Textbook of normal histology: including an account of the development of the tissues and of the organs . lar debris of old epithelialcells, are collected within analbuminous fluid and consti-tute the lactiferous secre-tion. The assumed destruction of the epithelial cells following thedischarge of the oil-globules is improbable, since the cell then simplyenters upon a period of rest and repair, during which its powers ofsecretion are recuperated. In the earliest stage of the activity of themammary gland, when the flow of milk is first established, the acini,in many cases, still retain their pri
Textbook of normal histology: including an account of the development of the tissues and of the organs . lar debris of old epithelialcells, are collected within analbuminous fluid and consti-tute the lactiferous secre-tion. The assumed destruction of the epithelial cells following thedischarge of the oil-globules is improbable, since the cell then simplyenters upon a period of rest and repair, during which its powers ofsecretion are recuperated. In the earliest stage of the activity of themammary gland, when the flow of milk is first established, the acini,in many cases, still retain their primitive condition of solidity ;while the cells at the periphery remain as the secreting elements,those occupying the centre of the acinus undergo fatty degeneration,some become disintegrated, while others are cast off as masses whichconstitute the colostrum-corpuscles found in the milk during thefirst few days. The secretion accumulated within the comparatively large alveoliis carried off by the terminal branches of the ducts, whose wallsconsist of a basement-membrane and a single layer of low colum-. Section of human mammary gland, including sev-eral acini (a) engaged in sluggish secretion of milk;£, epithelial elements containing oil-droplets ; c, inter-acinous connective tissue. 240 NORMAL HISTOLOGY. nar or flattened epithelium. The large excretory canals, thegalactophorous ducts, each of which collects the secretion froman entire lobe, pass as distinct tubes to the nipple ; they possess wallsof considerable thickness, composed of fibrous and elastic connectivetissue, together with some unstriped muscle derived from the lining epithelial cells are columnar to within a few millimetresof the external openings of ducts, where the epithelium becomesstratified and continuous with the epidermis. The fifteen to twentyexcretory ducts, after a longer or shorter course, converge towardsthe areola, within whose area they undergo considerable dilatationto form the ampullae, w
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Keywords: ., bookauthorpiersolgeorgeageorgea, bookcentury1800, bookdecade1890
