Radial Artery

Ans. C: Radial artery

The boundaries of anatomical snuff box:

• The medial border of the snuffbox is the tendon of the extensor pollicis longus.
• The lateral border is a pair of parallel and intimate tendons, of the extensor pollicis brevis and the abductor pollicis longus. (Accordingly, the anatomical snuffbox is most visible, having a more pronounced concavity, during thumb extension.)
• The proximal border is formed b^y the styloid process of the radius
• The distal border is formed by the approximate apex of the schematic snuffbox isosceles triangle.
• The floor of the snuffbox varies depending on the position of the wrist, but both the trapezium and primarily the scaphoid can be palpated

Deep to the tendons which form the borders of the anatomical snuff box lies the radial artery, which passes through the anatomical snuffbox on its course from the normal radial pulse detecting area, to the proximal space in between the first and second metacarpals to contribute to the superficial and deep palmar arches.

Ans. is ‘d’ i.e., ECU 

Anatomical Snuffbox

• Triangular depression on the dorsal and radial aspect of the hand become visible when thumb is fully extended. Boundaries
• Medial/Posterior → Tendon of the extensor pollicis longus.
• Lateral/Anterior  → Tendon of the extensor pollicis brevis and abductor pollicis longus.
• Roof  Skin and  → fascia with beginning of cephalic vein and crossed by superficial branch of the radial nerve.
• Floor   → Styloid process of radius, trapezium, scaphoid and base of 1st metacarpal.
• Contents → The radial artery.

Ans. is ‘a’ i.e., Extensor pollicis longus