoliosis 

kyphosis

excessive posterior thoracic curvature

lordosis

excessive lumbar curvature

bony thorax composed of

- sternum

- ribs (12 pairs)

- thoracic vertebrae: anchoring sites for ribs