There exists also appreciable variation in measurement among folks. Permanent breast expansion in the course of puberty is brought on by estrogens along side the growth hormone. Feminine humans are the one mammals that permanently produce breasts at puberty; all other mammals develop their mammary tissue in the course of https://grok.com/share/c2hhcmQtMw%3D%3D_5ad6450c-533d-442c-a09c-9f7bce1babfb