Enhance your knowledge with our comprehensive guide and curated study materials.
Q1. What is the extent of the arm?
→ From shoulder joint to elbow joint.
Q2. What divides the arm into compartments?
→ Medial and lateral intermuscular septa derived from deep fascia.
Q3. Name the compartments and their nerve supply.
→
Anterior (flexor) → Musculocutaneous nerve.
Posterior (extensor) → Radial nerve.
Q4. What are the palpable bony landmarks of the arm?
→ Acromion, greater and lesser tubercles, medial and lateral epicondyles, and olecranon.
Q5. What is the significance of the line joining the epicondyles and olecranon?
→ In extension → all three lie in a straight line; in flexion → form a triangle → important for diagnosing dislocations and fractures.
Q6. Name the muscles of the anterior compartment.
→ Biceps brachii, Coracobrachialis, Brachialis.
Q7. Which muscle is called the “workhorse” of elbow flexion?
→ Brachialis (acts in all positions of pronation and supination).
Q8. What is the origin of the short and long heads of biceps brachii?
→
Short head → Coracoid process of scapula.
Long head → Supraglenoid tubercle of scapula.
Q9. What is the insertion of biceps brachii?
→ Radial tuberosity and bicipital aponeurosis.
Q10. What is the function of biceps brachii?
→ Flexes elbow and supinates forearm (especially when flexed).
Q11. Which muscle is pierced by musculocutaneous nerve?
→ Coracobrachialis.
Q12. What is the nerve supply of brachialis?
→ Musculocutaneous nerve (C5–C6) and a small branch from radial nerve.
Q13. What is the chief extensor of the elbow joint?
→ Triceps brachii.
Q14. What is the nerve supply of triceps brachii?
→ Radial nerve (C6–C8).
Q15. Which part of triceps is involved in shoulder adduction?
→ Long head.
Q16. What is the insertion of triceps brachii?
→ Olecranon process of ulna.
Q17. What is the action of anconeus muscle?
→ Assists triceps in elbow extension and stabilizes elbow joint.
Q18. What are the spinal segments tested in biceps and triceps reflexes?
→
Biceps reflex → C5–C6 (musculocutaneous).
Triceps reflex → C7–C8 (radial).
Q19. Which nerve supplies all muscles of anterior compartment?
→ Musculocutaneous nerve.
Q20. What is the root value of musculocutaneous nerve?
→ C5, C6, C7.
Q21. What happens if musculocutaneous nerve is injured?
→ Weak elbow flexion and loss of sensation on lateral forearm.
Q22. What is the root value of median nerve?
→ C5–T1.
Q23. What is the relation of median nerve to brachial artery?
→ Lateral in upper arm, crosses in front, medial in lower arm.
Q24. Does median nerve give any branches in arm?
→ No, it gives no branches in the arm.
Q25. What is the root value of ulnar nerve?
→ C8, T1.
Q26. Where does ulnar nerve pierce the medial intermuscular septum?
→ Midway down the arm → then passes behind medial epicondyle.
Q27. Why is ulnar nerve called the “funny bone”?
→ Because it lies superficial behind medial epicondyle; when struck, causes tingling pain along medial forearm and hand.
Q28. What is the root value of radial nerve?
→ C5–T1.
Q29. Which artery accompanies the radial nerve in spiral groove?
→ Profunda brachii artery.
Q30. What are the cutaneous branches of radial nerve in the arm?
→ Posterior cutaneous nerve of arm, lower lateral cutaneous nerve of arm, posterior cutaneous nerve of forearm.
Q31. What is the motor supply of radial nerve in arm?
→ Triceps brachii and anconeus.
Q32. What is the effect of radial nerve injury in spiral groove?
→ Wrist drop (loss of wrist and finger extension).
Q33. What is the effect of radial nerve injury in axilla?
→ Crutch palsy → loss of elbow, wrist, and finger extension.
Q34. From where does the brachial artery arise?
→ Continuation of axillary artery beyond lower border of teres major.
Q35. Where does the brachial artery terminate?
→ At the level of neck of radius in cubital fossa → divides into radial and ulnar arteries.
Q36. What are the branches of brachial artery?
→ Muscular, Profunda brachii, Nutrient to humerus, Superior & inferior ulnar collaterals, Terminal (radial & ulnar).
Q37. Which is the largest branch of brachial artery?
→ Profunda brachii artery.
Q38. Where can brachial pulse be felt?
→ In cubital fossa, medial to tendon of biceps brachii.
Q39. Which vein connects cephalic and basilic veins?
→ Median cubital vein.
Q40. Why is median cubital vein chosen for venipuncture?
→ It is superficial, fixed by perforators, and separated from artery by bicipital aponeurosis.
Q41. What is the cubital fossa?
→ A triangular depression on anterior aspect of elbow.
Q42. What are its boundaries?
→
Medial → Pronator teres.
Lateral → Brachioradialis.
Base → Line joining epicondyles.
Q43. What forms the roof of the cubital fossa?
→ Skin, superficial fascia, median cubital vein, and bicipital aponeurosis.
Q44. What forms the floor of cubital fossa?
→ Brachialis (medially) and Supinator (laterally).
Q45. What are the contents (from medial to lateral)?
→ Median nerve, Brachial artery, Biceps tendon, Radial nerve.
Q46. What lies superficial to the fossa and may be used for blood sampling?
→ Median cubital vein.
Q47. What is the clinical importance of bicipital aponeurosis?
→ It separates the median cubital vein from the brachial artery, preventing accidental arterial puncture.
Q48. What is tested by biceps jerk?
→ Integrity of musculocutaneous nerve (C5–C6).
Q49. What is tested by triceps jerk?
→ Integrity of radial nerve (C7–C8).
Q50. What happens if the brachial artery is injured in supracondylar fracture?
→ May cause Volkmann’s ischemic contracture due to muscle ischemia.
Q51. What are the signs of Volkmann’s ischemic contracture?
→ Flexion deformity of wrist & fingers, pain on passive extension, and claw-like posture.
Q52. What happens in musculocutaneous nerve injury?
→ Weak flexion at elbow, loss of lateral forearm sensation.
Q53. What are the effects of ulnar nerve injury at elbow?
→ Claw hand, loss of sensation in medial 1½ fingers.
Q54. What is the effect of median nerve injury in the arm?
→ Weak pronation, loss of flexion of thumb and index, ape hand deformity
Get the full PDF version of this chapter.
Continue with Google