Palmaris Longus
The structure indicated is the palmaris longus muscle of the forearm. The palmaris longus is one of four muscles in the superficial layer of muscles in the anterior compartment of the forearm. The anterior compartment of the forearm consists of three layers of muscles:- Superficial layer
- Intermediate layer
- Deep layer
- Flexor carpi ulnaris
- Palmaris longus
- Flexor carpi radialis
- Pronator teres
Origin: medial epicondyle of humerus
Insertion: distal half of flexor retinaculum and palmar aponeurosis
Action: flexion of wrist. Tightens palmar aponeurosis
Innervation: Median nerve
Learn more about the anatomy of the muscles of the forearm in this tutorial.