Lecture 11 - The axial skeleton Flashcards
what is the benefit of having a higher ratio of spongy:compact bone in vertebrae?
the spongy bone is more compression resistant
- makes bones lighter also
if spongy bone is more beneficial to the vertebrae, why do we need compact bone?
because they work together.
- spongy bone can deform, but with a compact outer layer, it won’t.
what are the 7 types of bones?
- long
- short
- Sutural
- pneumatized
- flat
- irregular bones
- sesamoid bones
what are the features of sutural bones?
used as a ‘glue’ for two flat bones of the skull, and normally fuse/disappear with age
what are the features of sesamoid bones?
usually appear with age and are used to prevent compressive loads/strain on tendons and other structures such as femur
what are pneumatized bones?
bones with air pockets in them
what are the features of irregular bones?
have bits that stick out -> portrusions that are used for attachment of muscles (tendons) and ligaments
what are short bones?
usually cuboidal bones, such as the carpals in the hand
what kinds of areas are elevations (e.g tuberosities) usually found?
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.
how can the number of bones change with age?
fusion of bones means less number of bones, while supernumerary/accessory bones such as sesamoid bones increases the number
what is the main purpose of the facial bones?
- sensory (incl. hearing and sight)
- communication
- breathing
- eating
what is the main purpose of the cranial bones?
to protect the brain.
what are the three types of excessive spine curvature and in who do we normally see it?
- scoliosis (lateral)
- Kyphosis (saggital, primarily thoracic, old people)
- Lordosis (saggital, primariy lumbar to account for change in centre of gravity such as pregnancy)
the thoracic spinal region naturally has an anterior _______ curve
concave
the lumbar spinal region naturally has an anterior _______ curve
convex
how many total bones in the vertebral column and how many are mobile?
33 total, 24 mobile
(some are fused)
what is the primary function of the cervical vertebrae
support the head
what is the primary function of the thoracic vertebrae
protection
what is the primary function of the lumbar vertebrae
stability
what is the primary function of the coccyx
none lol kinda lowkey useless
what is the function of the vertebral arch
to support and protect the spinal cord
what are the superior and inferior articular processes?
projections with articular facets on the end, which contain articular cartilage on the surfaces
form the zygapophysial joints
help control and limit movement
what is the vertebral foramen?
the space where the spinal cord passes through
what are transverse processes?
poke out laterally and are used for tendon and ligament attachment
- articulate with ribs for breathing in the thoracic segment
what are the spinous processes?
used as an attachment point for muscles and tendons which move the spine and maintain posture
what are the pedicles?
connects the vertebral body to the transverse processes
forms the lateral sides of the vertebral foramen
what are the laminae?
- 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
which part of your back makes the crack sound and why?
the zygophyseal joints snapping back into place
what structures form the intervertebral foramen?
the superior and inferiors articular processes and the pedicles
- and somewhat the vertebral body
what is the function of the intervertebral foramen?
to allow the peripheral nerves to exit the spinal cord
describe the cervical vertebrae
- small body, larger, triangular vertebral foramen (thick spinal cord)
- foramen transversarium to house the vertebral arteries and veins and support rotation of the head
- bifid spinous process
what is the feature of the C7 vertebrae?
has a very long spinous process
- can feel it on back of neck
describe the thoracic vertebrae
- heart shaped body
- long sloping spinous process
- long transverse processes
- costal facets
what do the costal facets do?
join to the ribs and allow breathing movement
- stabilise the rib cage
describe the lumbar vertebrae
- large vertebral body
- no ribs, no costal facets
for supporting the body
