abductor pollicis muscle

A muscle (abductor pollicis muscle) that performs abduction, moving a body part away from the midline or central axis.

Type Muscle
Parent Structure forelimb muscle

Sub-structures

abductor pollicis longus Organ

Frequently Asked Questions

What is the abductor pollicis muscle?
The abductor pollicis muscle is any muscle that performs abduction of the thumb (pollicis), moving it away from the midline or central axis of the hand. This category includes both the abductor pollicis brevis (short, intrinsic) and the abductor pollicis longus (long, extrinsic).
Where is the abductor pollicis muscle located?
The abductor pollicis muscles are located at the thumb side of the hand and wrist. The brevis forms part of the thenar eminence in the palm, while the longus lies in the posterior forearm with its tendon crossing over the wrist to reach the base of the first metacarpal.
What is the function of the abductor pollicis muscle?
The abductor pollicis muscles move the thumb away from the index finger and the palm, enabling the full range of thumb positioning necessary for pinch, grip, and opposition. This range of motion is fundamental to human manual dexterity.
What conditions can affect the abductor pollicis muscle?
Median nerve injury affects the abductor pollicis brevis, while radial nerve injury affects the abductor pollicis longus, each producing characteristic functional limitations. De Quervain's tenosynovitis involves the longus tendon sheath, and carpal tunnel syndrome affects the brevis.
How do the short and long abductor pollicis muscles differ?
The short abductor (brevis) is an intrinsic hand muscle innervated by the median nerve and produces palmar abduction of the thumb at the metacarpophalangeal joint, while the long abductor (longus) is an extrinsic forearm muscle innervated by the radial nerve and abducts the first metacarpal.

Related Structures

1st arch mandibular component ventral mandibular arch 1st arch mandibular ectoderm ectoderm of mandibular component 1st arch mandibular mesenchyme mandibular component mesenchyme 1st arch mandibular mesenchyme from head mesenchyme 1st arch mandibular mesenchyme from neural crest 1st arch maxillary component 1st arch maxillary ectoderm ectoderm of maxillary component 1st arch maxillary-mandibular cleft 1st arch maxillary-mandibular groove ectoderm

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Educational Disclaimer

This content is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider for medical decisions.

Data sources: Terminologia Anatomica, Foundational Model of Anatomy, Wikidata.