Correct spelling for musculus extensor primi internodii pollicis [Infographic]

MUSCULUS EXTENSOR PRIMI INTERNODII POLLICIS Meaning and Definition

The term "musculus extensor primi internodii pollicis" is a Latin phrase used in anatomy to describe a specific muscle located in the human hand. Breaking down the term, "musculus" translates to "muscle," "extensor" refers to a muscle that causes the extension or straightening of a body part, "primi" means "first," "internodii" signifies an "intermediate phalanx" or the middle bone of the finger or thumb, and "pollicis" pertains to the thumb.

Therefore, the "musculus extensor primi internodii pollicis" is the muscle responsible for extending or straightening the first (or proximal) phalanx of the thumb. Situated in the back of the hand, this muscle is part of the extensor pollicis longus muscle group, which originates from the ulna and radius bones in the forearm before attaching to the thumb.

The function of the "musculus extensor primi internodii pollicis" is integral to thumb extension and plays a crucial role in thumb movement and dexterity. When this muscle contracts, it pulls on the tendons connected to the thumb, causing the first bone of the thumb to straighten or extend. This extension of the thumb is crucial for activities such as grasping objects, pinching, and fine motor tasks requiring thumb opposition. Thus, the "musculus extensor primi internodii pollicis" contributes to the intricate coordination and flexibility of the human hand.
M. Extensor pollicis brevis.

A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.