Final answer:
The flexor digitorum superficialis and flexor digitorum profundus muscles are responsible for flexing the digits and the wrist, whereas the extensor digitorum muscle extends them.
Step-by-step explanation:
The flexor digitorum superficialis and flexor digitorum profundus flex the digits and the wrist (hand). These muscles are particularly important for the fine motor actions of the hands, such as gripping. The flexor digitorum superficialis flexes the mid-joints of the fingers, while the flexor digitorum profundus muscle flexes the distal joints and also helps in flexing the wrist. Besides these, other muscles like the flexor carpi ulnaris and flexor carpi radialis have specific roles in the movement of the hand; the former flexes and adducts the hand at the wrist, while the latter flexes and abducts the hand. In contrast, the extensor digitorum is an extensor muscle that increases the angle at the joint, thereby extending the fingers and the hand at the wrist.