The human thumb also has other muscles in the thenar group (opponens and abductor brevis muscle), moving the thumb in opposition, making grasping possible.
Both involve a less developed first metacarpal and a nearly absent thenar musculature.
The thumb has one long flexor and a short flexor in the thenar muscle group.
They drain into a venous plexus which is situated over the thenar and hypothenar eminences and across the front of the wrist.
If the median nerve is damaged, the ability to abduct and oppose the thumb may be lost due to paralysis of the thenar muscles.
It is also occasionally referred to as the thenar branch, or the thenar muscular branch, of the median nerve.
It also supplies the muscles of the thenar eminence by a recurrent thenar branch.
The palm consist of two elongated central pads, a hypothenar pad and a thenar pad.