ganglion
collection of nerve cell bodies in the PNS
dorsal root ganglion contains which kind of nerves?
sensory
ventral root ganglia contain which kind of nerve?
motor
spinal nerve
when dorsal and ventral root ganglia fuse
what is contained in the subarachnoid space?
CSF and fat and blood vessels
denticulate ligament
extension of the pia mater,
part of the anchoring mechanism to keep the spinal cord in place
supracristal line
highest point of the iliac crest
conus medullaris
terminal end of spinal cord (At L1-L2)
part of CNS
filum terminale
extension of pia mater from conus medullaris to cocccyx
fuses with arachnoid mater at coccyx
(not nervous tissue-only CT)
cauda equina
horse tail-like nervous tissue below L1
Part of PNS
why is the spinal cord thicker at the cervical and lumbar areas?
they have nerve endings for upper and lower extremities
gracile fasciculus
named part of dorsal columns
cuneate fasciculus
named part of dorsal columns
what kind of sensation travels in the dorsal columns?
finer vibration, procreation, discriminative touch
somatic motor neuron cell bodies make up what?
grey matter
what is inside the central canal?
CSF
alpha motor neuron
somatic motor neuron
-big fat and highly myelinated
thalamus
major sensory center for the brain
what is the hallmark of spinothalamic tract?
crosses as soon as it enters the spinal cord
what are the target organs for the autonomic nervous system?
smooth muscle
cardiac muscle
glands
proprioception
knowing where you are in space
what will sensory neurons do when they enter spinal cord?
- synapse on interneurons
- go directly into white matter and travel up or down several segments
- cross over spinal cord
describe the cervical spinal cord
has tons of white matter and a large diameter
describe the thoracic spinal cord
small diameter
small anterior and posterior horns
sympathetic cell bodies are present
describe the lumbar spinal cord
nearly circular
large anterior and posterior horns
less white matter compared to cervical
describe the sacral spinal cord
small diameter, but large amt of gray matter
small amt of white matter
what cranial nerves are the nuclei for parasympathetic
vagus X
glossopharygeal IX
facial VII
oculomotor III
what is an inborn reflex?
have since birth
what is an acquired reflex?
learned reflex (motor learning)
what are the free nerve pain receptors?
nociceptors
how many nerves are involved in the withdrawal reflex?
3
what is the crossed extensor reflex?
when nociceptor senses pain on one side that causes withdrawal, motor neurons tell the other side to compensate
stretch reflex
mono synaptic
proprioreceptors in skeletal muscle that monitors change in length of muscle
prevent overstretching and damage of the muscles
what is the muscle fiber Ia?
muscle spindles
what is the muscle fiber Ib?
tendon organs
what is the muscle fiber II, Ab?
muscle spindles, mechanoreceptors
what is the muscle fiber Ag?
thermoreceptors, mechanoreceptors and nociceptors
what is the muscle fiber C?
thermoreceptors, mechanoreceptors, nociceptors
gamma motor neurons do what?
maintain the tension and contractile state of the muscle
-cell bodies in ventral gray matter
clonus
isolated movement of the reflexed area
reciprocal inhibition
when reflex is activated, an inhibitory response goes to the antagonistic muscle group to prevent contraction
hypotonic
floppy, low tone
hypertonic
parkinsons (rigidity)
spasticity
what are dermatomes?
provides sensory input to CNS
what are myotomes?
levels of spinal cord that contribute to innervation of skeletal muscle
