Upper Extremities Innervation and Vasculature

Flashcards about Upper Extremities Innervation and Vasculature

Axilla

Space inferior to the glenohumeral joint and superior to axillary fascia at the junctions of UL and thorax. Provides protected passage for the neurovascular structures supplying the UL

Apex of the Axilla

Cervico-axillary canal

Base (axillary fossa)

Skin, superficial and deep (axillary) fascia extending from the arm to the thorax

Anterior wall of the Axilla

Pectoralis major and minor muscles and their associated fascias (pectoral and clavipectoral, anterior axillary fold

Posterior wall of the Axilla

Scapula and subscapularis muscle, posterior axillary fold

Medial wall of the Axilla

Thoracic wall and serratus anterior

Lateral wall of the Axilla

Intertubercular groove of humerus

Brachial Plexus

Network of nerves that innervates most of the UL.

Roots of the Brachial Plexus

Anterior rami of C5-T1 that pass through anterior and middle scalene muscles

Trunks of the Brachial Plexus

Union of the roots in the inferior part of the neck; Superior: C5+C6 roots, Middle: continuation of C7 root, Inferior: C8 + T1 roots

Divisions of the Brachial Plexus

Separation of the trunks as they pass the cervico-axillary canal; Anterior: supply anterior (flexors) compartments of the UL; Posterior: supply posterior (extensor) compartments of the UL

Cords of the Brachial Plexus

Formed by the divisions of the trunks around axillary artery at coracoid process; Labeled in reference to their position around the axillary artery: Posterior, Lateral, Medial

Branches of the Brachial Plexus

Form 2-4 inches of the lateral border of pectoralis minor muscle

Dorsal Scapular Nerve (C4-C5)

Pierces middle scalene and descends middle to levator scapulae and rhomboids; Supply rhomboids and levator scapulae

Long Thoracic Nerve (C5-C7)

Passes through cervico-axillary canal, descends posterior to C8 and T1 roots of brachial plexus, runs on superficial surface of serratus anterior; Supply serratus anterior

Suprascapular Nerve (C5-C6)

Runs across lateral cervical region, through scapular notch; Supply supraspinatus and infraspinatus muscles, glenohumeral joint

Subclavian Nerve (C5-C6)

Supply subclavius muscle

Lateral Pectoral Nerve (C5-C7)

Reaches pectoralis major muscle on its deep surface; Supply pectoralis major muscle

Medial Pectoral Nerve (C8-T1)

Pierces pectoralis minor muscle to get to deep surface of pectoralis major muscle; Supply skin on medial side of arm; Communicates with intercostobrachial nerve (T2)

Medial Cutaneous Nerve of Forearm (C8-T1)

Runs initially with ulnar nerve and pierces deep fascia to enter subcutaneous tissue; Supply skin on medial side of forearm

Medial Cutaneous Nerve of Arm (C8- T1)

Runs along medial side of axillary and brachial veins; Supply skin on medial side of arm; Communicates with intercostobrachial nerve (T2)

Upper Subscapular Nerve (C5-C6)

Runs posteriorly towards the subscapularis muscles; Supply subscapularis muscle

Lower Subscapular Nerve (C5-C6)

Runs inferolaterally towards subscapularis muscle; Supply subscapularis muscle and teres major muscle

Thoracodorsal Nerve (C6-C8)

Runs inferolaterally along posterior axillary wall; Supply latissimus dorsi muscle

Axillary Nerve (C5-C6)

Exits axillary fossa posteriorly and wraps around surgical neck of humerus deep to the deltoid muscle; Supply teres minor and deltoid muscles, glenohumeral joint, and skin on superolateral arm

Radial Nerve (C5-T1)

Runs posterior to humerus in radial groove, perforates lateral intermuscular septum, enters cubital fossa; Supply all muscles of posterior compartments of the arm and forearm, and skin on posterior and inferolateral arm, posterior forearm, and dorsum of hand

Musculocutaneous Nerve (C5-C7)

Exits axilla by piercing the coracobrachialis muscle, descends between biceps and brachialis muscles, continues as lateral cutaneous nerve of forearm; Supply muscles in anterior compartment of arm, and skin on lateral forearm

Ulnar Nerve (C7-T1)

Descends in arm passing posterior to medial epicondyle of humerus, descends on the ulnar aspect of forearm to the hand; Supply FCU, FDP, intrinsic muscles of hand, and skin on medial side of hand (5th digit and medial side of 4th digit)

Median Nerve (C5-T1)

Descends through the arm next to the brachial artery, crosses the elbow joint anterior to the medial epicondyle, enters hand through the carpal tunnel; Supply muscles of anterior compartment of forearm (except FCU and part of FDP) and the thenar region, and skin over lateral side of hand

Suprascapular Artery

Supplies lateral dorsal part of scapula and associated muscles

Dorsal Scapular Artery

Supplies medal dorsal region of scapula and associated muscles

Axillary Artery

Begins at lateral border of 1st rib as a continuation of the subclavian artery, passes posterior to the pectoralis minor muscle, and ends at the inferior border of the teres major muscle (becomes brachial artery)

1st part of the Axillary Artery

Between lateral border of 1st rib and medial border of pectoralis minor muscle

2nd part of the Axillary Artery

Posterior to pectoralis minor muscle

3rd part of the Axillary Artery

Between lateral border of pectoralis minor muscle and inferior border of teres major muscle

