exam 2 spinal cord Flashcards
where does the spinal cord lay? and what vertebrae does it run from?
within the vertebral canal
runs from foramen magnum to L1
cervical enlargement
contains neurons that innervate upper limb
lumbar enlargement
contains neurons that innervate lower limb
conus medullaris
pointed end of spinal cord
cauda equina
collection of nerve roots comin off of conus medullaris
filum terminale
thin strand of pia mater that anchors conus medullaris to coccyx
how many pairs of spinal nerves?
31 pairs
1 on left and 1 on right
how many pairs of cervical spinal nerves?
8 (C1-C8)
how many pairs of thoracic spinal nerves?
12 (T1-T12)
how many pairs of lumbar spinal nerves?
5 (L1-L5)
how many pairs of sacral spinal nerves?
5 (S1-S5)
how many pairs of coccygeal spinal nerves?
1 (Col)
What exactly is a nerve?
formed from MANY axons bundled together in C wrappings
what is the order of meninges of spinal cord from superficial to deep
epidural space dura mater arachnoid mater subarachnoid space pia mater
what is the epidural space
found between dura mater and vertebra
-filled with fat and blood vessels
dura mater is composed of
dense CT
describe the arachnoid mater
thin spider-web like membrane
what is the subarachniod space
space between arachnoid and pia mater
describe the composition of pia mater
- thin layer of CT
- adheres to spinal cord
central canal
- space within gray matter of spinal cord
- lined with ependymal cells
- contains CSF
gray matter
contains nerve cell bodies, unmyelinated axons, glial cells and interneurons
- anterior horns
- lateral horns
- posterior horns
- gray commissure
what are anterior horns
cell bodies of somatic motor neurons
-innervate skeletal muscle
what are lateral horns
cell bodies of automatic motor neurons
- only in T1-L2 of spinal cord
- innervate cardiac muscle, smooth muscle, glands
what are posterior horns
contain interneurons and axons of sensory neurons
what is gray commissure
unmyelinated axons traveling crossing one side to another
-contains central canal
white matter
contains both ascending and descending spinal cord tract myelinated axons: -anterior funiculi -lateral funiculi -posterior funiculi
spinal cord tracts
bundles of axons that run in the white matter of spinal cord
ascending tracts
containing sensory axons
-travels from body to brain
descending tracts
contains motor axons
-travels from the brain to the body
the anterior root is composed of what type of axons
motor axons
the posterior root is composed of what type of axons
sensory axons
the posterior root ganglion is composed of what type of axons
contains cell bodies of sensory neurons
what occurs when anterior and posterior roots unite?
they form a spinal cord which contains both motor and sensory axons