Anatomy 3 - spinal nerves Flashcards
what is the pattern of spinal nerve innervation of upper limb
comes out horizontally in development in horizontal strips along the limb buds
like putting arm through clingfilm lol
what are somatic general sensory symptoms
pain pins and needles numbness sensitivity thermal loss of co-ordination/balance/clumsiness
somatic motor symptoms
muscle stiffness, tightness, or spasm
muscle floppiness or looseness
muscular weakness
loss of co-ordination/balance/clumsiness
what does each pair of spinal nerves do
supplies everything in one segment of the body wall
general somatic sensation
general somatic motor
sympathetic motor
spinal reflexes
how do you clinically test spinal nerve function
test each spinal nerve segments sensory function
-dermatomes
test each spinal nerves motor function
-myotomes
test both of the above simultaneously with spinal cord reflexes
what spinal nerves innervated the upper limb and trunk
C1-T12
what dermatome is the pubic symphysis
T12
what dermatome is the nipple
T4
what dermatome is the umbilicus
T10
what spinal nerves innervated the lower limb
L1 (groin) - S5 (perianal skin)
how does dermatomal testing check the integrity of
dorsal rootlets
dorsal root
spinal nerve
what rami forms plexuses
anterior rami
cervical plexus
brachial plexus
lumbar plexus
sacral plexus
what anterior rami do not contribute to a plexus
T2-T12
what spinal nerve roots make up the femoral nerve
L2, L3 and L4
what named nerves are from cervical spinal roots C2-C8
little - lesser occipital (C2)
goats - Great auricular nerve (C2,C3)
tread - Transverse cervical (C2,3)
softy - Supraclavicular nerves (C3,4)
what are the named nerve cutaneous innervation of the upper limb
Supraclavicular nerves (C3,4) Axillary nerve (C5,6) Cutaneous branch of the musculocutaneous nerve (C5,6,7) Median nerve (C5,6,7,8,T1) Ulnar nerve (C7,8,T1)
what are the named nerve cutaneous innervation of the leg (anterior)
Subcostal nerve (T12) Femoral branch of genitofemroal never (L1,2) Ilioinguinal nerve (L1) Obturator nerve (L2,3,4) Lateral cutaneous nerve of thigh (L2,3) Femoral nerve (L2,3,4) Saphenous nerve (from femoral L3,4) Superficial fibular nerve (L4,L5, S1) Deep fibular nerve (L5)
Sensory pathway side
look at it idk
where is the cervical plexus
C1-C4
what is the brachial plexus
C5-T1
what do T2-L3 motor axons supply
postural back muscles
intercostal muscles
anterolateral abdominal wall muscles
what do lumbosacral plexus L1-S4 axons supply
muscles of lower limb
perineal skeletal muscles
where is the primary motor cortex
pre-central gyrus
what % of axons cross
85%
what is a reflex
involuntary response to stimulus - depends on integrity of arc pathway
describe the patella reflex arch (knee jerk)
Patella tendon tapped
Stretches the quads
Muscle spindles initiate APs in the anterior rami axons in the femoral nerve
Sensory APs conducted to the dorsal horn of L3
Axons pass into anterior horn to synapse on LMNS that supply quads
AP conduced via lower motor neuron axons on femoral nerve to reach quads neuromuscular junction
muscle contracts to extend knee joint
what do upper motor neuron lesions cause
spasticity
what do lower motor neuron lesions cause
flaccidity
myotome test for L2
hip flexion
if pins and needles in dermatomal pattern but motor function okay where is the lesion
in the posterior spinal rootlets
