Flexor pollicis longus muscle

The video tutorial discusses the flexor pollicis longus muscle, one of the three deep flexors of the forearm. It covers the muscle's location, origin, insertion, nerve supply, and functions. The flexor pollicis longus originates from the anterior surface of the radius and sometimes the medial epicondyle of the humerus. Its tendon runs through the carpal tunnel and inserts at the distal phalanx of the thumb. The muscle is innervated by the median nerve, specifically the anterior interosseous nerve. It is responsible for thumb flexion at the MCP and DIP joints, opposition at the saddle joint, and can flex and abduct the wrist joint when the thumb is fixed.

Which of the following muscles is NOT one of the three deep flexors of the forearm?

• Pronator quadratus

• Flexor digitorum profundus

• Flexor carpi radialis

• Flexor pollicis longus

Where does the flexor pollicis longus muscle originate?

• Palmar side of the distal phalanx

• Posterior surface of the ulna

• Anterior surface of the radius

• Lateral epicondyle of the humerus

Which nerve supplies the flexor pollicis longus muscle?

• Radial nerve

• Ulnar nerve

• Median nerve

• Musculocutaneous nerve

What is the primary function of the flexor pollicis longus muscle?

• Extension of the thumb

• Flexion of the thumb

• Adduction of the thumb

• Abduction of the thumb

In addition to thumb flexion, what other movement does the flexor pollicis longus assist with when the thumb is fixed?

• Extension of the wrist

• Supination of the forearm

• Abduction of the wrist

• Pronation of the forearm