Lec 15 Nervous System 3 Peripheral Nervous System Flashcards
which pressure receptor responds to light pressure?
meissners corpuscles
which pressure receptor responds to deep pressure?
pacinian corpuscles
what is the purpose of proprioceptors?
3D acuity, position sense.
what is the spinal nerve formed by?
both ventral and dorsal roots
in order to have complete loss of sensation, how many dermatomes do you need to lose?
3 adjacent dermatomes
which dermatome is located at the nipple?
T4
which dermatome is located at the umbilicus?
T10
what is referred pain?
sensory info coming from organs is perceived as rising from other locations
what do branches of the dorsal primary rami supply?
muscles and skin of posterior head, neck, and back
where is the cervical plexus located?
c1 - c4
which nerve keeps you alive? where is it located?
phrenic nerve
c3, c4, c5
where is the phrenic nerve sensory? where is it motor?
sensory : skin of neck
motor : diaphragm
where is the brachial plexus located?
c5 - T1
where is the brachial plexus sensory & motor?
sensory: skin of shoulder and upper limb
motor : muscles of shoulder and upper limb
what are the branches of the brachial plexus? (upper body)
axillary, musculocutaneous, radial, ulnar, median
what structures do the axillary nerve innervate?
sensory: skin of shoulder
motor : deltoid muscle
what does a deficit of the axillary nerve cause?
cannot abduct
what structures does the musculocutaneous nerve innervate?
sensory - skin of forearm
motor - biceps brachii, brachialis (muscles of anterior arm)
what does a deficit of the musculocutaneous nerve cause?
cannot supinate / weak supination
no flexion of elbow
what structures does the radial nerve innervate?
sensory : portions of posterior arm and forearm
motor : triceps, extensors of forearm
what does a deficit of the radial nerve cause?
wrist drop (cannot extend wrist)
what structures does the ulnar nerve innervate?
motor:
flexor carpi ulnaris
flexor digitorum (medial only)
lumbricals (medial only)
what does a deficit in the ulnar nerve cause?
claw hand
what structures does the median nerve innervate?
motor:
flexors of forearm
thenar eminence (thumb)
lumbricals (lateral 2)
what does a deficit in the median nerve cause?
ape hand (loss of opposition of thumb) carpal tunnel syndrome
what does the femoral nerve innervate?
quadriceps
what does a deficit in the femoral nerve cause?
no knee extension [no afferent signal if nerve is severed]
where is the lumbosacral plexus located
L1 - S4
what does the obturator innervate?
adductors, muscles of medial thigh
what does a deficit in obturator cause?
no adduction in lower limb
what are 2 branches of the sciatic nerve?
tibial, common fibular
what are 2 branches of the common fibular nerve? what do each innervate?
deep fibular nerve: muscles of anterior leg
superficial fibular nerve: muscles of lateral leg
what structures do the sciatic nerve innervate?
hamstrings
what does a deficit in the sciatic nerve cause?
cant flex knees
what structures does the tibial nerve innervate?
gastrocnemius, soleus, tibialis posterior (muscles of posterior leg)
what does a deficit in the tibial nerve cause?
plantar flexion deficit
what is pudendal nerve block used for?
childbirth
what does loss of the pudendal nerve cause?
incontinence - loss of bladder control
