EXTENSOR POLLICIS BREVIS MUSCLE Meaning and
Definition
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The extensor pollicis brevis muscle is an anatomical structure located in the forearm and wrist region of the human body. It is a slender, elongated muscle that lies on the dorsal side of the forearm, extending from the posterior part of the ulna bone to the base of the thumb.
Functionally, the extensor pollicis brevis muscle is responsible for the movement and stabilization of the thumb joint. It acts as an extensor, that is, it assists in the straightening and extension of the thumb, specifically at the carpometacarpal and metacarpophalangeal joints. This muscle is particularly important for actions involving opposition, allowing the thumb to move towards and touch the other fingers, as well as for gripping and grasping objects.
In terms of its origin and insertion, the extensor pollicis brevis muscle originates from the lateral part of the middle ulna and the interosseous membrane between the radius and ulna bones. It then runs along the posterior surface of the forearm and passes through the tendons of the extensor muscles to eventually insert into the base of the proximal phalanx bone of the thumb.
Overall, the extensor pollicis brevis muscle plays a crucial role in the intricate coordination of hand movements, allowing for precise thumb actions and enabling various manual tasks.
