lactiferous sinus


lac·tif·er·ous si·nus

[TA] a circumscribed spindle-shaped dilation of the lactiferous duct just before it enters the nipple. In nursing mothers, this dilation stores a droplet of milk that is expressed by compression as the infant begins to suckle; this is thought to encourage continual suckling while the let-down reflex ensues. Synonym(s): sinus lactiferi [TA], ampulla lactifera, ampulla of lactiferous duct, ampulla of milk duct, lactiferous ampulla

lac·tif·er·ous si·nus

(lak-tif'ĕr-ŭs sī'nŭs) [TA] A circumscribed spindle-shaped dilation of the lactiferous duct just before it enters the nipple. In nursing mothers this dilation stores a droplet of milk that is expressed by compression as the infant begins to suckle; this is thought to encourage continual suckling while the let-down reflex ensues.

lactiferous sinus

Immediately inside the tip of the nipple, the dilated end of any of the 15-20 lactiferous ducts, which convey milk from the mammary glands during lactation.See also: sinus