Human Breast : A Transplant Organ Consisting Of Lobular Organization
1670 WordsMay 6, 20157 Pages
Human breast is a glandular organ comprising of lobular organization. A breast lobe has a lone lactiferous duct which branches in various segmental ducts with thousands of terminal ducts and lobules and ultimately opening at the nipple. Within the breast, the epithelial structure conquers a pyramid-like tissue space with the nipple at its tip and a broad base. As human breast is a pair, the lobes are recognized as individual units without any connections between them. It has been observed that the number of lobes, in a women’s lifetimes, remains constant even though the size varies based on progressive and regressive process that involving the role of age and hormonal status . In the second trimester of the embryonic development the primary ectoderm produces a bud like out growth known as the primordium nipple. During 21st-25th week of gestation, secondary buds develop into the underneath mesenchyme and slowly forms the breast166. But breasts continue to develop during fetal life with formation of fresh projections and the exhibit duel-cell architecture. The central cells express cytokeratins (CKs) 14 and 19 while the peripheral ones express CK19 only .
As a human infant undergoes development after birth, the breast undergoes involution post influences of maternal hormones. During puberty, stromal elements undergo growth and ramification of ductal tree and lobe formation enlarges the breast167. Based on menstrual cycle, the female breast undergoes cyclical changes during