Axial Skeleton (vertebrae, ribs)

Question 1

Number and types of vertebrae

Answer 1

26 total
- 7 cervical
- 12 thoracic
- 5 lumbar
- 1 sacral (5 fused)
- 1 coccygeal (4 fused)

Question 2

name 4 curves in vertebral column

Answer 2

cervical
thoracic
lumbar
sacral

Question 3

how do spinal curves develop?

Answer 3

• starts as 1 concave curve
• 3 months old: cervical curve
• when baby can stand, lumbar curve develops

Question 4

name general features and 7 processes of a vertebrae

Answer 4

BODY
- anterior, largest part
VERTEBRAL ARCH
- LAMINA+PEDICLE
- connect spinous process to body
VERTEBRAL FORAMEN
- hole in centre, forms vertebral canal

1xSPINOUS PROCESS
- posterior process
2x TRANSVERSE PROCESS
- big lateral process
2x SUPERIOR ARTICULAR PROCESS
- articular process
- sticks upward
- contains SUPERIOR ARTICULAR FACET that forms joint
- joins with an 2x INFERIOR ARTICULAR PROCESS

Question 5

features specific to thoracic vertebrae

Answer 5

articulates with ribs
- ARTICULAR FACET for tubercle of rib (located on transverse process)
- SUPERIOR DEMIFACET (connects to head of the rib)

Question 6

openings between vertebrae where spinal nerves exit spinal cord

Answer 6

intervertebral foramina

Question 7

characteristics of C1

Answer 7

“atlas”
- no vertebral body
- no spinous process
- large vertebral foramen
- large superior articular facets that form joint with occipital bone
- facet for dens (forms join with C2)

Question 8

characteristics of C2

Answer 8

• small body
• small spinous process
• smaller veritbral foramen
• flat articular facets (allows for large degrees of movement)
• DENS on anterior side (trailer hitch! swivle)

Question 9

characteristics of cervical vertebrae past axis

Answer 9

• spinous process (exept C7) bifid (2 heads)
• flat articular facets

Question 10

pros and cons of flat articular facets, where do you find them?

Answer 10

• cervical vertebrae (atlas onward)
• allow for wide range of movement
• if too much pressure applied because nothing’s really holding them together

Question 11

characteristics of lumbar vertebrae

Answer 11

• more body, thicker bone
• shorter, thicker spinous processes
• superior articular facets point medially, inferior point laterally

Question 12

characteristics of sacrum/coccyx

Answer 12

Sacrum
- sacral canal
- superior articular facets (1 pair)
- median sacral crest (5 fused vertebrae)
- posterior sacral foramen
- SACREAL HIATUS (5th vertebrae missing spinous process)

Coccyx

Question 13

when do sacral and coccygeal vertebrae fuse

Answer 13

Sacrum
age 16-18
don’t finish until age 30

Coccyx
age 20-30

Question 14

what are intervertebral disks made of?

Answer 14

fibrocartilage

Question 15

purposes of intervertebral disks

Answer 15

• provide support
• absorb vertical shock
• permits movement

Question 16

components of vertebra disks

Answer 16

ANNULUS FIBROSUS
- outer fibrocartilage
NUCLEUS PULPOSUS
- inner jelly pulp

Question 17

herniated disk

Answer 17

• tear of cartilage in annulus fibrosis of disk that causes leak of nucleus pulposus
• compresses spinal nerve
• happens posteriorly because of body’s weight distribution
• hard to heal because fibrocartilage avascular

Question 18

thoracic cage structure function

Answer 18

structure (semi-rigid)
- thoracic vertebrae
- 12 ribs
- costal cartilages
- sternum

function
- protects vital organs
- semi rigid to allow for movement of lungs and torso

Question 19

types of ribs

Answer 19

12 total
7 true (VERTEBROSTERNAL)
5 false (3 VERTEBROCHONDRAL, 2 floating/VERTEBRAL)

Question 20

components of sternum

Answer 20

Manubrium
- sternal angle
- jugular (suprasternal) notch
- joint with clavical
Body
Xiphoid process

Question 21

when does xiphoid process ossify

Answer 21

age 40