2006-12-13 01:55:44 · 3 answers · asked by jamess007 2 in Science & Mathematics ➔ Biology
The answer is that as embryos men and women have similar tissues and body parts. If anything the embryo follows a 'female template'. That is why nipples are present in both sexes. It is the effect of the genes, the Y chromosome and the hormone testosterone that brings about the changes and masculinises the embryo. Testosterone promotes the growth of the penis and testicles. Because nipples are there before this process begins the nipples stay!
Nipples and breast tissue have no function as such except for perhaps protecting the heart and lungs from injury.
It is possible for men to produce breast milk
This is because a certain amount of 'female type' hormones called estrogens are present in all men. If hormones become unbalanced because of disease or malfunction then breast tissue can grow (gynecomastia- abnormal enlargement of breasts,) and men can produce milk.
Gynacomastia is more commonly seen in adolescence, a period in development when hormones fluctuate a lot. It is also seen in some men with liver disease and in alcoholics.
Men can get breast cancer as well as women.
2006-12-13 02:15:57 · answer #1 · answered by veerabhadrasarma m 7 · 0⤊ 0⤋
Men have nipples because they are fomed by the fetus (at around 7 weeks) before any sexual differentiation occurs. All fetuses are morpholgically female until the Y chromosome kicks in in males and begins sexual differentiation. There is no medical purpose for nipples in males.
2006-12-13 03:43:24 · answer #2 · answered by dtbrantner 4 · 0⤊ 0⤋
Because they're mammals and haave mammary glands. Mens just don't develop.
2006-12-13 02:22:31 · answer #3 · answered by JenFrat 2 · 0⤊ 0⤋