Ch 12 Spinal Cord & Spinal Nerves Flashcards
where does spinal cord stop and end?
foramen magnum to 2nd lumbar vertebra; newborn’s extends entire length
2 enlargements of spinal cord are located where?
thoracic enlargement and lumbosacral enlargement
horse’s tail
cauda equina
where the cord ends
conus medullaris
what keeps the spinal cord from sliding up and down and anchors cord to coccyx
filum terminale
spinal meninges
dura mater: cont with spinal nerve (epineurium)
arachnoid mater: thin and wispy
pia mater: bound tightly to brain and spinal cord
attach cord to dura mater
denticulate ligaments
spaces in spinal meniges
epidural: blood vessels, areolar CT, and fat
subdural: serous fluid
aubarachnoid: CSF and blood vessels
how do you determine which is the front side in the cross section of a spinal cord?
anterior median fissure vs posterior median sulcus
white matter of the spinal cord consists of
columns (funiculi): ventral dorsal and lateral
which are divi into tracts (fasciuli)
gray matter
horns
- posterior horn: (dorsal, sensory)
- anterior horn: (ventral, somatic motor)
- lateral horn: (autonomic nervous system)
connect left and right sections of spinal cord
commissures
what are the two nerve roots and what type of signals do they carry?
dorsal (posterior) root: ganglion ; carries sensory
ventral (anterior) root: carries motor
dorsal root + ventral root = ???
spinal nerve
what are the names of the layers of connective tissue that surround the peripheral nerves?
axon w/ schwann cells
endoneurium: surround individual neurons
perineurium: surrounds axon groups (fascicles)
epineurium: surrounds entire nerve
how many pair of spinal nerves?
31 pair; 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal
diagram of cutaneous regions innervated by each spinal nerve?
dermatomal map
supplies mm and skin of back
dorsal ramus
in thoracic region form intercostal nerves supplying intercostal mm and skin
ventral ramus
5 plexuses?
cervical, brachial, lumbar, sacral, coccygeal
sympathetic chain ganglia?
communicating rami ; ANS
major nerves in the cervical plexus
phrenic- controls diaphragm
major nerves in the brachial plexus
radial, ulnar, axillary, muscoskeletal, and median
what causes carpal tunnel syndrome?
same repetitive mvmt makes muscles grow and there’s no room so it squishes this nerve and hurts very bad
major nerves in lumbar plexus
obturator : medial thigh
femoral: anterior thigh and leg
major nerves in sacral plexus
tibial and fibular break off of the sciatic nerve
major nerve in coccygeal plexus
coccygeal nerve: pelvic floor
sensory comes into CNS, attaches to interneuron, attaches to motor neuron, effects targeted organ
somatic reflex arc
how many motor neurons does a somatic reflex arc have?
one
how many motor neurons does a autonomic reflex arc have?
two
sensory neuron attaches to preganglionic motor neuron, this neuron attaches to postganglionic neuron in either the sympathetic trunk ganglion or passes through the STG to the collateral ganglion, then effect the target organ
autonomic reflex arc
