Flexor Pollicis Brevis - Podcast Version TeachMeAnatomy 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x The flexor pollicis brevis is a thenar muscle located within the hand. It forms the medial aspect of the thenar eminence and is described as having a superficial and deep part (although the deep component is variable in size). Attachments: Originates from the tubercle of the trapezium and from the associated flexor retinaculum. Attaches to the base of the proximal phalanx of the thumb. Actions: Flexes the metacarpophalangeal joint of the thumb. Innervation: Median nerve (recurrent branch). The deep head is innervated by the deep branch of the ulnar nerve. Blood supply: Superficial palmar arch By TeachMeSeries Ltd (2026) Figure 1Palmar view of the thenar muscles. Pro Feature - 3D Model You've Discovered a Pro Feature Access our 3D Model Library Explore, cut, dissect, annotate and manipulate our 3D models to visualise anatomy in a dynamic, interactive way. Learn More Pro Feature - Dissection Atlas Prosection of the deeper structures of the hand. The deep branch of the ulnar nerve innervates the majority of the muscles of the hand (except the lateral two lumbricals and the thenar eminence). Note the two-headed structure of the adductor pollicis. Prosection of the deeper structures of the hand. The deep branch of the ulnar nerve innervates the majority of the muscles of the hand (except the lateral two lumbricals and the thenar eminence). Note the two-headed structure of the adductor pollicis. You've Discovered a Pro Feature Access our Dissection Image Library Enhance your understanding with high-resolution dissection images showcasing real-life anatomy. Learn More Frequent questions What is the flexor pollicis brevis? The flexor pollicis brevis is a muscle in the hand that is part of the thenar eminence, contributing to thumb movement. It consists of a superficial part and a variable deep component. Where does the flexor pollicis brevis originate? This muscle originates from the tubercle of the trapezium bone and the flexor retinaculum. These attachments provide a stable base for its function in thumb flexion. What is the primary action of the flexor pollicis brevis? The primary action of the flexor pollicis brevis is to flex the metacarpophalangeal joint of the thumb. This movement is essential for grasping and pinching actions. How is the flexor pollicis brevis innervated? The flexor pollicis brevis is primarily innervated by the recurrent branch of the median nerve. Additionally, the deep head receives innervation from the deep branch of the ulnar nerve. What is the blood supply for the flexor pollicis brevis? The blood supply to the flexor pollicis brevis comes from the superficial palmar arch. This vascularisation is crucial for maintaining the muscle's function and health. Rate This Article