Nervous System Flashcards
Myotomes of brachial plexus
C5 - shoulder
C6 - elbow
C7 - wrist
C8 & T1 - fingers
Brachial plexus
Innervation of the upper limb
C5-T1
Nerves = musculocutaneous, axillary, median, radial, ulnar
Myotomes of lumbar plexus
L3 - hip
L4 - knee
Myotomes of sacral plexus
L5 & S1 - ankle
Rhyme for reflexes
S1-S2 buckle my shoe (Achilles tendon test)
L3-L4 kick the door (patellar tendon test)
C5-C6 pick up sticks (biceps brachii tendon test)
C7-C8 lay them straight (triceps brachii tendon test)
A patient presents with weakness in the hand and loss of sensation on the front surface of the Palm on the ulnar side. Muscular testing reveals an inability to firmly hold a piece of paper between the fingers and a weak grip, especially on the ulnar side. The most likely cause would be a lesion to:
a) C8 and T1 spinal levels
b) musculocutaneous nerve at the elbow
c) ulnar nerve at the carpal tunnel
d) ulnar nerve in Guyon’s tunnel
e) ulnar nerve in the Cubital tunnel
e) ulnar nerve in the Cubital tunnel
Since Flexion of the fingers is caused by innervating muscles in the forearm, the lesion has to be at the elbow
Ulnar nerve provides motor and sensory to the ulnar side of forearm and hand
Musculocutaneous nerve
Innervates muscles of the arm
Superficial cutaneous distribution of forearm
Median nerve
Innervates muscles of the forearm - except flexor digitorium profundus
Superficial cutaneous distribution to medial of hand
Ulnar nerve
Innervates the flexor digitorum profundus muscle
Superficial cutaneous distribution to the pinky and third finger
deltoid (anterior fibers)
flexion & medial rotation
axillary nerve
deltoid (middle fibers)
abduction
axillary nerve
deltoid (posterior fibers)
extension & lateral rotation
axillary nerve
supraspinatus
abduction
suprascapular nerve
infraspinatus
lateral rotation
suprascapular nerve
teres minor
extension & lateral rotation
axillary nerve
subscapularis
medial rotation
subscapular nerve
biceps
flexion
musculocutaneous nerve
triceps
extension
radial nerve
thenar group
thumb movement
median nerve
lumbricals
finger abduction
median & ulnar nerves
hypothenar group
pinky movement
ulnar nerve
psoas
trunk flexion
L1-L4
iliacus
thigh flexion femoral nerve (L2-L3)
gluteus maximus
extension & lateral rotation of hip
inferior gluteal nerve
tensor fascia lata
thigh abduction & internal rotation
superior gluteal nerve
deep external rotators (piriformis, obturator internus, superior & inferior gernelli)
hip abduction/adduction & external rotation
L5-S1
quadriceps
knee extension
femoral nerve
sartorius
thigh flexion, abduction & rotation
femoral nerve
adductor group (adductor magnus, gracilis)
thigh adduction
obturator nerve
popliteus
knee flexion & medial rotation
tibial nerve
gastrocnemius & soleus
plantar flexion
tibial nerve
tibialis posterior
plantar flexion & inversion
tibial nerve
flexor digitorum
plantar flexion & toe flexion
tibial nerve
tibialis anterior
dorsiflexion & inversion
fibular nerve
extensor digitorum
dorsiflexion & toe extension
fibular nerve
fibular group
dorsiflexion & eversion
fibular nerve
flexor digitorum brevis
toe flexion
tibial nerve
extensor digitorum brevis
toe extension
fibular nerve
a patient eperiences loss of sensation in a stripe of skin along the medial aspect of the arm and forearm. This is accompanied by paresis of the finger adductors. The lesion would most likely be located in the:
a) lower roots of the brachial plexus
b) ulnar nerve
c) median nerve
d) posterior divisions of the brachial plexus
e) upper roots of the brachial plexus
a) lower roots of the brachial plexus
