Topic Overview

Frequently Asked Questions – Cutaneous Nerves, Superficial Veins & Lymphatic Drainage

Cutaneous Nerves

Q1. What is a dermatome?
→ Area of skin supplied by a single spinal nerve root.

Q2. Which dermatome supplies the thumb?
→ C6.

Q3. Which dermatome supplies the middle finger?
→ C7.

Q4. Which dermatome supplies the little finger?
→ C8.

Q5. Which dermatome supplies medial forearm and arm?
→ T1.

Q6. Which nerve supplies the regimental badge area?
→ Axillary nerve.

Q7. Which nerve supplies dorsum of lateral 3½ proximal phalanges?
→ Radial nerve.

Q8. Which nerve supplies palmar aspect of lateral 3½ digits?
→ Median nerve.

Q9. Which nerve supplies palmar and dorsal surfaces of medial 1½ digits?
→ Ulnar nerve.

Q10. Which nerve supplies posterior forearm skin?
→ Posterior cutaneous nerve of forearm (radial nerve).

Superficial Veins

Q11. From where do superficial veins of upper limb arise?
→ Dorsal venous arch of hand.

Q12. Which vein runs on lateral side of arm and forearm?
→ Cephalic vein.

Q13. Which vein runs on medial side of arm and forearm?
→ Basilic vein.

Q14. Which vein connects cephalic and basilic veins in cubital fossa?
→ Median cubital vein.

Q15. Which vein is most commonly used for venipuncture?
→ Median cubital vein.

Q16. Which vein is used for cardiac catheterization?
→ Cephalic vein (to reach right atrium).

Q17. Which vein is preferred for long-term IV cannulation?
→ Basilic vein.

Lymphatic Drainage

Q18. Which superficial lymph nodes are located above medial epicondyle?
→ Supratrochlear (epitrochlear) nodes.

Q19. Which areas drain into supratrochlear nodes?
→ Medial fingers, medial hand, medial forearm.

Q20. Which lymph nodes drain along basilic vein?
→ Supratrochlear → humeral axillary nodes.

Q21. Which lymph nodes drain along cephalic vein?
→ Apical axillary nodes.

Q22. Which lymph nodes receive deep lymphatics of upper limb?
→ Humeral axillary nodes.

Q23. Which lymph nodes are first involved in carcinoma breast?
→ Pectoral (anterior) group of axillary nodes.

Q24. Final drainage of lymphatics of upper limb is into?
→ Subclavian lymph trunk → thoracic duct (left) / right lymphatic duct (right).

Q25. Which condition causes enlargement of supratrochlear nodes?
→ Infections of hand/forearm.

Q26. Why does lymphedema occur after mastectomy?
→ Removal of axillary nodes interrupts lymphatic drainage of upper limb.

Q27. Which nerve carries referred cardiac pain to medial arm?
→ Intercostobrachial nerve (T2).