Arm Flashcards
Anatomically where is the arm?
The upper half of the upper limb, between the shoulder and the antecubital fossa
What are the three heads of triceps brachii?
Caput longum (long head), caput mediale (medial head), caput laterale (lateral head)
What are the origins of triceps brachii?
Long head: infraglenoid tubercle
Medial head: posterior humerus - inferior to radial nerve
Lateral head: posterior humerus - superior to radial nerve
What is the insertion of triceps brachii?
Olecranon of the ulna
What is the innervation to triceps brachii?
Radial nerve (C6-8) except lateral head which is axillary nerve (C5,6)
What is the blood supply to the triceps brachii?
Brachial artery profunda
What are the actions of triceps?
extension at the elbow, and extension and adduction at the shoulder
What are the nerve roots of the radial nerve?
C5-T1
Which muscles does the radial nerve innervate?
Triceps brachii and extensor muscles of the forearm
Which part of the upper limb does the radial nerve provide sensation to?
Posterior arm and forearm, lateral aspect of dorsum of the hand, lateral 3 and 1/2 digits
Which artery is the brachial artery a continuation of?
The axillary artery
Does the brachial artery lie anterior or posterior to the humerus?
Anterior
Where is the radial groove?
On the posterior aspect of the humerus, running obliquely from medial to lateral
Where does the radial nerve bifurcate?
At the anterior aspect of the antecubital fossa
Where does the brachial plexus come out of the neck?
Between the anterior and middle scalene muscles
Which veins converge to form the axillary vein?
Brachial and basilic veins
Which vein does the axillary vein drain into?
The subclavian vein
At what landmark does the axillary vein start?
The lower border of teres major
Which vein does the cephalic vein drain into?
The axillary vein
Where does the cephalic vein drain into the axillary vein?
Beneath the scapula at the level of the 1st rib
Which branch comes off the axillary artery in the first segment?
Superior thoracic artery
Which branches come off the axillary artery in the second segment?
Thoracoacromial artery, lateral thoracic artery
Which branches come off the axillary artery in the third segment?
Subscapular artery (circumflex scapular and thoracodorsal), posterior circumflex humoral, anterior circumflex humoral
What defines the parts of the axillary artery?
1st: from 1st rib to medial border of pec minor
2nd: behind pec minor
3rd: lateral border of pec minor to superior border of teres major
Where does the axillary artery become the brachial artery?
At the inferior border of teres major
What is the mneumonic to remember the branches of the axillary artery?
Screw the lawyer save a patient
superior thoracic, thoracoacromial, lateral thoracic, subscapular, anterior and posterior circumflex humeral
What are the branches of the axillary artery?
superior thoracic, thoracoacromial, lateral thoracic, subscapular, anterior and posterior circumflex humeral
What are the two main branches of the subscapular artery?
Circumflex scapular and thoracodorsal arteries
Which muscles does the musculocutaneous nerve innervate?
Coracobrachialis, biceps brachii and brachialis
What are the cords of the brachial plexus named in relation to?
The axillary artery
What are the three cords of the brachial plexus?
Medial, posterior and lateral
Which cord of the brachial plexus does the musculocutaneous nerve come from?
The lateral cord
Which nerve pierces coracobrachialis?
The musculocutaneous nerve
Which area of the skin does the musculocutaneous nerve supply?
The anterolateral forearm
Which cords of the brachial plexus is the median nerve derived from?
The medial and lateral cords
Which muscles does the median nerve supply?
The flexor muscles in the forearm (except flexor carpi ulnaris and ulnar head of flexor digitorum profundus), muscles of the thenar eminence and radial two lumbricals
Which area of the skin does the median nerve supply?
Palm, lateral 3 and 1/2 digits
Which cord of the brachial plexus forms the ulnar nerve?
The medial cord
Which muscles does the ulnar nerve supply?`
Flexor carpi ulnaris, medial half of flexor digitorum profundus, intrinsic muscles of the hand except LOAF
What does LOAF stand for?
Lateral two lumbricals, opponens pollicis, abductor pollicis brevis, flexor pollicis brevis
What area of the skin does the ulnar nerve provide sensation to?
The medial 1 and 1/2 fingers, and the medial aspect of the dorsum of the hand
Where does the lateral pectoral nerve arise from?
The lateral cord of the brachial plexus
Where does the medial pectoral nerve arise from?
