Final answer:
The flexor carpi radialis muscle attaches at the base of the second and third metacarpal bones, with a stronger attachment on the second metacarpal. It passes through the carpal tunnel and is sheathed by the flexor retinaculum.
Step-by-step explanation:
The flexor carpi radialis is a muscle of the anterior forearm that acts to flex and abduct the hand at the wrist joint.
This muscle has its origin at the medial epicondyle of the humerus as part of the common flexor tendon.
It then travels down the forearm and inserts onto the base of the second and third metacarpal bones, more prominently on the second metacarpal bone, allowing it to exert force when flexing and radial deviating the wrist.
The tendon of this muscle goes through the carpal tunnel in the wrist, where it is sheathed by the flexor retinaculum.