Nerves Flashcards
Musckulocutaneous Nerve
Segment - C5 C6
Innervation - coracobrachialis, biceps, brachialis
Distribution - anterolateral surface of forearm
Axillary Nerve
Segment - C5 C6
Innervation - deltoid, teres minor
Distribution - lateral arm over lower portion of delt
Radial Nerve
Segment - C5-8, T1
Innervation - triceps, anconeus, brachioradialis, and supinator, wrist/finger/thumb extensors
Distribution - posterior are/forearm and radial sideof posterior hand
Median nerve
Segment - C6, 7, 8, T1
Innervation - pronators, writs/finger flexors on radial side, most thumb muscles
Distribution - palmar aspects of thumb, 2nd, 3rd and radial half of 4th fingers
Ulnar Nerve
Segment - C7 C8 T1
Innervation - flexor carpi ulnaris, felxor digitorum profundus (medial half), interossei, 4th and 5th lumbricals
Distribution - medial portion of 4th finger and 5th finger
Sciatic Nerve
Segment - L4-S3
Innervation - HS and adductor magnus
Distribution - through its terminal branches of the tibial, superficial fibular, and deep fibular nerves
Femoral Nerve
Segment - L2 L3 L4
Innervation - sartorius, quads, iliacus and pectineus
Distribution - middle ant thigh and medial thigh prox to knee
Tibial Nerve
Segment - L4-S3
Innervation - gastroc/soleus, plantaris, popliteus and tib post
Distribution - posterolateral calf, ankle and heel
Superficial Fibular Nerve
Segment - L5-S2
Innervation - fubularis longus/brevis
Distribution - anterolateral distal lower leg and ankle and most of dorsum of foot
Deep Fibular Nerve
Segment - L4-S2
Innervation - tib ant, ext hallucis longus/brevis, ext dogitorum longus/brevis, fibularis tertius, 1st and 2nd dorsal interossei
Distribution - web space bwteen 1st and 2nd toes on the dorsum of foot
CN 1
Olfactory
Fx- smell
Damage - anosmia (loss of smell)
CN 2
Optic
Fx- sight, pupillary reflexes
Damage - monocular blindness, loss of pupillary constriction, absent blink reflex
CN 3
Oculomotor
Fx- moves eye and elevates upper eyelid
Damage - ptosis, dilation of pupil, loss of accomodation of light reflex
CN 4
Trochlear
Fx- motor nerve for superior oblique muscle
Damage -
CN 5
Trigeminal
Fx- mastication and sensory nerve of head
Damage - loss of facial sensation, weak mastication, deviation of opened jaw to ipsilateral side
CN 6
Abducens
Fx- abducts eye (via nerve supply to lateral rectus muscle)
Damage - diplopia, convergent squint (medial strabismus), and abductor paralysis or ipsilateral eye
CN 7
Facial
Fx- facial expression, speeach articulation, winking ingestion or food/drink, taste/salivary and nasal secretions
Damage - ipsilateral facial paralysis, dry mouth, loss of taste anterior third of tongue
What condition results from damage to CN 7?
Facial
Bell’s Palsy
Injury/paralysis to what nerve causes foot drop and weakness in the intrinsic foot muscles?
Deep fibular nerve
CN 8
Vestibulocochlear
Fx- hearing, maintenance of equilibrium
Damage - vertigo, nystagmus, tinnitus, loss of hearing
CN 9
Glossopharyngeal
Fx - elevates pharynx, salivary secretion, taste
Damage - slight dysphagia, partial dry mouth, loss of taste on posterior 3rd or tongue
CN 10
Vagus
Fx - phonation, visceral sensations/reflexes, cardiac depressor, bronchoconstrictor, GI tract peristolsis/secrection
Damage - palpitations, tachycardia, comiting, slowing of respiration, hoarseness, anesthesia of larynx
CN 11
Accessory
Fx - deglutition and phonation, movement of head and shoulders
Damage - weakness in shrugging ipsilateral shoulder, turning head opposite side
CN 12
Hypoglossal
Fx - movements of tongue
Damage - unilateral paralysis of tongue
What are the DTR’s and what level are they testing?
Biceps - C5-6 Brachioradialis - C6 Triceps - C7 Patellar tendon - L3, L4 Achilles tendon - S1, S2
Grading scale for reflexes
0 = absent reflexes = areflexia 1+ = hyporeflexive, indicates LMN injury 2+ = normal 3+ = hyper-reflexive, indicates UMN injury
How does neural tension testing work?
by stretching the peripheral nerves with specific mvm’ts, the mobility of the spinal dura and nerve roots can be tested
SLR Biases
SLR - sciatic
SLR + DF + EV = tibial nerve
SLR + PF + INV = fibular nerve
SLR + DF + INV = sural nerve
What are two tests used to screen for spinal cord signs?
- Ankle clonus
leg in slight knee flex and rapidly DF ankle
+ve with spasmodic alternations of muscle contraction
2.Babinkski’s test
stroke plantar aspect of foot from to heel to base of great toe
+ve if great toe moves into DF and other toes fan
