Lecture 11 - The axial skeleton

Question 1

what is the benefit of having a higher ratio of spongy:compact bone in vertebrae?

Answer 1

the spongy bone is more compression resistant
- makes bones lighter also

Question 2

if spongy bone is more beneficial to the vertebrae, why do we need compact bone?

Answer 2

because they work together.
- spongy bone can deform, but with a compact outer layer, it won’t.

Question 3

what are the 7 types of bones?

Answer 3

• long
• short
• Sutural
• pneumatized
• flat
• irregular bones
• sesamoid bones

Question 4

what are the features of sutural bones?

Answer 4

used as a ‘glue’ for two flat bones of the skull, and normally fuse/disappear with age

Question 5

what are the features of sesamoid bones?

Answer 5

usually appear with age and are used to prevent compressive loads/strain on tendons and other structures such as femur

Question 6

what are pneumatized bones?

Answer 6

bones with air pockets in them

Question 7

what are the features of irregular bones?

Answer 7

have bits that stick out -> portrusions that are used for attachment of muscles (tendons) and ligaments
- vertbrae

Question 8

what are short bones?

Answer 8

usually cuboidal bones, such as the carpals in the hand

Question 9

what kinds of areas are elevations (e.g tuberosities) usually found?

Answer 9

where there is a force pulling on it, such as muscle attachments. more prominent elevations in bones seen on muscles that are used more often.

Question 10

how can the number of bones change with age?

Answer 10

fusion of bones means less number of bones, while supernumerary/accessory bones such as sesamoid bones increases the number

Question 11

what is the main purpose of the facial bones?

Answer 11

• sensory (incl. hearing and sight)
• communication
• breathing
• eating

Question 12

what is the main purpose of the cranial bones?

Answer 12

to protect the brain.

Question 13

what are the three types of excessive spine curvature and in who do we normally see it?

Answer 13

• scoliosis (lateral)
• Kyphosis (saggital, primarily thoracic, old people)
• Lordosis (saggital, primariy lumbar to account for change in centre of gravity such as pregnancy)

Question 14

the thoracic spinal region naturally has an anterior _______ curve

Answer 14

concave

Question 15

the lumbar spinal region naturally has an anterior _______ curve

Answer 15

convex

Question 16

how many total bones in the vertebral column and how many are mobile?

Answer 16

33 total, 24 mobile
(some are fused)

Question 17

what is the primary function of the cervical vertebrae

Answer 17

support the head

Question 18

what is the primary function of the thoracic vertebrae

Answer 18

protection

Question 19

what is the primary function of the lumbar vertebrae

Answer 19

stability

Question 20

what is the primary function of the coccyx

Answer 20

none lol kinda lowkey useless

Question 21

what is the function of the vertebral arch

Answer 21

to support and protect the spinal cord

Question 22

what are the superior and inferior articular processes?

Answer 22

projections with articular facets on the end, which contain articular cartilage on the surfaces
form the zygapophysial joints
help control and limit movement

Question 23

what is the vertebral foramen?

Answer 23

the space where the spinal cord passes through

Question 24

what are transverse processes?

Answer 24

poke out laterally and are used for tendon and ligament attachment
- articulate with ribs for breathing in the thoracic segment

Question 25

what are the spinous processes?

Answer 25

used as an attachment point for muscles and tendons which move the spine and maintain posture

Question 26

what are the pedicles?

Answer 26

connects the vertebral body to the transverse processes
forms the lateral sides of the vertebral foramen

Question 27

what are the laminae?

Answer 27

• Extend from the pedicles to the spinous process, forming the posterior wall of the vertebral foramen.
• Protect the spinal cord and provide attachment points for ligaments and muscles.
• fuse together

Question 28

which part of your back makes the crack sound and why?

Answer 28

the zygophyseal joints snapping back into place

Question 29

what structures form the intervertebral foramen?

Answer 29

the superior and inferiors articular processes and the pedicles
- and somewhat the vertebral body

Question 30

what is the function of the intervertebral foramen?

Answer 30

to allow the peripheral nerves to exit the spinal cord

Question 31

describe the cervical vertebrae

Answer 31

• small body, larger, triangular vertebral foramen (thick spinal cord)
• foramen transversarium to house the vertebral arteries and veins (determiner)
• oblique articular facets for rotation
• bifid spinous process

Question 32

what is the feature of the C7 vertebrae?

Answer 32

has a very long spinous process
- can feel it on back of neck

Question 33

describe the thoracic vertebrae

Answer 33

• heart shaped body
  -longer processes for muscle attachment
• costal facets (determiner)

Question 34

what do the costal facets do?

Answer 34

join to the ribs and allow breathing movement
- stabilise the rib cage

Question 35

describe the lumbar vertebrae

Answer 35

Bigger and buttier, for support. very limited movement here.

Question 36

how do we know which thoracic vertebrae number we are at?

Answer 36

look at the rib attached to the superior costal facet of the vertebrae you want to find the number of. The numbers are the same. e.g rib 4 attaches to the superior costal facet of thoracic vertebrae 4.

Question 37

why are we shorter at night than in the morning?

Answer 37

water squeezing out of out intervertebral discs as they are loaded throughout the day.