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Flashcards in Arm Deck (19):

brachial artery

provides main arterial supply to arm and is continuation of axillary artery
begins at inferior border of teres major and ends in cubital fossa opposite neck of radius under cover of bicipital aponeurosis where it divides into radial and ulnar arteries
relatively superficial and palpable
anterior to triceps and brachialis
at first: medial to humerus where pulsations are palpable in medial bicipital groove
then passes anterior to medial supra-epicondylar ridge and trochlea of humerus
as it passes inferolaterally, brachial artery accompanies median nerve, which crosses nateriorly
give rise to profunda brachii artery and superior and inferior ulnar collateral arteries


superficial veins of arm

cephalic nd basilic veins: go to axillary


brachial vein

paired deep veins collectively constitute it
acoompany brachial artery
begins at elbow by union of accompanying veins of ulnar and radial arteries
ends by merging with basilic vein to form the axillary vein


four main nerves passing through arm

median, ulnar, musculocutaneous, and radial


median nerve

formed in axila by union of medial and lateral roots from medial and lateral cords of brachial plexus
runs distally in arm, initially on lateral side of brachial artery until it reaches the middle of the arm, where it croses to the medial side and contacts the brachialis
then descends into cubital fossa, where it lies deep to bicipital aponeurosis and median cubital vein


ulnar nerve

arises from medial cord of brachial plexus, C8 and T1
psses distally, anterior to insertion of teres major and to long head of triceps, on medial side of brachial artery
around the middle of arm, pierces medial intermusculr septum with the superior ulnar collateral artery and descends between septum and medial head of triceps
passes posterior to medial epicondyle of the humerus to enter the forearm


musculocutaneous nerve

arises from lateral cord of brachial plexus, pierces coracobrachialis and then continues distally between the brachialis and the biceps
after supplying all three muscles of anterior compartment of arm, the nerve emerges lateral to the biceps brachii as the lateral cutaneous nerve of the forearm


radial nerve

enters arm posterior to brachial artery, medial to humerus and anterior to long head of triceps
descends inferolaterally with profunda brachii artery and curves around the humeral shaft in the radial groove
pierces the lateral intermuscular septum and continues inferiorly in the anterior compartment between brachialis and brachioradialis
in the cubital fossa, it divides into deep and superficial branches
supplies muscles in posterior compartments of the arm and forearm and the overlying skin


cubital fossa

shallow triangular depression on anterior surface of elbow
superiorly: imaginary line connecting medial and lateral epicondyles
medially:pronator teres
laterally: brachioradialis
floor: brachialis and supinator muscles
roof: continuity of brachial and antebrachial (deep) fascia, reinforced by the bicipital aponeurosis, subcutaneous tissue and skin


contents of cubital fossa

terminal part of brachial artery and commencement of its terminal branches (radial and ulnar arteries); brachial artery lies between biceps tendon and median nerve
deep accompanying veins of arteries
biceps brachii tendon
median nerve
radial nerve (dividing into superficial and deep branches)


subcutaneous tissue overlying cubital fossa contains

median cubital vein: lies anterior to brachial artery
medial and lateral cutaneous nerves of forearm: related to basilic and cephalic veins


biceps tendinitis

usually result of repetitive microtrauma in throwing sports
tendon of long head of biceps, enclosed by synovial sheath, moves back and forth in intertubercular sulcus


rupture of tendon of long head of biceps

usually result of biceps tendinitis
normally torn from attachment to supraglenoid tubercle of scapula
snap or pop
detached muscle belly forms a ball near the center of the distal part of anterior aspect of arm: Popeye deformity


bicipital myotatic reflex

relaxed limb passively supinated and partially extended at elbow
examiners thumb placed firmly on biceps tendon, hammer tapped at base of nail bed of thumb
positive response: flexion of elbow: confirms integrity of musculocutaneous nerve and C5 and C6 segments


injury to musculocutaneous nerve

in axilla: usually inflicted by weapon like knife
results in paralysis of coracobrachialis, biceps and brachialis
flexion of elbow and supination of forearm greatly weakened
loss of sensation may occur on lateral surface of forearm supplied by lateral cutaneous nerve of forearm


injury to radial nerve

superior to origin of its branchesto triceps brachii results in paralysis of triceps, brachioradialis, supinator and extensor muscles of wrist and finges
loss of sensation ocurs in skin
when injured in radial groove: triceps not completely paralyzed but weakened b/c only medial head affected, but other muscles paralyzed
wrist drop


occulsion or laceration of brachial artery

emergency because paralysis of muscles results from ischemia in only a few hours
after this, fibrous scar tissue develops and causes involved muscles to shorten permanently: Volkmann ischemic contracture: flexion deformity
flexion of fingers and sometimes wrist results in loss of hand power


measuring blood pressure

cuff placed around arm and compresses brachial artery
stethoscope placed over artery in cubital fossa
cuff released and examiner detects sound of blood beginning to spurt through artery
first audible spurt: systolic blood pressure
as pressure completely released:point at which can no longer be heard: diastolic blood pressure


compression of brachial artery

best place is near middle of arm
biceps pushed laterally to detect pulsations of artery
must be clamped distal to inferior ulnar collateral artery without producing tissue damage
ulnar and radial still receive blood through anastomoses