The arterial trunk of the thumb-index digital collaterals.

This is a study of the origin of the palmar collateral arteries of the thumb and radial side of the index finger. The different patterns of the main trunk, the first palmar interosseous artery, in the commissure are discussed, together with the relations of its branches with those of the superficial palmar arch and its relations with the accessory fasciculi of the adductor pollicis and first dorsal interosseous muscles.