Abductor pollicis longus muscle Abductor pollicis longus muscle In human anatomy, the abductor pollicis longus (APL) is one of the extrinsic muscles of the hand. As the name implies, its major function is to abduct the thumb at the wrist. Its tendon forms the anterior border of the anatomical snuffbox. The abductor pollicis longus lies immediately below the supinator and is sometimes united with it. It arises from the lateral part of the dorsal surface of the body of the ulna below the insertion of the anconeus, from the interosseous membrane, and from the middle third of the dorsal surface of the body of
Anatomical plane a person jumped directly up and then down, their body would be moving through the transverse plane in the coronal and sagittal planes. A "longitudinal plane" is any plane perpendicular to the transverse plane. The coronal plane and the sagittal plane are examples of longitudinal planes. Sometimes the orientation of certain planes needs to be distinguished, for instance in medical imaging techniques such as sonography, CT scans, MRI scans, or PET scans. One imagines a human in the anatomical position, and an X-Y-Z coordinate system with the y-axis going from front to back, the x-axis going from left to right,