Final answer:
The 'extensor digitorum brevis' is a muscle that extends the toes, and its name is derived from its muscle function (extensor), the digits it affects (digitorum), and its relative size (brevis).
Step-by-step explanation:
The name of the extensor digitorum brevis muscle is derived from its function and location. This muscle is part of the dorsal group region along with other muscles like the dorsal interossei, and it plays a role in extending the toes, specifically acting at the metatarsophalangeal and interphalangeal joints. The term 'extensor' indicates that it is a muscle which increases the angle at a joint, and 'digitorum' relates to the digits (fingers or toes). The 'brevis' indicates that it is a shorter muscle in comparison to a 'longus' counterpart, which in this case would be the extensor digitorum longus, a muscle that extends along the leg and foot. These muscles work together with others to provide movement and stability in the human body. For example, extensor muscles like the extensor carpi radialis brevis function to extend and abduct the hand at the wrist, while the extensor digitorum extends the fingers and the hand at the wrist.