Neurovasculature of the upper limbs

Last updated: March 22, 2022

Summary

The arteries of the upper limb arise from the subclavian artery, a branch of the aortic arch. At the outer border of the 1^st rib, the subclavian artery continues as the axillary artery, which is the main artery of the axillary fossa. At the inferior border of the teres major, the axillary artery continues as the brachial artery, the main artery of the arm. The brachial artery divides at the cubital fossa into the radial and ulnar arteries, the main arteries of the forearm and hand. The venous system of the upper limbs can be divided into a superficial and deep venous system. The cephalic vein, basilic vein, and medial antebrachial vein comprise the superficial venous system, which drains into the deep venous system. The deep veins accompany the arteries of the upper limbs and drain into the axillary vein; this continues as the subclavian vein and drains into the superior vena cava. The upper limb is innervated by nerves of the brachial plexus, a somatic neural network formed by the anterior branches of the spinal nerves C5–T1. The musculocutaneous, axillary, radial, ulnar, and median nerves are the most important sensorimotor nerves of the upper limb.

Overview

Upper extremity (complete): interactive 3D Model

Arteries

The upper limb is supplied by the axillary artery, which receives blood from the thoracic aorta via the subclavian artery and its branches.

Arteries of the upper extremity

Axillary artery ^[1]^[2]

Origin: continuation of the subclavian artery at the outer border of the 1^strib
Course
- Continues as the brachial artery at the outer border of the teres major
- Divided into 3 parts by the overlying pectoralis minor muscle
  - 1^st part: proximal to the pectoralis minor
  - 2^nd part: inferior to the pectoralis minor
  - 3^rd part: distal to the pectoralis minor
Anatomical relations: In the axilla, it lies lateral to the axillary vein and is bordered inferiorly by the brachial plexus cords.
Area of supply: lateral thoracic wall, upper limb, and axilla

Branches of the axillary artery

Overview of branches of the axillary artery
Vessel	Origin	Course	Area of supply
Superior thoracic artery	1^st part	Runs anteromedially along the superior border of the pectoralis minor before passing between it and the pectoralis major to reach the thoracic wall Forms anastomoses with the intercostal arteries and the internal thoracic artery	1^st and 2^nd intercostal muscles Superior part of the serratus anterior muscle Pectoral muscles Subclavius muscle Skin of the thoracic wall
Thoracoacromial artery (thoracoacromial trunk)	2^nd part (first branch)	Runs posterior to the pectoralis minor muscle before piercing the clavipectoral fascia Divides into four branches: Pectoral branch Deltoid branch Acromial branch Clavicular branch	Pectoral muscles Deltoid muscle Skin overlying the clavipectoral fascia
Lateral thoracic artery	2^nd part (second branch)	Descends along the axillary border of the pectoralis minor	Lateral structures of the thorax and the breast
Anterior humeral circumflex artery	3^rd part	Passes laterally deep to the coracobrachialis and biceps brachii muscles Gives off an ascending branch, which runs inside the intertubercular sulcus Forms anastomoses with the posterior humeral circumflex artery lateral to the humerus	Glenohumeral joint Teres major, teres minor, triceps, and deltoid muscles
Posterior humeral circumflex artery		Passes through the quadrangular space together with the axillary nerve Gives off a descending branch Forms anastomoses with the anterior humeral circumflex artery lateral to the humerus
Subscapular artery		Descends along the lateral border of the subscapularis on the posterior axillary wall Divides into the thoracodorsal artery and the circumflex scapular artery	3 Rotator cuff muscles: Subscapularis Infraspinatus Supraspinatus Deltoid muscle Latissimus dorsi muscle Long head of triceps brachii muscle Serratus anterior muscle Adjacent skin

Scapular anastomosis ^[2]

Definition: an anastomosis between the branches of the first part of the subclavian artery and the third part of the axillary artery that provides collateral circulation to the arm in case of occlusion or injury to the axillary or subclavian arteries

Overview of scapular arteries
Artery	Origin	Location
Dorsal scapular artery	Thyrocervical trunk or a direct branch of the subclavian artery	Medial border of the scapula
Suprascapular artery		Supraspinous fossa of the scapula
Circumflex scapular artery	Subscapular artery	Infraspinous fossa of the scapula
Subscapular artery	3^rd part of the axillary artery	Lateral border of the scapula
Intercostal arteries	Subclavian artery or the descending thoracic aorta	Multiple anastomoses with the dorsal scapular artery at the medial border of the scapula

