last minute anatomy revision Flashcards
what’s myelin
Myelin is a fatty white substance that surrounds the axon of some nerve cells, forming an
electrically insulating layer. It is essential for the proper functioning of the nervous system.
where does myelin come from
its secreted by schwann cells wrapped around the axons
what’s the endoneurium
The endoneurium is a layer of delicate connective tissue around the myelin sheath of each
nerve fibre
what surrounds fascicles
Each fascicle (bundle of fibres) lies within its own protective sheath called a perineurium.
what’s the epineurium
In sufficiently large nerves multiple fascicles, each with its blood supply and fatty tissue, may
be bundled within yet another sheath, the epineurium.
what surrounds individual axons?
endoneurium i think
what surrounds nerve fascicles?
perineurium
what surrounds a nerve?
epineurium
What’s a dermatome
A dermatome is an area of skin that is mainly supplied by afferent nerve fibres from the dorsal root of any given spinal nerve.
What type pf muscle is found in the diaphragm?
skeletal muscle- most of the time it is involuntary, but sometimes it is voluntary, so it’s skeletal
What happens to the shape of the diaphragm when it contracts?
flattens
What type of nerve cell lies in the dorsal root ganglion of a spinal nerve?
sensory/afferent
Through which foramina do spinal nerves exit the vertebral column?
intervertebral
Muscles in the same compartment (e.g., the anterior compartment of the forearm) share
what?
innervation
Sympathetic nerves are only found where
thoracic-lumbar region
what lies within the intervertebral foramen?
nerves, vessels and ligaments
what type of joint occurs between the bodies of adjacent vertebrae?
secondary cartilaginous/symphysis
(of fibrocartilage)
what joint occurs between articular processes of the vertebral column
plane synovial joint
zygapophysial (facet) joint
name for C7
vertebrae prominens
what distinguishes cervical vertebrae
bifid spinous process
transverse foramens
what distinguishes thoracic vertebrae
costal facets for ribs
heart shaped vertebral foramen
what’s special about c2
dens which articulates with c1
movement permitted in:
cervical
thoracic
lumbar
card not finished/checked
cervical=most.
flexion, extension, lateral flexion, and rotation:
thoracic=least. large rotational and lateral flexion movements, but limited flexion and extension.
lumbar=middly. significant flexion and extension, limited rotation
posterior vs anterior unilateral, what movement on the spine
both left and right sides contract together (bilaterally). A
how might limb muscles help contrinbute to movements of the vertebral column
if limb is immobilised eg during situps
how is intra-abdominal pressure increased
if flexor and extensor muscles of the abdomen contract simultaneously
lumbar puncture where
l3/4 or l4/5
does disc prolapse mean
herniation
What causes the intervertebral disc to prolapse or herniate
trauma, age
How does flexion of the vertebral column aid the performance of an LP?
It increases intervertebral space
At which vertebral level does the spinal cord terminate in: a. an adult, and b. a child
l1/2
l3/4
Which spinal nerves form the cauda equina, and from which spinal cord structure do they emerge
L2-S5
conus medullaris
where does the dural sac terminate
In an adult, the dural sac terminates caudally at S2.
children, S3
space between vertebral bones and dura mater is called what
The space between the dura mater and the vertebral bones is the epidural
To which vertebral level does the arachnoid mater descend?
S2
