arm, cubital region, arthrology of elbow

trochlea

articulates with ulna

capitellum

articulates with radius

medial epicondyle

attachment site for muscles in anterior compartment of forearm

lateral epicondyle

attachment site for muscles in posterior compartment of forearm

anterior compartment of the arm

biceps brachii, brachialis, coracobrachialis

forearm flexors

supplied by the musculocutaneous nerve

brachialis

also takes some innervation from the radial nerve (C6)

forearm flexors

almost twice as strong as the forearm extensors in all postions

biceps brachii

no attachment to humerus

biceps brachii

3 joint muscle, effects movement at GH elbow and radioulnar joints

actions of biceps brachii

- GHJ flexion (long & short head)

- GHJ adduction and IR (short head)

- elbow flexion

- forearm supination

biceps brachii

helps rotator cuff to depress humeral head

biceps brachii

active only against resistance in a semi pronated postion

biceps brachii

barely operates as a flexor with forearm pronated even against resistance

biceps brachii

flexes the forearm with elbow extended

long head of biceps

sits between insertion of pec major and teres major superficial to insertion of lats

long head tendon

supported at the head of humerus by the transverse humeral ligament

bicep tendon kinks

- indicates bending stress

- increased load on tendon

prior to bicep tendon tearing...

attempts to heal itself by forming new fixation to bone by growing into periosteum

if bicep tendon completely ruptures, strength of shoulder abduction decreases approx.

20%

brachialis

muscles that lies deep to the biceps

brachialis

main and only pure flexor of the forearm

brachialis

can act during both slow and quick movements and in the presence or absence of resistance

when the forearm is extended slowly, the ____ steadies the movement by slowly relaxing (eccentric)

brachialis

brachialis

workhorse of the elbow

brachialis

flexes the forearm in all positions, being unaffected by pronation or supination

coracobrachialis

located in superomedial part of the arm, deep to the short head of biceps and has same function

the musculocutaneous nerve pierces

coracobrachialis

coracobrachialis

helps flex, adduct arm, and stabilizes GH joint

shunt muscle

resists downward dislocation of the head of humerus, as when carrying a heavy suitcase (ex. coracobrachialis)

the ____ nerve and/or ____ artery may run deep to the coracobrachialis and be compressed by it

median; brachial

forearm extensors are supplied by

radial nerve

____ and ____ of the forearm do not affect triceps operation

pronation; supination

sub-tendinous olecranon bursa

proximal to the distal attachment of the triceps between the triceps tendon and olecranon

long head of triceps

- aids in extension and adduction of arm

- stabilizes adducted GH

- acts as shunt, resisting inferior displacement of head of humerus

medial head of triceps

- workhorse of forearm extension

- active at all speeds and in presence or absence of resistance

lateral head of triceps

- strongest

- recruited into activity primarily against resistance

anconeous

- small, triangular muscle

- posteriolateral aspect of elbow

- assists triceps in extending forearm

anconeous

tenses the capsule of the elbow join, preventing it being pinched during extension

anconeous may exert ___ force on the ___ during ___ of the forearm

abduction; ulna; pronation

brachial artery

continuation of axillary artery as it passes inferior border of teres major

collateral circulation

allows blood to reach forearm when flexion of elbow compromises flow through the terminal part of brachial artery

the brachial artery provides the main arterial supply to the arm and is the continuation of the ___

axillary artery

the brachial artery begins at the ___ and ends in the ___ opposite the neck of the radius

superficial veins of the arm

supply the skin, cephalic and basilic

deep veins of the arm

accompany the arteries

nerves that innervate the arm

- musculocutaneous

- radial

- medial cutaneous

____ nerve runs between biceps and brachialis

musculocutaneous

branches of the musculocutaneous nerve

supply radial side of forearm

radial nerve travels with

profunda brachial artery

radial nerve supplies

- triceps

- brachioradialis

- extensor muscles of the hand and fingers

branches of radial nerve

- posterior cutaneous n. of arm

- posterior cutaneous n. of forearm

median nerve

supplies articular branches to the elbow joint

the median nerve descends into the cuboid fossa, where it lies deep to...

- bicipital aponeurosis

- median cubital vein

ulnar nerve (C7-T1)

funny bone

___ and ___ nerves do not supply musculature or skin in the arm

median; ulnar