Brachial artery ^[1]^[2]

Origin: continuation of the axillary artery at the inferior border of the teres major
Course
- Passes from the medial aspect of the humerus to the anterior aspect of the arm
- Terminates at/just below the cubital fossa by bifurcating into the radial and ulnar arteries
Anatomical relations
- Close location to the humerus allows blood pressure and pulse measurement.
- The median nerve lies laterally and the ulnar nerve lies medially at the teres major border.
Area of supply: coracobrachialis, biceps, and triceps brachialis muscles along with the elbow joint and overlying skin

Overview of branches of the brachial artery
Vessel	Course	Area of supply
Deep artery of arm (profunda brachii)	Main branch of the brachial artery Accompanies the radial nerve in the radial groove, within the triangular interval of the axilla Further divides into the medial and radial collateral arteries	Supplies the brachialis, brachioradialis, and contributes to the elbow anastomosis Ensures collateral circulation to the arm and forearm in case of proximal brachial artery injury
Superior ulnar collateral artery	Accompanies the ulnar nerve	Contributes to the elbow anastomosis
Inferior ulnar collateral artery	Passes medially down the brachialis muscle, anterior to the medial epicondyle Gives branches to the superior ulnar collateral artery and anterior ulnar recurrent artery	Contributes to the elbow anastomosis
Middle ulnar collateral artery	Arises between the superior and inferior ulnar collateral arteries	Ensures collateral circulation to the skin by giving off perforator arteries
Nutrient artery of the humerus	Arises at the middle of the arm Enters the humerus posterior to the deltoid tuberosity	Humerus

The brachial artery can be compressed proximally against the medial humerus to stop bleeding in the distal arm.

The deep artery of the arm ensures collateral circulation through the elbow anastomosis in case of proximal brachial artery injury. Disruption of the brachial artery distal to the origin of the deep artery of the arm is associated with a greater degree of ischemia of the upper limb.

Radial artery

Origin: terminal branch of the brachial artery
Course
- Begins at/just below the cubital fossa
- Passes deep to the brachioradialis
- Descends along the ventrolateral aspect of the forearm, dorsally at the wrist
- Pierces the first dorsal interosseous muscle to enter the palm
- Anastomoses with branches of the ulnar artery to form the carpal arches
Anatomical relations
- Running laterally at the forearm and its location at the wrist allows for pulse and heart rate measurement.
- The radial artery courses dorsally at the wrist and passes through the anatomical snuffbox.
Area of supply: supplies the elbow, wrist, hand, and the posterolateral aspect of the forearm

Overview of branches of the radial artery
Vessel	Course	Area of supply
Radial recurrent artery	Originates distal to the radial artery bifurcation from the brachial artery, at the cubital fossa Anastomoses with the radial collateral artery	Contributes to the elbow anastomosis
Palmar carpal branch	Originates near the border of the pronator quadratus muscle Runs anteriorly to the carpal bones Anastomoses with: The palmar carpal branch of the ulnar artery The anterior interosseous arteries Forms the palmar carpal arch	Carpal bones
Dorsal carpal branch	Originates proximal to the anatomical snuffbox, distal to the radial styloid Runs medially across the wrist Anastomoses with: The dorsal carpal branch of the ulnar artery The posterior interosseous arteries Forms the dorsal carpal arch	Carpal bones
Superficial palmar branch	Originates from the medial aspect of the radial artery over the radial styloid Lies between the long flexor tendons of the digits and the palmar aponeurosis Forms the superficial palmar arch by anastomosing laterally with the superficial palmar branch of the ulnar artery	Phalanges of digits two through four Metacarpophalangeal joints of digits two through four Interphalangeal joints of digits two through four
Deep palmar branch	Lies between the long flexor tendons of the digits and the bases of the metacarpal bones Forms the deep palmar arch by anastomosing medially with the deep palmar branch of the ulnar artery	Carpal bones Metacarpal bones Muscles: adductor pollicis, interossei, and lumbrical muscles Metacarpophalangeal joints Proximal interphalangeal joints Radioulnar joint
First dorsal metacarpal arteries	Originates at the palmar aspect of the first intermetacarpal space Divides into three branches: radial, intermediate, and ulnar	Radial branch to the thumb Intermediate branch to the first web space Ulnar branch to the second digit
Radialis indicis artery (radial artery of the index finger)	Originate at the webspace between the thumb and index finger Run across the dorsal aspect of the hand	Radial (lateral) aspect of the second digit
Princeps pollicis (principal artery of the thumb)		The thumb

