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 (2025) 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 Rate This Article