Extensor Pollicis Longus : Let's break it down!
Extensor: this muscle probably extends something!
Pollicis: referring to the Thumb
Longus: usually indicates there is a shorter version of this muscle (next week ;)
This long thumb muscle closely resembles last weeks Abductor Pollicis Longus , with it's muscle belly starting just above the wrist on the back of the forearm - only this guy has a longer skinny tendon that reaches to the tip of the thumb! This muscle lives underneath the wrist extensor muscles
Official Attachment Points:
Origin: Posterior surface of the ulna and interosseus membrane
Insertion: Distal Phalange of the thumb
Break it down:
Ulna: the forearm bone on the pinky side! (on the other end, the ulna turns into your elbow!)
Interosseous membrane = is a connective tissue between the radius and ulna
Distal phalange of the thumb: whereas the fingers have proximal, middle, and distal phalanges (remember this post?) the thumb has just two : proximal and distal
Muscle Action:
Extends the thumb at the interphalangeal joint
Just like last week, extension of the thumb is basically a thumbs up!
Thumbs up for Muscle Monday! Next week:
The shorter version of this muscle: Extensor Pollicis BREVIS
The shorter version of this muscle: Extensor Pollicis BREVIS
