Spinal cord and Spinal nerves Flashcards
(28 cards)
where does the spinal cord start
foramen magnum (hole in the base of the skull
where does the spinal cord end
inferior border of 1st lumbar vertebra (L1)
what can the spinal cord be found in
- within a sac made of meninges that fits inside the spinal cavity
- this sac is filled with cerebrospinal fluid
where is the spinal cavity located
spinal cavity can be found within the vertebrae and extends all the way down to the coccygeal vertebrae
what is the posterior position in neuro called
dorsal
what is the anterior position in neuro called
ventral
what is the conus medullaris
tapered cone at the end of the spinal cord, made up of non-neural tissue
it serves as an attachment point for filum terminale
what is the filum terminale
a thin, fibrous strand that extends from the end of the spinal cord (conus medullaris) to the coccyx
anchors the spinal cord
how many spinal nerves are there
the spinal cord has 31 segments, and one pair of spinal nerves is associated with each segment on each side
how are the spinal nerves named and what is the one exception
spinal nerves are named by the vertebra they exit below, however there is only 7 cervical vertebrae and 8 cervical spinal nerves
the first cervical spinal nerve exits between the skull and the first cervical vertebrae
where do the spinal nerves exit from
exit the vertebral column at the level appropriate to their origin
what is the cauda equina
a large collection of long nerves to end of spinal
what is a sulcus
a furrow
what is a fissure
a deep sulcus
what is white matter made of in the CNS
axons
what is grey matter made of in the CNS
cell bodies
where does efferent information flow from the CNS
Ventral horn (contains somatic motor neurons) through the ventral roots
what would happen to efferent signaling when ventral horn gets damaged
paralysis of muscles supplied by somatic motor neurons from this spinal cord segment, on same side only
where does afferent information flow into CNS
input zone in body associates with receptors for sensory stimulus
cell bodies of sensory neurons can be found in dorsal root ganglion
output zone enters the spinal cord through dorsal roots
what would happen to the afferent information if the dorsal horn is damaged
loss of sensation from regions of the body supplied by sensory neurons from this spinal cord segment, on same side only
what happens to the spinal nerves once they leave the vertebral column
they divide into the dorsal and ventral rami
what is the rami communicans
nerve fibers that act as connecting branches between spinal nerves and the sympathetic trunk, facilitating the transfer of autonomic signals
what is the endoneurium
covers the axon (myelinated or not)
a thin layer of connective tissue that directly surrounds individual nerve fibers within a peripheral nerve
what are fascicles
endoneurium covered axons that are bundled together