Superior Thoracic Artery

Runs anteromedially along pectoralis minor muscle to the thoracic wall; Supply 1st and 2nd intercostal spaces and serratus anterior muscle

Thoracoacromial Artery

Trunk providing the chest and shoulder regions

Lateral Thoracic Artery

Descends along lateral border of pectoralis minor muscle to the thoracic wall; Supply serratus anterior muscles and lateral aspect of breast

Subscapular Artery

Largest branch of axillary artery that descends along lateral border of the subscapularis muscle

Circumflex Scapular Artery

Curves posteriorly around lateral border of scapula and supplies muscles on dorsum of scapula

Thoracodorsal Artery

Descends to the inferior angle of the scapula supplying muscles in the region, particularly the latissimus dorsi

Anterior and Posterior Circumflex Arteries

They encircle the surgical neck of the humerus, anastomosing laterally with each other; Supply glenohumeral joint and surrounding muscles

Brachial Artery

Continuation of the axillary artery that begins at the inferior border of teres major, runs in the arm medial to the humerus and enters the forearm lateral to the median nerve/deep to the bicipital aponeurosis to end in the cubital fossa, dividing into radial and ulnar arteries

Deep Artery of Arm

Most superior and largest branch of brachial artery that runs with radial nerve in radial groove

Humeral Nutrient Artery

Arises around middle of arm enters nutrient canal on humerus and supplies the bone marrow

Superior Ulnar Collateral Artery

Descends in the arm towards the elbow, accompanying the ulnar nerve posterior to the medial epicondyle; Participates in arterial anastomose around elbow

Inferior Ulnar Collateral Artery

Descends in the arm towards the elbow anterior to medial epicondyle; Participates in arterial anastomose around elbow

Cubital Fossa

Triangular space on anterior aspect of elbow

Superior Boundary of Cubital Fossa

Imaginary line connecting medial and lateral epicondyles

Medial Boundary of Cubital Fossa

Flexors (pronator teres muscle)

Lateral Boundary of Cubital Fossa

Extensors (brachioradialis muscle)

Floor of Cubital Fossa

Supinator muscle

Roof of Cubital Fossa

Bicipital aponeurosis

Ulnar Artery

Largest terminal branch of the brachial artery that arises opposite to the neck of the radius in the inferior part of cubital fossa, runs inferiorly lateral to the ulnar nerve, and is superficial to flexor retinaculum when it enters the hand

Common Interosseous Artery

Runs laterally and deeply, and quickly divides

Anterior Interosseous Artery

Runs on anterior aspect of interosseous membrane, pierces the membrane distally to pass posteriorly and join the dorsal carpal arch

Posterior Interosseous Artery

Runs on posterior aspect of interosseous membrane and is replaced distally by the anterior interosseous artery

Palmar Carpal Branch

Runs across anterior aspect of wrist to anastomose with palmar carpal branch of radial artery to form the palmar carpal arch

Dorsal Carpal Branch

Runs across dorsal aspect of wrist to anastomose with dorsal carpal branch of radial artery to form the dorsal carpal arch

Radial Artery

Smallest terminal branch of the brachial artery that arises opposite the neck of the radius in the inferior part of cubital fossa, runs inferiorly and on distal part lies on top of radius (making it easy to check the radial pulse)

Superficial Palmar Branch of Ulnar Artery

Main termination of ulnar artery that forms the superficial palmar arch

Deep Palmar Branch of Ulnar Artery

Anastomoses with the deep palmar arch of the radial artery

Superficial Palmar Branch of Radial Artery

Main termination of radial artery that forms the superficial palmar arch

Deep Palmar Branch of Radial Artery

Termination of radial artery that forms deep palmar arch

Deep Venous Drainage

Lie internal to deep fascia; Travel with and bear the same name as the major arteries of the upper limbs

Dorsal Venous Network

Formed on the dorsum of hand from digital and metacarpal veins

Perforating Veins

Form communications between deep and superficial veins

Cephalic Vein

From lateral aspect of dorsal venous network, along lateral border of wrist and anterolateral surface of forearm and arm, runs in the delto-pectoral groove, joins terminal part of axillary vein; Communicates with the median cubital vein

Median Cubital Vein

Runs obliquely in the cubital fossa and communicates the cephalic and basilic veins

Basilic Vein

From medial aspect of dorsal venous network, along medial side of forearm and arm, goes deep and joins the accompanying veins of the brachial artery to form the axillary vein

Median Antebrachial Vein

From base of dorsum of thumb, curves around lateral side of wrist, ascends in the anterior aspect of forearm between cephalic and basilic veins

Axillary Vein

Starts at the inferior border of the teres major muscle, runs anterior to the axillary artery, ends at the lateral border of the 1st rib, where it becomes the subclavian vein; Formed from brachial vein and basilic vein

Superficial Lymphatic Vessels

Originate from lymphatic plexuses in the skin of fingers, palm, and dorsum of hand, ascends with the superficial veins, end in the axillary lymph nodes

Deep Lymphatic Vessels

Less abundant than the superficial lymphatic vessels and accompany deep veins, end in the axillary lymph nodes; Drain joint capsules, tendons, nerves, and muscles