UE + Brachial Plexus Anatomy Flashcards
shoulder
- scapula
- most proximal upper limb joint
- consists of scapula, clavicle and proximal humerus
arm bone
humerus
forearm bones
radius and ulna
wrist
- carpals
- distal radius and ulna contact carpals
- carpals contact carpals
- carpals contact metacarpals
palm bones
metacarpals
finger bones
digits and phalanges
elbow
-consists of distal humerus, proximal radius, and proximal ulna
hand
- palm (metacarpals)
- fingers (phalanges)
what bone does the biceps brachii never attach to?
humerus
shoulder flexion
swings the upper limb forward at the shoulder
shoulder extension
swings the upper limb backward at the shoulder
dorsal (posterior) muscles of upper limbs
elevators or extensors
ventral (anterior) muscles of upper limbs
depressors or flexors
pectoris major and minor innervation
- lateral pectoral nerve (from lateral cord)
- medial pectoral nerve (from medial cord)
deltoid innervation
axillary nerve
triceps brachii + all other extensors (superficial and deep) innervation
radial nerve
anterior flexors in arm innervation
musculocutaneous nerve
anterior flexors in forearm and hand innervation
median and ulnar nerves
progression of main artery of upper limb
- suclavian
- axillary (at axilla)
- brachial
- brachial splits into radial and ulnar
structures ANTERIOR to ASM
- phrenic nerve (to diaphragm)
- subclavian vein
- transverse cervical artery
- suprascapular artery
structures POSTERIOR to ASM
- brachial plexus
- subclavian artery
Erb’s palsy
- results from damage to upper roots of the plexus that serve flexors in shoulder and arm
- result = extension and pronation
- damage to C5, C6, C7
- mostly explained by loss of innervation of musculocutaneous nerve
muscles innervated by musculocutaneous nerve
- coracobrachialis
- brachialis
- biceps brachii
klumpke’s palsy
- results from damage to the lower roots (C7, C8, T1) of the brachial plexus and muscles that move the hand and wrist
- result = limitations on elbow extension and wrist flexion
what does the long thoracic nerve innervate?
serratus anterior
scapular winging
a result of damage to the long thoracic nerve (C5-C7) and weakness in serratus anterior
flexors of hand
attach to medial epicondyle of humerus
extensors of hand
attach to lateral epicondyle of humerus
innervation of extensors of hand
radial nerve
innervation of flexors of hand
- median nerve to forearm and thumb
- ulnar nerve to ulnar side of forearm and much of the hand
layer 1 of superficial flexors of hand/wrist
- arise at or near medial epicondyle
- brachioradialis (radial)
- pronator teres (median)
- flexor carpi radialis (median)
- palmar longus (median)
- flexor carpi ulnaris (ulnar)
- flexes wrist/hand
layer 2 of superficial flexors of hand/wrist
- arises at or near medial epicondyle
- flexor digitorum superficialis (median)
- flexes fingers
layer 3 of deep flexors of hand/wrist
- flexor pollicis longus (median) - flexion of fingers to make fist
- flexor digitorum profundus (half median/half ulnar) - flexion of upper half of finger
layer 4 of deep flexors of hand/wrist
-pronator quadratus (median) - pronation of wrist
which nerve passes under the carpal tunnel?
median nerve
extensor muscles of hand/wrist
- arise from lateral epicondyle and go to fingers (thumb muscles not included)
- innervated by radial nerve
- extensor carpi radialis longus
- extensor carpi radialis brevis
- extensor carpi ulnaris
- extensor digitorum
- extensor digiti minimi
extensor muscles going to thumb and index finger
- arise primarily from ulna
- innervated by radial nerve
- anconeus
- supinaotor
- adductor pollicis longus
- extensor pollicis brevis
- extensor pollicis longus
- extensor indicis
thenar
thumb side
median but one small part ulnar (flexor pollicis brevis)
hypothenar
pinky side
ulnar nerve
intrinsic muscles of hand on each side you will have (3 things)
- a short flexor muscle
- an abductor muscle
- an opponens muscle
ulnar claw hand
ulnar nerve damage that leads to weakness in the 3rd and 4th lumbricals
hand of benediction
median nerve damage that leads to weakness in 1st and 2nd lumbricals
radial nerve innervation
- motor innervation to all of the muscles in the extensor compartments of the arm and forearm
- sensory innervation to the part of the dorsum of the arm, forearm and hand
median nerve innervation
- motor innervation to most of the forearm flexors, thenar muscles, 1st and 2nd lumbricals
- sensory innervation to the rays I, II, III and the lateral 1/2 of digit IV
ulnar nerve innervation
- motor innervation of 1 half of forearm flexors, hypothenar muscles, adductor pollicis, 3rd and 4th lumbricals, all interossei
- sensory innervation to medial 1/2 ray 4 and ray 5
