\Seg*men"tal\, a.
1. Relating to, or being, a segment.
2. (Anat. & Zo["o]l.)
   (a) Of or pertaining to the segments of animals; as, a
       segmental duct; segmental papill[ae].
   (b) Of or pertaining to the segmental organs.
{Segmental duct} (Anat.), the primitive duct of the embryonic
   excretory organs which gives rise to the Wolffian duct and
   ureter; the pronephric duct.
{Segmental organs}.
   (a) (Anat.) The embryonic excretory organs of vertebrates,
       consisting primarily of the segmental tubes and
       segmental ducts.
   (b) (Zo["o]l.) The tubular excretory organs, a pair of
       which often occur in each of several segments in
       annelids. They serve as renal organs, and often, also,
       as oviducts and sperm ducts. See Illust. under
       {Sipunculacea}.
{Segmental tubes} (Anat.), the tubes which primarily open
   into the segmental duct, some of which become the urinary
   tubules of the adult.