Topic Overview

Viva Voce – Cutaneous Nerves, Superficial Veins & Lymphatic Drainage

Cutaneous Nerves & Dermatomes

Q1. What is a dermatome?
→ Area of skin supplied by sensory fibers of 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 the medial forearm?
→ T1.

Q6. Which dermatome supplies the shoulder tip?
→ C4.

Q7. Which nerve supplies the regimental badge area?
→ Axillary nerve.

Q8. Which nerve supplies dorsum of lateral 3½ proximal phalanges?
→ Radial nerve.

Q9. Which nerve supplies palmar aspect of lateral 3½ fingers?
→ Median nerve.

Q10. Which nerve supplies palmar and dorsal aspect of medial 1½ fingers?
→ Ulnar nerve.

Q11. How do you test C6 dermatome clinically?
→ Sensation over thumb.

Q12. How do you test C7 dermatome clinically?
→ Sensation over middle finger.

Q13. How do you test C8 dermatome clinically?
→ Sensation over little finger.

Q14. Which nerve supplies lateral forearm skin?
→ Musculocutaneous nerve (lateral cutaneous nerve of forearm).

Q15. Which nerve supplies medial forearm skin?
→ Medial cutaneous nerve of forearm.

Superficial Veins

Q16. Which vein connects cephalic and basilic veins at cubital fossa?
→ Median cubital vein.

Q17. Which vein is most commonly used for venipuncture?
→ Median cubital vein.

Q18. Why is median cubital vein preferred for venipuncture?
→ Large, superficial, fixed by perforators, away from major nerves and arteries.

Q19. Which vein is used for cardiac catheterization?
→ Cephalic vein (deltopectoral groove → axillary → subclavian → heart).

Q20. Which vein is preferred for long-term IV cannulation?
→ Basilic vein.

Q21. Which vein runs in the deltopectoral groove?
→ Cephalic vein.

Q22. From which vein do cephalic and basilic veins originate?
→ Dorsal venous arch of hand.

Q23. Which vein pierces clavipectoral fascia to drain into axillary vein?
→ Cephalic vein.

Q24. Which superficial vein is commonly used in creating AV fistula for dialysis?
→ Cephalic vein.

Lymphatic Drainage

Q25. Where are supratrochlear lymph nodes located?
→ Just above the medial epicondyle of humerus.

Q26. Which areas do supratrochlear nodes drain?
→ Medial fingers, medial hand, medial forearm.

Q27. Which lymph nodes are the first involved in infections of hand?
→ Supratrochlear nodes.

Q28. Which lymph nodes receive lymphatics accompanying basilic vein?
→ Supratrochlear → humeral axillary nodes.

Q29. Which lymph nodes receive lymphatics accompanying cephalic vein?
→ Apical axillary nodes.

Q30. Which lymph nodes receive deep lymphatics of upper limb?
→ Humeral (lateral) axillary nodes.

Q31. Name the groups of axillary lymph nodes.
→ Pectoral, subscapular, humeral, central, apical.

Q32. Which group of axillary nodes is first involved in carcinoma breast?
→ Pectoral group.

Q33. Which condition causes enlargement of axillary nodes with cold abscess?
→ Tuberculosis.

Q34. Why does lymphedema occur after mastectomy with axillary clearance?
→ Removal of axillary lymph nodes interrupts lymphatic drainage.

Q35. Which nerve carries referred cardiac pain to medial arm?
→ Intercostobrachial nerve (T2).