Anatomical snuff box Modified Allen test

The Allen test evaluates patency of the collateral circulation to the hand through the radial and ulnar arteries.

Ulnar artery

Origin: terminal branch of the brachial artery
Course
- Begins at/just below the cubital fossa
- Descends along the ulnar (medial) aspect of the forearm
- Passes superficial to the flexor retinaculum at the wrist
- Courses through the Guyon canal to enter the hand
- Anastomoses with branches of the radial artery form the carpal arches
Anatomical relations
- Separated by the pronator teres muscle from the median nerve
- At the Guyon canal, it passes along with the ulnar nerve
Area of supply: supplies the medial forearm, wrist and hand

Overview of branches of the ulnar artery
Vessel		Course	Area of blood supply
Ulnar recurrent arteries	Anterior	Proximal branch of the ulnar artery that runs anteriorly and superiorly to the medial humeral epicondyle	Contribute to the elbow anastomosis
Ulnar recurrent arteries	Posterior	Proximal branch of the ulnar artery, which originates distally to the anterior ulnar recurrent artery Runs posteriorly and anteriorly to the medial humeral epicondyle	Contribute to the elbow anastomosis
Common interosseous artery		Originates at the forearm Divides immediately into the anterior and posterior interosseous arteries Runs through the interosseus membrane of the forearm	Anterior interosseus artery: deep muscles of the flexor compartment of the forearm, radius, and ulna Posterior interosseous artery: extensor muscles of the forearm
Palmar carpal branch		Originates at the carpus beneath the tendons of the flexor digitorum profundus Anastomoses with the corresponding branch of the radial artery	Wrist (carpal bones and joints)
Dorsal carpal branch		Originates at the pisiform bone beneath the tendon of the flexor carpi ulnaris Runs dorsally across the carpus beneath the extensor tendons Anastomoses with the corresponding branch of the radial artery	Wrist (carpal bones and joints) Ulnar side of the dorsal surface of the fifth finger
Deep palmar branch		Originates anterior to the flexor retinaculum of the hand Anastomoses with the terminal branch of the radial artery	Hypothenar muscles Contributes to the deep palmar arch of the hand
Superficial palmar branch		Direct continuation of the ulnar artery in the hand Lies superficially to the intrinsic hand muscles, flexor tendons, and deep to the palmar aponeurosis Anastomoses with the common palmar digital arteries	Ulnar aspect of the index finger and third and fourth digits

Anastomosis within the hand

Dorsal carpal arch: formed by an anastomosis between the dorsal carpal branch of the radial artery and the dorsal carpal branch of the ulnar artery
Palmar carpal arch: an anastomosis between the palmar carpal branch of the radial artery and the palmar carpal branch of the ulnar artery
Superficial palmar arch: formed by the distal ulnar artery and the superficial palmar branch of the radial artery
Deep palmar arch: formed by the distal radial artery and the deep palmar branch of the ulnar artery

Veins

Overview ^[1]

The upper limbs have a superficial and deep venous system that eventually drains into the superior vena cava.
The superficial veins lie within the subcutaneous tissues and drain into the deep venous system.
The deep veins lie deep to the fascia, accompanying the arteries of the upper limb as venae comitantes.
Venous valves ensure the unidirectional flow of blood toward the heart.

