🩺 Vessels of the Upper Limb - Handwritten Notes

ARTERIAL SUPPLY - Overview

Subclavian A. → Axillary A. → Brachial A. → Radial A. + Ulnar A. → Palmar Arches

1. SUBCLAVIAN ARTERY

• Right side: from the brachiocephalic trunk
• Left side: directly from the aortic arch

• Part I - medial to anterior scalene
• Part II - posterior to anterior scalene
• Part III - lateral to anterior scalene → becomes axillary A. at the inferior border of rib I

2. AXILLARY ARTERY

• Superior thoracic artery → 1st & 2nd intercostal spaces, pectorals, serratus anterior (superior)

• Thoracoacromial artery → divides into pectoral, acromial, deltoid, clavicular branches; forms acromial anastomosis near acromion
• Lateral thoracic artery → serratus anterior, lateral chest wall; larger in women (supplies mammary glands)

• Subscapular artery (largest axillary branch)
  • → Circumflex scapular a.: passes through triangular space (between teres major/minor), reaches infraspinous fossa; anastomoses with suprascapular a.
  • → Thoracodorsal a.: accompanies thoracodorsal nerve to latissimus dorsi; also supplies teres major, subscapularis, serratus anterior
• Anterior circumflex humeral artery → passes anteriorly around surgical neck of humerus
• Posterior circumflex humeral artery (larger) → passes posteriorly through quadrangular space (lateral space between teres major/minor); supplies shoulder joint and surrounding muscles

Scapular anastomosis: suprascapular a. + circumflex scapular a. + posterior scapular a. form a rich network. Even if axillary A. is ligated proximal to the subscapular branch, the arm rarely becomes ischemic.

Fig. 2.25 - Axillary and brachial arteries (Color Atlas of Human Anatomy)

3. BRACHIAL ARTERY

Cubital anastomosis: Arterial plexus around the elbow formed by descending branches (profunda brachii, brachial artery) and ascending recurrent branches (radial recurrent, ulnar recurrent, interosseous recurrent). Permits safe ligation of brachial A. distal to the profunda brachii origin. Also permits radial A. harvest as a graft (collateral flow via ulnar A. recurrents).

4. RADIAL ARTERY

• Proximally: between pronator teres and brachioradialis
• Distally: between tendons of brachioradialis and flexor carpi radialis → radial pulse palpable here
• Turns posteriorly → passes between 1st and 2nd metacarpal heads → enters palm of hand (deep)

• Radial recurrent a. → ascends to cubital anastomosis
• Superficial palmar branch → joins ulnar A. to complete superficial palmar arch
• Palmar carpal branch → palmar carpal arch (wrist plexus)
• Posterior carpal branch → posterior carpal arch
• Princeps pollicis a. → thumb (flexor surface)
• Radialis indicis a. → radial side of index finger (may arise from princeps pollicis)
• Deep palmar arch → main terminal branch; lies on metacarpal bases deep to long flexor tendons; anastomoses with deep palmar branch of ulnar A.

5. ULNAR ARTERY

• Initially runs deep to pronator teres
• Then accompanies flexor carpi ulnaris
• Enters hand lateral to pisiform

• Ulnar recurrent a. (anterior + posterior) → cubital anastomosis
• Common interosseous a. → divides into:
  • Anterior interosseous a. → runs on interosseous membrane (anterior surface)
  • Posterior interosseous a. → pierces interosseous membrane (posterior surface); gives recurrent interosseous a. to cubital anastomosis
• Palmar carpal branch → palmar carpal arch
• Posterior carpal branch → posterior carpal arch
• Deep palmar branch → deep palmar arch
• Superficial palmar arch → main terminal branch (see below)

Fig. 2.26 - Radial and ulnar arteries, palmar arches (Color Atlas of Human Anatomy)

6. VASCULAR ARCHES OF THE HAND

Superficial Palmar Arch

• Formed by: Terminal branch of ulnar A. + superficial palmar branch of radial A.
• Mainly fed by: Ulnar artery
• Lies between: Palmar aponeurosis and long flexor tendons
• Gives: 3 common palmar digital arteries → each divides into 2 proper palmar digital arteries (supplies adjacent sides of fingers)

Deep Palmar Arch

• Formed by: Terminal branch of radial A. + deep palmar branch of ulnar A.
• Mainly fed by: Radial artery
• Lies on: Bases of metacarpals, beneath long flexor tendons
• Gives: 3-4 palmar metacarpal arteries → interdigital spaces; also perforating branches to dorsum

Posterior Carpal Arch (Dorsal)

• Formed by posterior carpal branches of radial + ulnar arteries
• Gives 4 posterior (dorsal) metacarpal arteries → 2 posterior digital arteries each

Allen's Test checks the patency of the superficial palmar arch and is done before radial A. cannulation or harvest.

