Musculus abductor pollicis brevis

The video tutorial explains the abductor pollicis brevis muscle, a key muscle in the thumb. It covers its location, origin from the scaphoideum and trapezium bones, and attachment to the thumb. The muscle is innervated by the median nerve from the brachial plexus. Its primary functions include thumb abduction and flexion at the thumb base joint.

What is the primary origin of the abductor pollicis brevis muscle?

Which nerve innervates the abductor pollicis brevis muscle?

From which segments of the spinal cord do the fibers of the abductor pollicis brevis muscle originate?

Describe the functions of the abductor pollicis brevis muscle.

What is the anatomical significance of the abductor pollicis brevis muscle in relation to the thumb?