Veins of the upper extremity

Overview of veins of the upper limb
Veins	Origin	Course	Termination	Main tributaries	Drains
Superficial veins
Cephalic vein	Lateral (radial) end of the dorsal venous arch at the anatomical snuffbox	Along the lateral aspect of the forearm and arm	Drains into the axillary vein at the deltopectoral groove	Median cubital vein	The palm, lateral forearm, and lateral arm
Basilic vein	Medial (ulnar) end of the dorsal venous arch	Along the medial aspect of the forearm and the arm, passing ventral to the medial epicondyle	Joins the brachial vein (deep vein of arm) at the outer border of the teres major to form the axillary vein	Median cubital vein	The palm, medial forearm, and medial arm
Median antebrachial vein	Palmar venous network of the hand	Along the central aspect of the ventral forearm	Drains into the median cubital vein (most common) or the basilic vein	Small superficial veins of the forearm	The superficial structures of ventral mid-forearm, wrist, and palmar surface of the hand
Median cubital vein	Lies within the subcutaneous tissue of the cubital fossa	Passes diagonally across the roof of the cubital fossa	Connects the cephalic vein with the basilic vein	Median antebrachial vein	The hand, wrist, and forearm
Deep veins
Radial veins	Deep palmar venous arch	Accompany the radial artery	Drain into the brachial vein	Palmar and dorsal metacarpal veins The accompanying veins of branches of the radial artery	The lateral aspect of the forearm and hand
Ulnar veins	Deep palmar arch	Accompany the ulnar artery	Drain into the brachial vein	Associated veins of branches of the ulnar artery	The medial aspect of the forearm and hand
Brachial veins	Formed by the union of the ulnar, radial, and interosseous veins at the cubital fossa	Accompany the brachial artery in the arm	Unite with the basilic vein at the inferior border of the teres major to form the axillary vein	Basilic vein	The arm, forearm, and hand
Axillary vein	Formed by the union of the brachial veins and the basilic vein	Begins at the inferior border of the teres major Passes through the axillary fossa (lies medial to the axillary artery)	At the lateral border of the 1^st rib, where it continues as the subclavian vein	Cephalic vein and tributaries that parallel the branches of the axillary artery Exceptions There is no common tributary for the veins that correspond to the branches of the thoracoacromial trunk. Directly or indirectly receives the thoracoepigastric veins	The upper limb, axilla, shoulder, and superolateral chest wall

Nerves

Overview

Brachial plexus Brachial plexus: interactive 3D Tour

The nerves of the upper limb are derived from the brachial plexus.

Course and composition of the brachial plexus
- Five roots, which are the anterior branches of C5–T1 spinal nerves that merge within the posterior triangle of the neck to form the trunks.
- Three trunks (upper, middle, lower) pass through the scalene triangle, between the anterior and middle scalene muscles
- Six divisions
  - Formed beneath the clavicle as each trunk splits into an anterior and posterior division
  - The divisions then pass into the axillary fossa.
- Three cords (lateral, posterior, and medial)
  - Formed by the merging of the divisions within the axillary fossa
  - The cords lie posterior to the axillary artery.
- Terminal branches arise from the cords and innervate the upper limb, back, and superior thoracic wall.
Functional significance
- Motor innervation: all upper limb and shoulder muscles except for the trapezius, which is supplied by the spinal accessory nerve
- Sensory innervation: the axilla and the upper limb except for the medial portion of the arm, which is supplied by the intercostobrachial nerve

Scalene triangle

Brachial plexus

Definition: a somatic neural network derived from C5–T1 spinal nerves, from which the peripheral nerves of the upper limb arise
Composition: The brachial plexus is composed of roots, trunks, divisions, cords, and branches (proximal to distal).

“Rugby Teams Drink Cool Beer!”: Roots, Trunks, Divisions, Cords, Branches (order of the brachial plexus divisions)

Brachial plexus

Roots

Anterior (ventral) divisions of C5–T1
The roots merge in the posterior triangle of the neck to form the trunks.
The dorsal scapular nerve and long thoracic nerve arise from the roots of the brachial plexus.

Nerves that arise from the roots of brachial plexus
Nerve	Dorsal scapular nerve	Long thoracic nerve
Nerve root	C5	C5–C7
Function	Motor nerve
Course	Passes through the scalenus medius muscle in the region of the lateral neck Courses to the scapula deep to the levator scapulae muscle Courses caudally to the medial border of the scapula	Pierces the scalenus medius muscle Courses caudally to the border of the serratus anterior muscle
Innervation	Levator scapulae muscles Rhomboid major Rhomboid minor	Serratus anterior

Trunks

The roots form three trunks that are located in the neck:
- Upper trunk of the brachial plexus (C5 and C6): The suprascapular and subclavian nerve originate here.
- Middle trunk of the brachial plexus (C7)
- Lower trunk of the brachial plexus (C8 and T1)
The trunks course through the scalene triangle (together with the subclavian artery) and the base of the posterior triangle of the neck to enter the axillary fossa.

