Arteries Of Upper Limb
It is the main artery of upper limb. It begins at the level of outer border of first rib as a continuation of subclavian artery.It ends at the level of lower border of teres major to continue as brachial artery.
The axillary artery is covered anteriorly by Pectoralis minor, which divides it into three parts:-
- First part:- This part is proximal to upper border of Pectoralis minor, i.e. extends from outer border of first rib to upper border of pectoralis minor. The branch of first part is Superior thoracic artery.
- Second part: - This part is behind pectoralis minor. It gives following branches.
- Thoracoacromialartery:-It pierces clavipectoralfascial and gives following branches: - (i) Acromial (ii) Pectoral, (iii) Clavicular and deltoid.
- Lateral thoracic artery
- Third part: - This part is distal to lower border of pectoralis minor, i.e. extends from pectoralis minor (lower border) to teres major (lower border). It gives following branches-
- Subscapular artery: It gives off circumflex scapular arteryand then continues us thoracodorsal artery.
- Anterior circumflex humeral artery.
- Posterior circumflex humeral artery.
Anastomosis around scapula
Anastomosis around scapula connects the first part of subclavian artery with third part of axillary artery. The anastomosis is formed by:-
- Around body of scapula
- Suprascapular (branch of 1 st part of subclavian).
- Deep branch of transverse cervical (branch of Thyrocervical trunk from 1st part of subclavian).
- Circumflex scapular (branch of subscapular, which is a branch of3rd part of axillary).
- On the acromion process
- Acromial branch of Thoracoacromial (branch of 2nd part ofaxillary).
- Ascending branch of posterior circumflex humeral (branch of 3rd part ofaxillary).
- Acromial branch of suprascapular (branch of 1st part of subclavian).
- Anastomosis around scapula provides blood supply to distal part if first or second part of axillary artery is blocked.
It begins as a continuation of axillary artery at level of lower border ofteres major muscles. It terminates in the Cubital fossa, opposite the level of neck of radius by dividing into radial and ulnar arteries. It gives following branches-
- Profundabrachii :- Accompanies radial nerve in the spiral groove and gives following branches-
- Deltoid branch (ascending branch):- It anastomoses with the descending branch of posterior circumflex humeral artery.
- Nutrient artery to humerus: Muscular branches
- Posterior descending (middle collateral):- It anastomoses with interosseous recurrent branch of ulnar artery.
- Anterior descending (radial collateral): It anastomoses with radial recurrent branch of radial artery in front oflateral epicondyle.
- Superior ulnar collateral artery: - Anastomoses with posterior ulnar recurrent branch of ulnar artery behind medial epicondyle.
- Muscular branches
- Inferior ulnar collateral (Supratrochlear artery):- Anastomoses with anterior ulnar recurrent branch of ulnar artery in front of medial epicondyle.
Branches of brachial artery and Profunda brachii arteries anastomoses with recurrent branches of radial and ulnar arteries forming anastomosis around elbow joint.
It is one of the terminal branchesofbrachial artery, arising in cubital fossa. In middle third of forearm it accompanies the superficial branch of radial nerve. At the level of radial styloid process, it passes backward to enter into anatomical snuffbox. Radial artery is the only content of anatomical snuff box. Leaving the anatomical snuff box it passes between two heads of first dorsal interosseous muscle and then between two heads of adductor pollicis. After that is continues as deep palmar arch, which is completed by deep branch of ulnar artery.
Branches of radial Artery are:-
1. In forearm
2. In Dorsum of hand
3. In the Palm
a. Radial recurrent:-Anastomoses with the radial collateral branch of prof and a brachii.
b. Palmar carpal branch :- Forms palmar carpal arterial arch with
i) Palmar carpal branch of ulnar artery.
ii) Branch from anterior interosseous artery.
iii) Recurrent branch of deep palmar arch.
c. Superficial palmar branch: - It terminates by completing the superficial palmar arch, which 1S mainly
a. Dorsal carpal branch :- Forms dorsal carpal arterial arch with
i) Dorsal branch of ulnar artery.
ii) Branch from anterior interosseous artery.
iii) Branch from posterior interosseous artery.
b. First dorsal metacarpal branch: - Supplies dorsum of thumb and lateral margin of index finger.
a. Princepspollicisartery: - Supplies palmar aspect ofthumb.
b. Radialisindicisartery: - Supplies palmar aspect of radial margin of index finger.
It is the larger terminal branch of brachial artery, arising in the cubital fossa. In the distal two-third of forearm, it is accompanied by ulnar nerve. It enters the palm by passing superficial to flexor retinaculumand divides into superficial and deep terminal branches, just distal to pisiform. Its branches are -
- In cubitalfossa
- Anterior ulnar recurrent: - Anastomoses with inferior ulnar collateral in from of medial epicondyle.
- Posterior ulnar recurrent: - Anastomoses with superior ulnar collateral behind medial epicondyle.
- Common interosseous :- Divides into
- Anterior interosseous.
- â€‹Posterior interosseous.
- In forearm
- Palmar carpal branch
- Dorsal carpal branch
- In palm: - These are terminal branches.
- Deep branch: - Completes the deep palmar arch on medial side by joining the terminal part of radial artery.
- Superficial branch: - Forms the major part of superficial palmar arch.
Deep palmar arch
- It lies across the base of metacarpal bones. It is formed mainly by radial artery and completed by deep branch of ulnar artery. Its branches are :-
- Three palmar metacarpal arteries on the II, III and IV palmar interossei muscles join the digital branches of superficial palmar arch.
