From little boys and girls Breasts look the same. With age in girls under the influence of the hormone estrogen (produced in ovaries and adrenals) chest develops. In the male body the hormone estrogen is also present (produced by the adrenal glands), but the number is not enough for full development of breast tissue. Excessive breast development in men, pathology, and medicine called gynecomastia. Causes gynecomastia a lot (more than 30), but the most common is an imbalance of the testosterone–estrogen.

In men, the breast tissue is functionally protects against damage to the heart and lungs. But the heart and lungs protects even more hard tissue – bone, in the form of ribs.

Versions of the presence of Breasts with nipples in men is a lot for visual appeal, as erogenous zone, how vulnerable men and even the mythical (we all were once hermaphrodites). In fact, the answer is you can get by tracing the embryonic development of man. Up to 8 weeks of fetal life between the embryos, male and female, no difference. During this period, all embryos have nipples. After 8 weeks under the influence of hormones, the embryo begins to develop in either the female or the male type, therefore, the nipples of both sexes. A similar process is observed in all mammals, including humans.