Nerves that arise from the upper trunk of brachial plexus
Nerve	Subclavian nerve	Suprascapular nerve
Nerve root	C5–C6	C4–C6
Function	Motor nerve
Course	Short, thin nerve that courses directly to the subclavius muscle	Courses dorsal to the clavicle deep to the trapezius muscle and the superior transverse scapular ligament into the supraspinous fossa From there, it courses along the inferior transverse scapular ligament into the infraspinous fossa
Innervation	Subclavius muscle	Supraspinatus muscle Infraspinatus muscle

Brachial plexus

Divisions

Each trunk divides into an anterior and posterior division that enters the axillary fossa.
All three posterior divisions innervate the extensor compartment of the arm and forearm (i.e., the posterior compartment).
All three anterior divisions innervate the flexor compartment of the arm and forearm (i.e., the anterior compartment).

Cords

The cords and proximal portions of their branches lie in the axillary fossa.
There are three cords, which are named according to their position in relation to the axillary artery:
- Lateral cord of the brachial plexus: formed by the anterior divisions of upper and middle trunks
- Medial cord of the brachial plexus: formed by the anterior division of the lower trunks
- Posterior cord of the brachial plexus: formed by the posterior divisions of all three trunks

Branches ^[2]

Branches are the peripheral nerves that arise from each of the cords of the brachial plexus. The five most clinically significant branches of the brachial plexus are the musculocutaneous, axillary, median, radial, and ulnar nerves.

Lateral cord of the brachial plexus

Lateral cord and branches of the brachial plexus
Branches of the brachial plexus	Spinal roots	Course	Motor innervation	Sensory innervation
Musculocutaneous nerve	C5–C7	Pierces the coracobrachialis muscle Courses between the biceps brachii and the brachialis Continues as the lateral cutaneous nerve of arm	Muscles of the anterior compartment of the arm Biceps Brachialis Coracobrachialis	Lateral aspect of the forearm (via the lateral antebrachial cutaneous nerve of the forearm)
Lateral pectoral nerve		Passes anterior to the axillary artery Sends a branch to the medial pectoral nerve Pierces the clavipectoral fascia Terminates by supplying the pectoralis major	Pectoralis major Sometimes the pectoralis minor	None
Lateral root of median nerve		The largest terminal branch of the lateral cord Passes medially to join a similar branch from the medial cord to form the median nerve	Forearm: all flexors (anterior compartment) except for those supplied by the ulnar nerve Hand: thenar muscles and lateral two lumbricals	Radial ⅔ of the palm Palmar aspect of the radial 3 ½ fingers (i.e., the thumb, index finger, middle finger, and radial side of the ring finger) Dorsal aspect of the distal phalanges of the radial 3 ½ fingers Autonomous sensory zone: tip of the index finger

Sensory innervation areas of the peripheral nerves (arm, ventral view) Musculocutaneous nerve Median nerve: interactive 3D Tour

