Questions: The extensor carpi radialis brevis assists in which of the following actions? A) Moving the little finger across the palm B) Moving the thumb across the palm C) Extending and abducting the wrist. D) Flexing the wrist

The answer is C: Extending and abducting the wrist.

Explanation for each option:

A. Moving the little finger across the palm - This action is primarily performed by the muscles of the hand, such as the opponens digiti minimi, not the extensor carpi radialis brevis.

B. Moving the thumb across the palm - This action is primarily performed by the opponens pollicis and other intrinsic muscles of the thumb, not the extensor carpi radialis brevis.

C. Extending and abducting the wrist - This is the correct action of the extensor carpi radialis brevis. It is a muscle in the forearm that helps extend the wrist and abduct it (move it away from the midline of the body).

D. Flexing the wrist - This action is performed by the flexor muscles of the forearm, such as the flexor carpi radialis and flexor carpi ulnaris, not the extensor carpi radialis brevis.

In summary, the extensor carpi radialis brevis is involved in extending and abducting the wrist.