VEINS OF THE UPPER LIMB

Deep Veins

Clinical note: The subclavian vein (actually first part of axillary vein) is used for central venous access. Infraclavicular needle entry aimed superomedially. Risk: pneumothorax, brachial plexus injury, subclavian artery puncture.

Superficial Veins

• Arises from the superficial posterior (dorsal) venous network of the hand
• Passes to the flexor (anterior) side of the wrist
• Ascends on the radial side of the forearm
• Travels in the lateral bicipital groove of the arm
• Pierces the clavipectoral fascia in the deltopectoral (clavipectoral) triangle
• Opens into the axillary vein

• Arises above the distal ulna
• Ascends on the ulnar side of the forearm
• Pierces the muscle fascia at the middle of the arm
• Enters the medial bicipital groove
• Opens into one of the brachial veins

• Connects cephalic and basilic veins across the cubital fossa
• Passes from inferolateral to superomedial
• Also communicates with deep veins
• Clinically important: Most commonly used site for venipuncture and IV cannulation

Clinical note: Subcutaneous veins of the hand and elbow are used for IV access, blood sampling, and long-term catheterization (Hickman lines, PICC lines).

Fig. 2.34 - Veins of the upper limb: A. Deep veins, B. Dorsal veins of hand, C. Superficial veins & palmar veins (Color Atlas of Human Anatomy)

CLINICAL CORRELATIONS

QUICK SUMMARY FLOWCHART

Aorta (left) / Brachiocephalic trunk (right)
         ↓
  SUBCLAVIAN ARTERY
  Branches: Vertebral, Internal thoracic, Thyrocervical trunk,
            Costocervical trunk, Posterior scapular
         ↓ (at inferior border of rib I)
  AXILLARY ARTERY (3 parts, pec minor divides)
  Part 1: Superior thoracic
  Part 2: Thoracoacromial, Lateral thoracic
  Part 3: Subscapular, Ant. + Post. circumflex humeral
         ↓ (at inferior border of pec major)
  BRACHIAL ARTERY
  Branches: Profunda brachii, Sup. + Inf. ulnar collateral
         ↓ (at radial neck, cubital fossa)
         ├── RADIAL ARTERY ──────────────────────────┐
         │   Branches: Radial recurrent,              │
         │   Superficial palmar branch, Deep palmar arch│
         │                                            │
         └── ULNAR ARTERY ──────────────────────────┤
             Branches: Ulnar recurrent,              │
             Common interosseous, Superficial palmar arch
                                                     │
                    ┌────────────────────────────────┘
                    ↓
        HAND: Deep Palmar Arch (mainly radial)
              Superficial Palmar Arch (mainly ulnar)
              Posterior Carpal Arch
              Palmar + Dorsal digital arteries

Diagram 1 - Axillary & Brachial Arteries (Fig. 2.25)

Label Key:

Note: Labels 13-20 together form the cubital anastomosis - the arterial plexus encircling the elbow joint.

Diagram 2 - Radial & Ulnar Arteries, Palmar Arches (Fig. 2.26)

Panel A - Arteries of Forearm & Palm (Anterior view):

Panel B - Arteries of Dorsum of Hand:

Panel C - Cross-section through Finger:

• Shows paired proper palmar digital arteries (yellow/red dots - ventral)
• Shows paired proper dorsal digital arteries (blue dots - dorsal)
• Central white = phalanx bone

Diagram 3 - Veins of the Upper Limb (Fig. 2.34)

Panel A - Deep Veins of Upper Limb:

Panel B - Dorsal (Posterior) Venous Network of Hand:

Panel C - Superficial Veins (Anterior view):

Summary Diagram - Relationship of the Three Superficial Veins

Cephalic V.                    Basilic V.
(radial/lateral side)          (ulnar/medial side)
      |                               |
      |         Median Cubital V.     |
      |___________(cubital fossa)_____|
      |
Ascends in lateral              Ascends in medial
bicipital groove                bicipital groove
      |                               |
Pierces clavipectoral           Pierces deep fascia
fascia (deltopectoral           at mid-arm level
triangle)                              |
      |                               |
Drains into                     Drains into
AXILLARY VEIN                   BRACHIAL VEIN

Venipuncture tip: The median cubital vein is preferred for blood draws because it is large, superficial, relatively fixed (supported by bicipital aponeurosis), and separated from the brachial artery and median nerve by the bicipital aponeurosis - reducing the risk of accidental arterial puncture.