Medial cord of the brachial plexus

Medial cord and branches of the brachial plexus
Branches of the brachial plexus	Spinal roots	Course	Motor innervation	Sensory innervation
Medial root of median nerve	C8–T1	Courses between the biceps and the triceps in the arm Passes through the cubital fossa, flanked by the biceps tendon and the brachial artery Enters the forearm by passing between the two heads of the pronator teres Courses along the forearm between the flexor digitorum superficialis and flexor digitorum brevis Passes through the carpal tunnel, beneath the flexor retinaculum, to enter the wrist Terminates by dividing into digital nerves	Same as for the lateral root	Same as for the lateral root
Medial pectoral nerve		Passes posterior to the axillary artery Pierces through the pectoralis minor Terminates by supplying the pectoralis major	Pectoralis major Pectoralis minor	None
Medial brachial cutaneous nerve (medial cutaneous nerve of arm)		Courses medial to the axillary and brachial veins Becomes superficial at the mid-arm by piercing the deep fascia	None	Inferomedial aspect of the arm
Medial antebrachial cutaneous nerve (medial cutaneous nerve of forearm)		Becomes superficial at the mid-arm by piercing the deep fascia Accompanies the basilic vein in the forearm and distal arm	None	Skin over the medial forearm
Ulnar nerve		Courses medial to the axillary artery within the medial bicipital groove Courses dorsally at the medial upper arm, where it perforates the medial intermuscular septum and enters the posterior (extensor) compartment Courses within the groove for the ulnar nerve around the ulnar joint (gives off the articular branches and the muscular branches) Passes through the cubital tunnel back to the flexor aspect of the arm (gives off the dorsal branch and the cutaneous palmar branch) Divides above the wrist into its terminal branches (superficial branch and deep branch)	Forearm: flexor carpi ulnaris and the medial half of the flexor digitorum profundus Hand: intrinsic muscles of the hand except for the thenar muscles and two lateral lumbricals	Palmar and dorsal aspects of the medial side of the hand Palmar and dorsal aspects of the ulnar 1 ½ fingers (i.e., the little finger and the ulnar side of the ring finger) Autonomous sensory zone: tip of the little finger

Branches from the medial and lateral cords form the median nerve.

Median nerve Ulnar nerve

Posterior cord of the brachial plexus

Posterior cord and branches of the brachial plexus
Branches of the brachial plexus	Spinal roots	Course	Motor innervation	Sensory innervation
Upper subscapular nerve	C5	Short course: terminates by supplying the subscapularis muscle	Subscapularis	None
Radial nerve	C5–T1	Dorsal to the axillary artery (gives off muscular branches) Passes through the triangular interval together with the deep brachial artery and vein on the extensor aspect of the upper arm and courses distally within the radial groove (gives off the posterior cutaneous nerve, inferior lateral cutaneous nerve) Punctures the lateral intermuscular septum of arm and courses to the radial tunnel in the cubital fossa (giving off muscular branches, posterior cutaneous nerve of forearm)	Muscles of the posterior compartment of the arm: triceps brachii, anconeus muscles Lateral part of the brachialis muscle Posterior compartment of the forearm	Radial ⅔ of the dorsal aspect of the hand Dorsal aspect of the radial 3 ½ fingers (except the area supplied by the median nerve) Autonomous sensory zone: 1^st web space (between the thumb and index finger)
Axillary nerve	C5-C6	Courses dorsally through the lateral axillary fold Courses around the surgical neck of the humerus Divides into three branches innervating the deltoid muscle Posterior branch ends as the superior lateral cutaneous nerve of arm	Shoulder joint Teres minor Deltoid muscle	Skin of the superolateral arm (over the inferior part of the deltoid muscle)
Lower subscapular nerve	C6–C8	Short course: terminates by supplying the subscapularis muscle Sends a branch to the teres major muscle	Subscapularis Teres major	None
Thoracodorsal nerve	C6	Courses alongside the thoracodorsal vessels along the ventral aspect of the latissimus dorsi muscle	Latissimus dorsi Sometimes the teres major	None

Radial nerve

Clinical significance

Disorders

Procedures

Site for intravenous access or cannulation, especially the median cubital and cephalic veins
Brachial arterial pressure: site for measuring blood pressure
Pectoral nerve block
Brachial plexus block

References

Standring S. Gray's Anatomy: The Anatomical Basis of Clinical Practice. Elsevier Health Sciences ; 2016
Moore KL, Dalley AF, Agur AMR. Clinically Oriented Anatomy. Lippincott Williams & Wilkins ; 2013

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Neurovasculature of the upper limbs

Summary

Overview

Arteries

Axillary artery [1][2]

Branches of the axillary artery

Scapular anastomosis [2]

Brachial artery [1][2]

Radial artery

Ulnar artery

Anastomosis within the hand

Veins

Overview [1]

Nerves

Overview

Brachial plexus

Roots

Trunks

Divisions

Cords

Branches [2]

Lateral cord of the brachial plexus

Medial cord of the brachial plexus

Posterior cord of the brachial plexus

Clinical significance

Disorders

Procedures

References

3 free articles remaining

Axillary artery ^[1]^[2]

Scapular anastomosis ^[2]

Brachial artery ^[1]^[2]

Overview ^[1]

Branches ^[2]