week 3: axial skeleton- spine, sternum, ribs

vertebral column

• protects spinal cord

• supports trunk/transmits weight to lower extremities

• attachments for ribs and muscles of neck/back

how many vertebrae? (fused)

24

normal S curve

for balance and support during movement and weight distribution

lumbar region

• carries most weight

• moves the most

• most common site of injuredy 85%

atlas

C1, holds the head

axis

C2, world sits on axis

fovea dentis

facet on atlas C1 for the dens/odontoid process of C2

dens/odontoid process

toothlike protrusion on axis C2

sacrum

5 fused bones under the vertebrae

ala

wings of the sacrum

sacral hiatus

end hold of the sacrum

intervertebral disc

• absorbs shock

• load distribution

• spacer between vertebrae

• 25% of spinal column height

• flatten during day so shorter at night

nucleus pulposus

inner jelly of the intervertebral disc

annulus fibrosus

outer ring of the intervertebral disc

anterior longitudinal ligament (ALL)

• limits posterior (going back) motion and excessive extension

• connects to anterior surface of vertebral bodies and intervertebral discs (outside)

posterior longitudinal ligament

• limits anterior (going forward) motion and excessive flexion

• connects to posterior vertebral bodies along spinal cord (inside hole)

kyphosis

posterior curve of thoracic spine and sacrum

lordosis

anterior curve of lumbar and cervical spine

scoliosis

lateral curve typically on thoracic spine

degenerated disc

• disease caused by wear and tear

• causes weakness, numbness, and shooting pain

bulging disc

disc forms bulge that pushes on nerves

herniated disc

bulging disc ruptures and nucleus pulposus is out

thinning disc

wal of disc becomes weak as disc ages nad loses water in center

disc degeneration with osteophyte formation

bony outgrowth because of degenerated cartilage (bone spur)

laminectomy

removing part of the lamina of the vertebra to make room for bulging/herniated disc that is pushing on nerves

disectomy

removing part of bulging/herniated disc that is pushing on nerves

true ribs

• ribs #1-7

• one to one connection with sternum

• increase in length as go down

false ribs

• ribs #8-12

• share connection to sternum

• decrease in length as go down

floating ribs

• false ribs #11 and 12

• don’t connect anteriorly to sternum

angle of rib

region of greatest curve beyond the tubercle of the rib

tubercle of rib

bump closer to the side of the vertebrae (always facing the top)

neck of the rib

constricted portion of the rib beyond the head

shaft of rib

sharper side on bottom, smoother side on top

manubrium

top portion of sternum that articulates with clavicle and first 2 ribs

jugular notch

notch at top of the manubrium

clavicular notch

notches on the top sides of the manubrium

body of sternum

middle part of sternum that has facets for attachment of ribs

xiphoid process

bottom part of sternum that CPR should be avoided on

xiphosternal joint

connection of the body of sternum to the xiphoid process