Muscle
Flexor pollicis brevis
Thenar - flexes the thumb
High-yield
Thenar; superficial head median (recurrent branch), deep head often ulnar - a hand muscle with dual supply.
Overview
A thenar muscle that flexes the thumb; usually median but its deep head may be ulnar-innervated.
Reference facts
- Origin
- Flexor retinaculum and trapezium (superficial head); trapezoid and capitate (deep head)
- Insertion
- Lateral base of the proximal phalanx of the thumb
- Action
- Flexes the thumb at the carpometacarpal and MCP joints
- Innervation
- Recurrent branch of the median nerve (superficial head); deep branch of the ulnar nerve (deep head)
- Blood supply
- Superficial palmar arch
Frequently asked questions
What does the flexor pollicis brevis do?
The flexor pollicis brevis flexes the thumb at the carpometacarpal and MCP joints.
What nerve innervates the flexor pollicis brevis?
The flexor pollicis brevis is innervated by the recurrent branch of the median nerve (superficial head); deep branch of the ulnar nerve (deep head).
Where does the flexor pollicis brevis attach?
The flexor pollicis brevis originates from the flexor retinaculum and trapezium (superficial head); trapezoid and capitate (deep head) and inserts on the lateral base of the proximal phalanx of the thumb.
What is the blood supply of the flexor pollicis brevis?
The flexor pollicis brevis is supplied by the superficial palmar arch.