Palmar Interossei (Hand) - Podcast Version 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x The palmar interossei are intrinsic muscles of the hand. There are three palmar interossei muscles (although some texts describe a fourth muscle at the base of the proximal phalanx of the thumb). Attachments: Each interossei originates from a medial or lateral surface of a metacarpal, and attaches into the extensor hood and proximal phalanx of same finger. Actions: Adduction of the digits. Assists in flexion at the metacarpophalangeal joints and extension at the interphalangeal joints. Innervation: Ulnar nerve. Blood Supply: Palmar metacarpal arteries By TeachMeSeries Ltd (2026) Fig 1The dorsal and palmar interossei of the hand. 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, demonstrating the palmar interossei. The dorsal interossei are also partially visible. Prosection of the deeper structures of the hand, demonstrating the palmar interossei. The dorsal interossei are also partially visible. 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 are the palmar interossei muscles? The palmar interossei are intrinsic muscles located in the hand, primarily responsible for the adduction of the fingers. There are typically three palmar interossei muscles, with some sources noting a possible fourth muscle associated with the thumb. What are the attachments of the palmar interossei? Each palmar interosseus muscle originates from either the medial or lateral surface of a metacarpal and attaches to the extensor hood and proximal phalanx of the corresponding finger. This arrangement allows for effective movement and control of the digits. What actions do the palmar interossei perform? The palmar interossei facilitate the adduction of the digits and assist in flexing the metacarpophalangeal joints while aiding extension at the interphalangeal joints. These actions are crucial for fine motor skills and grip. Which nerve innervates the palmar interossei muscles? The palmar interossei are innervated by the ulnar nerve. This nerve supply is essential for the proper functioning of these muscles during hand movements. What is the blood supply to the palmar interossei? The palmar interossei receive their blood supply from the palmar metacarpal arteries. This vascularisation supports their function and health within the hand. Rate This Article