brachial plexus Flashcards
upper trunk brachial plexus injuries are often caused by: (list 2 mechanisms)
trauma eg 1) falling onto head or 2) lateral flexion of baby’s head during birth
classic name for upper trunk brachial plexus injury; also nerve roots involved
Erb’s palsy (waiters palsy); c5-c6 roots
name of shape for arm adducted, medially rotated, extended, pronated
waiter’s tip
lower trunk brachial plexus injuries are often caused by: (2 mechanisms)
trauma eg (1) grabbing tree on way down or (2) pulling baby’s arm during exit from birth canal
numb lateral forearm and weak flexion at elbow and weak supination associated with what lesion?
musculocutaneous nerve lesion
klumpke palsy presents with and is associated with x injury
total claw hand upper brachial plexus trunk
nerve lesion causing numb sargeant’s patch and difficulty abducting >15 degrees at shoulder
axillary nerve lesion
dorsal lateral hand (in anatomical perspective) and dorsal forearm and arm sensory loss coupled with either WRIST DROP or weak elbow extension, triceps reflex, and absent supinator reflex
radial nerve lesion
sensory loss to lateral palmar hand//thenar eminance
median nerve lesion
extending fingers results in claw for lesions of these two nerves: distinguish each
ulnar and median
proximal median nerve lesion results in …. when trying to make a fist hint: similar to distal ulnar nerve except different context of attempted motion to get to it
Pope’s blessing
what structures pass through the interscalene triangle ?
brachial plexus and subclavian artery
define thoracic outlet syndrome
compression of neurovascular structures of upper limb as they go through costoclavicular space
sxs of TOS
pain in upper extremity from point of compression; pallor and numbness and weakness of fingers. sensitivity to cold
poorly fitting crutches or sleeping on arm can injure this nerve
radial
muscles supplied by axillary nerve
deltoid and teres minor
posterior compartment of forearm and arm supplied by
radial nerve
muscles supplied by musculocutaneous
biceps brachii, brachialis and coricobrachialis
waiter’s tip assoc. with two nerves:
axillary and musculocutaneous
biceps reflex absence could signify lesion in this nerve
musculocutaneous nerve
describe course of median nerve in relation to another vessel as it passes through the arm
goes down anterior arm with brachial artery, and is medial to brachial artery at lvl of mid arm onward (distally)
muscles supplied by median nerve:
I. anterior forearm except for 1) flexor carpi ulnaris and 2) ulnar half of flexor digitorum profundus II. First and second lumbricals; opponens pollicis; abductor pollicic brevis; flexor pollicis brevis superficial head
ulnar nerve passes next to this epicondyle on humerus:
medial
ulnar nerve supplies
flexor carpi ulnaris, ulnar half of flexor digitorum profundus, and all intrinsic muscles of hand except for thenar and first second lumbricals
describe sensory innervation of arm and forearm in terms of 1) musculocutaneous nerve (which becomes lateral cutaneous nerve of forearm); 2) radial nerve (posterior brachial and antebrachial, inferior-lateral cutaneous nerve); 3) medial antebrachial and brachial nerves
describe sensory innervation of hand in terms of median, radial, and ulnar nerves
see diagram
describe collateral circulation around scapula in terms of the 3 arteries that comprise it
1) suprascapular artery 2) transverse cervical (aka dorsal scapular) artery 3) circumflex scapular artery (from subscapular artery)
which two areas are the borders between (within) which you may put ligatures on the axillary artery?
between the thyrocervical trunk and the subscapular branch.
