anatomy of spinal nerves Flashcards
from medial to lateral describe the arrangement of the spinal nerves
begins with either anterior or posterior horn in the spinal cord
then to either anterior or posterior rootlets which then form a root which then join form the mixed spinal nerve
from the spinal nerve you get a an anterior and posterior ramus branching off
anterior -motor or sensory?
motor
what does a spinal nerve supply to its area of the body wall?
somatic general sensory
somatic motor
sympathetic motor to organs
reflex functions
where would you examine C2 dermatome?
back of scalp and adams apple
where would you examine C3 dermatome?
back of neck and jugular notch
where would you examine C4?
clavical and shoulder tip
where would you examine C5 dermatome?
badge patch on the arm
where would you examine C6 dermatome?
thumb
where would you examine C7 dermatome?
middle finger
where would you examine C8 dermatome?
little finger (pinky)
where would you examine T1 dermatome?
medial forearm
where would you examine T2 dermatome?
medial arm and sternal angle
where would you examine T4 dermatome
male nipple
where would you examine T8 dermatome
xiphoid process
where would you examine T12 dermatome
pubic symphysis
where would you examine L1 dermatome
groin
where would you examine L2 dermatome
anterior thigh
where would you examine L3 dermatome
anterior knee
where would you examine L4 dermatome
medial malleolus
where would you examine L5 dermatome
dorsum of foot
where would you examine S1 dermatome
heel
where would you examine S2 dermatome
posterior knee
where would you examine S3 dermatome?
buttock
where would you examine S 4 dermatome?
perineum
where would you examine S5 dermatome?
perianal skin
describe what is happening when a dermatome is tested for sensory function?
stimulation in anterior aspect of right T10 dermatome
AP generated by receptors in that segement
AP travels along axons to anterior ramus
AP travels to T10 spinal nerve
AP travels to T10 posterior root then to posterior rootlets
AP travels to posterior horn of spinal cord
what nerve is made up from L2, L3 and L4
femoral nerve
what is the other name for the anterior rami of T2-T11
intercostal nerves
anterior rami of T12=?
subcostal nerve
the area below T12 is supplied by what 2 nerves>
iliohypogastric and ilioinguinal nerves
what supplies the skin of the anatomical snuff box?
radial nerve
what nerve supplies the skin in the web between big toe and second toe
deep fibular nerve
what nerve supplies sensory to the skin on the dorsum of the foot?
superficial fibular nerve
what nerve supplies sensory to most of posterior thigh>?
posterior cutaneous nerve of thigh
what nerve supplies deltoid and teres minor?
axillary nerve
what nerve supplies muscles of anterior arm?
musculocutaneous
what muscles supplues anterior forearm, thenar muscles and lumbricals 1+2
median nerve
what nerve supplies the muscles of the posterior arm and posterior forearm
all extensors of carpus and digits and abbuctor pollicus longus
radial nerve
what nerve supplies some of anterior forearm ( flexor carpis ulnaris and adductor pollicus and medial half od flexor pollicus longus), and hypothenar muscles and lumbrical 3+ 4 and ALL interossei muscles
ulnar nerve
what nerve supplies lateral lower leg muscles
superficial fibular nerve
what nerve supplies the muscles in anterior lower leg?
deep fibular nerve
what nerve supples the quads, sartorius and pectineus
femoral nerve
what is happening when a spinal nerve myotome is tested?
AP generated by voluntary intention in primary somatosensory cortex
AP conducted via UMN of axons of corticospinal tract
AP travels to anterior horn of L3 spinal cord
UMN synapses with L3 LMN
AP travels to either L3 postior or anterior ramus
AP via L3 anterior rami often weave through the lumar plexus via named nerve
APs reach neuro motor junction of supplied muscle
what does this describe?
patellar tendon gets tapped
stretch applied to quads via quad tendon
quad muscle spindle inititiates AP in anterior rami axons of femoral nerve
AP conducted to dorsal horn of spinal cord
axons then synapse upon LMN that supply quads
AP then reaches NMJ of quads causing them to contracts and bend the knee
