In the hand anatomy, Structure G corresponds to which metacarpophalangeal joint in the described set?

• A. Second proximal interphalangeal joint
• B. First carpometacarpal joint
• C. Second distal interphalangeal joint
• D. Second metacarpophalangeal joint

Answer: (D)

This question tests identifying the metacarpophalangeal joint by naming the bones involved. The metacarpophalangeal joints are where each finger’s proximal phalanx meets its corresponding metacarpal. For the index finger, that’s the joint between the second metacarpal and the proximal phalanx. It’s the knuckle at the base of the index finger. The other options refer to different joints: the base of the thumb is the first carpometacarpal joint; the joint between the middle and distal phalanges is the distal interphalangeal joint; and the joint between the proximal and middle phalanges is the proximal interphalangeal joint. So Structure G, located at the base of the index finger where the metacarpal meets the proximal phalanx, is the second metacarpophalangeal joint.