Bones of the Hand Quiz

See Phalanges. Option E is correct because every finger has three phalanges, the proximal, middle and distal phalanx, except the thumb, which has only two, a proximal and a distal phalanx, because it has no middle phalanx. Phalanges (the singular is phalanx) are the bones of the digits. Proximal means nearest the wrist and distal means furthest from it, so the proximal phalanx is the one that joins the metacarpal and the distal phalanx is the one at the fingertip. Each phalanx has a base, a shaft and a head. This pattern fixes the joints: a finger has a metacarpophalangeal joint, a proximal interphalangeal joint and a distal interphalangeal joint, whereas the thumb has only one interphalangeal joint after its metacarpophalangeal joint. The same pattern is seen in the foot, where the big toe has two phalanges and the other toes have three. Memory aid: the thumb and big toe are the odd ones out, each with two phalanges while the other digits have three.

• Fingers: each finger has three phalanges, the proximal, middle and distal.
• Thumb: the thumb has only two phalanges, a proximal and a distal, because it has no middle phalanx.
• Foot: the big toe has two phalanges and the other toes have three.

A reverses the real pattern: the thumb has two phalanges, and each finger has three, so the thumb does not have three while the fingers have two. C gets the thumb right but gives each finger only two phalanges, when each finger also has a middle phalanx. D gives the fingers the correct number, but the thumb has only proximal and distal phalanges and lacks a middle phalanx. B undercounts both: the thumb has proximal and distal phalanges, and each finger has proximal, middle and distal phalanges.