- Three perforating arteries: - Anastomose with dorsal metacarpal arteries.
- Recurrent branches: - Supply carpal bones and join palmar carpal arch.
- The deep palmar arch lies deep to the oblique head of adductor pollicis, long flexor tendon and lumbricalmusclesand passes across the base of metacarpal and interossei.
Superficial palmar arch
- This arch lies just deep to palmar aponeurosis, in front of long flexor tendons, and lumbricals. The arch is mainly formed by superficial terminal branch of ulnar arteryand is completed on lateral side by one of the following artery.
- Superficial palmar branch of radial artery.
- Princeps pollicis artery.
- Radialis indicis artery.
- Arteria Nervimediana which accompanies the median nerve.
- Branches of the arch are four palmar digital arteries arise from the convexity of the arch. The most medial digital branch passes along the ulnar side of the little finger. The remaining three branches form the common palmar digital arteries which proceed distally to the web between the fingers, where each joins with the palmar metacarpal artery of the deep palmar arch and then divides into two proper palmar digital arteries to supply the adjacent fingers.
- Therefore, the superficial palmar arch does not supply the radial side of index finger and both sides of the thumb.
Important Spaces And Structures
Space of arm
Space of arm
Space of arm
Superior: Teres minor
Inferior: Teres major
Lateral: Long bead oftriceps
Superior: Teres minor
Medial: Teres major
Lateral: Shaft of humerus
Superior: Teres minor subscapularis, joint capsule
Medial: Long bead of triceps
Lateral: Surgical neck of humerus
Circumflex scapular artery
Profunda brachii vessels
Posterior circumflex humeral vessels
Triangles of Auscultation
- It is a small triangular space on the back, near inferior angle of scapula, where the relatively thin musculature allows for respiratory sounds to be heard more clearly with a stethoscope. The sounds of swallowed fluids can besometimes heard in esophageal obstruction as cardiac orifice of stomach lies deep to this triangle. It is formed by -
- Medially:- Lateral border oftrapezius
- Laterally :- Medial border of scapula
- Inferiorly :- Upper border oflatissimusdorsi
- Floor is formed by: - 6th and 7th rib with intercostal space between them, rhomboideus major.
- Apex of lower lobe of both lungs lies beneath this triangle.
Flexor retinaculum (Transverse carpal ligament)
It is the thickened part of deep fascia of carpal region, bridging over the palmar concavity of carpal bones and converting it into carpal tunnel. It is medially attached to pisiform and hook of hamate. Laterally it is attached to tubercle of scaphoid and trapezium. Laterally, retinaculum spits into two parts, which divides the carpal tunnel into two compartments: (i) Smaller lateral and a larger medial (carpal tunnel proper).
Structures passing deep to flexor retinaculum (through carpal tunnel):
- Lateral compartment: Flexor carpi radialis tendon with its synovial sheath lodged in the groove on the palmar surface of trapezium.
- Medial compartment: (carpal tunnel proper).
- Median nerve
- Flexor pollicis longus with its synovial sheath (radial bursa)
- 4 tendons each of flexor digitorum superficialisand profundus enclosed by common flexor synovial sheath (ulnar bursa).
Structures passing superficially to flexor retinaculum:
- Palmaris longus tendon continuous with apex of palmar aponeurosis.
- Palmar cutaneous branch of median nerve.
- Palmar cutaneous branch of ulnar nerve.
- Ulnar nerve.
- Ulnar vessels protected superficially by volar carpal ligament (superficial part of the flexor retinaculum).
- It is the thickened part of deep fascia at the back of wrist.
- Laterally, it is attached to the lower part of the anterior border of the radius; it is medially attached to the triquetraland pisiform bones. Deep to the retinaculum, 9 extensor tendons pass through 6 commpartments. Each compartment has one synovial sheath enveloping the tendons. From lateral to medial, the compartments transmit.
- Abductor pollicislongus, extensor pollicisbrevis (Compartment I).
- Extensor carpi radialis longus and brevis (Compartment II).
- Extensor pollicis longus (Compartment III).
- Extensor digitorurn & extensor indicis, posterior interosseous nerve and anterior interosseous artery (Compartment IV).
- Extensor digiti minimi (Compartment V).
- Extensor carpi ulnaris (Compartment VI).
- Inflammation and nodule formation in the synovial sheath of abductor pollicis longus and extensor pollicis brevis, resulting in pain over radial styloid, is known as De Quervain's tenosynovitis.
Synovial sheaths of flexor tendon
Synovial flexor sheaths include ulnar bursa and radial bursa.
Ulnar bursa (common flexor synovial sheath)
- In the hand, tendons of flexor digitorum superficial and profundus (FDS and FDP) invaginate common synovial sheath, called ulnar bursa. It begins 2.5cm proximal to flexor retinaculum in the distal forearm and envelops the tendons in the carpal tunnel. Extending distally, the ulnar bursa continues to envelop the tendon the little finger to become digital synovial sheath of little finger. But it ends blindly, at the level of the middle of metacarpals, around tendons to index,
- Distal part of ulnar bursa lies in mid palmar space.
- It is the synovial sheath of tendon of flexor pollicis longus which begins 2.5 cm. proximal to the flexor retinaculum.
- Distally in becomes continuous with the digital synovial sheath of thumb. Distal part of the radial bursa in the palm is related to the thenar space.
- Thus infection of little finger affects ulnar bursa and infection of thumb affects radial bursa.