The breast is fundamentally a sweat gland that undergoes stages of maturation and development throughout a woman's life, influenced by hormonal changes.

“uh the breast uh is a gland um it is fundamentally a sweat gland if you look at the you know pure embryology of it and it is the defining feature of what it is to be a mammal and as you alluded to the breast goes through uh different stages of maturation and development in the life of a woman and um it begins as um sort of a a quiescent area of tissue and then during puberty uh because of the hormonal changes uh develops um enlargement and maturation of the glands such that they become able to eventually secrete milk if the if the woman becomes pregnant”