Topic Overview

Facts to Remember – Cutaneous Nerves, Superficial Veins & Lymphatic Drainage

Cutaneous Nerves

• All skin of upper limb supplied by branches of brachial plexus, except upper shoulder region (C3–C4 supraclavicular nerves).

• C5 dermatome → lateral arm.

• C6 dermatome → thumb.

• C7 dermatome → middle finger.

• C8 dermatome → little finger.

• T1 dermatome → medial forearm & arm.

• Axillary nerve → skin over regimental badge area.

• Radial nerve → posterior arm, forearm, dorsum of hand (lateral 3½ proximal phalanges).

• Median nerve → palmar surface of lateral 3½ digits.

• Ulnar nerve → palmar & dorsal surfaces of medial 1½ digits.

Superficial Veins

• Originate from dorsal venous arch of hand.

• Cephalic vein → lateral side → drains into axillary vein.

• Basilic vein → medial side → joins brachial veins to form axillary vein.

• Median cubital vein → connects cephalic and basilic at cubital fossa → preferred site for venipuncture.

• Cephalic vein used for cardiac catheterization (into right atrium).

• Basilic vein preferred for long-term IV cannulation.

Lymphatic Drainage

• Superficial lymphatics → follow superficial veins.

  • Along cephalic vein → directly to apical axillary nodes.

  • Along basilic vein → to supratrochlear nodes → humeral axillary nodes.

• Deep lymphatics → follow deep veins → drain into humeral axillary nodes.

• Axillary lymph nodes → five groups (pectoral, subscapular, humeral, central, apical).

• Final drainage → subclavian lymph trunk → thoracic duct (left) / right lymphatic duct (right).

• Supratrochlear nodes enlarge in infections of hand/forearm.

• Axillary nodes are first involved in carcinoma breast (especially pectoral group).

• Lymphedema occurs after axillary clearance (e.g., mastectomy).