The medial and lateral cord of the brachial plexus
What are the two terminal branches of the posterior cord of the brachial plexus?
The axillary and radial nerves
Which three smaller branches come off the posterior cord of the brachial plexus?
The upper and lower subscapular nerve and the thoracodorsal nerve
Which three smaller branches come off the medial cord of the brachial plexus?
The medial pectoral nerve, medial brachiocutaneous and the medial antebrachial cutaneous nerve
Which nerve is most likely to be injured by an injury to the glenohumeral joint?
The axillary nerve
What muscles does the axillary nerve supply?
Deltoid, teres minor, lateral head of triceps brachii
Which areas does the axillary nerve provide sensory innervation from?
The glenohumeral joint, skin over the deltoid region
Which muscles does the radial nerve innervate?
Triceps brachii, anconeus, brachioradialis, and the muscles in the extensor compartment of the forearm
Which area of skin does the radial nerve provide sensation to?
posterior arm and forearm, thenar eminence and dorsal aspect of the radial 3 and 1/2 digits
Which muscle does the thoracodorsal nerve supply?
Latissimus dorsi
Which muscle does the upper subscapular nerve innervate?
Subscapularis
Which muscles does the lower subscapular nerve innervate?
Subscapularis and teres major
Which nerve innervates teres minor?
The axillary nerve
Which nerve innervates deltoid?
The axillary nerve
What are the attachments of coracobrachialis?
O: coracoid process of the scapula
I: Anteromedial surface of the humeral shaft
What is the action of coracobrachialis?
Adduction and flexion of the arm at the shoulder joint
What is the innervation to coracobrachialis?
Musculocutaneous nerve
What are the attachments of brachialis?
O: Distal half of the anterior surface of the humerus
I: coranoid process of the ulna, ulna tuberosity
What is the action of brachialis?
Flexion of the forearm at the elbow joint
What is the innervation to brachialis?
musculocutaneous (C5,6) and radial nerve (C7)
Which muscle makes up the floor of the cubital fossa?
Brachialis
What are the three muscles of the anterior compartment of the arm?
Biceps brachii, brachialis, coracobrachialis
What are the origins of biceps brachii?
Long head: supraglenoid tubercle of the scapula
Short head: coracoid process of the scapula
What are the insertions of biceps brachii?
Radial tuberosity of the forearm and the deep fascia of the forearm
Which nerve supplies biceps brachii?
Musculocutaneous
What is the clinical significance of the bicipital aponeurosis?
It protects the brachial artery and median nerve in phlebotomy
What is the bicipital aponeurosis?
A fibrous band from the inferior part of the biceps tendon running transversely across the ulna to merge with the deep fascia. attaches to radius
What are the five main terminal branches of the brachial plexus?
Musculocutaneous, axillary, radial, median, ulnar nerve
Which muscle does the musculocutaneous nerve pass through?
Coracobrachialis
What is the path of the median nerve?
Down the anterior arm passing between the tendons of biceps brachii and brachialis, into the forearm passing between the heads of pronator teres and through the carpal tunnel
What is the path of the ulnar nerve?
passes along the medial aspect of the arm, passing behind the medial epicondyle in the groove for ulnar nerve, it then moves into the ulnar side of the anterior compartment and into the hand
What are the two main branches of the brachial artery?
The radial and ulnar arteries
Where does the brachial artery bifurcate?
Just below the cubital fossa
Where do the radial and ulnar collateral branches come off?
The brachial artery, they come off 1/3 down the humerus and anastamose with the radial and ulnar branches respectively
What are the four main veins that drain the forearm?
Radial veins, ulnar veins, basilic and cephalic veins
What is the vein that crosses the cubital fossa?
Median cubital vein
What are the two main veins that drain the arm?
The basilic (bottom) and cephalic (most superior) veins
What does the basilic vein drain into?
The axillary vein
What does the cephalic vein drain into?
The axillary vein
What are the nerve roots to biceps brachii?
C5, C6 - pick up sticks
What are the nerve roots to deltoid?
C5,6
What are the nerve roots to triceps?
C4,C5
What are the nerve roots to hand muscles?
C8, T1
Which ligament keeps the head of the radius connected to the radial notch of the ulna?
The annular ligament
Which structure separates the ulnar artery from the median nerve?
Pronator teres
What is the secondary function of biceps brachii?
Supinator
What muscle is considered to be the initiator of abduction in the arm?
Supraspinatus
