It is very obvious that men and women are different anatomically because of their biology and genetics. A clear example of these differences is simply, women have breasts and men do not. Women’s bodies develop and grow to bear children and men’s bodies do not, so as both sexes mature, their anatomy differs as they are responsible for different body functions. Some biological features are more subtle however, and are not as noticeably different, although they are the reason for some functional differences between men and women.

For example, men’s collagen fibers are more crisscrossed and dense than women’s. Regardless of age, men have a higher collagen density, which is why women appear to age faster and are more prone to cellulite. After the age of 30, the collagen in both men and women decreases at the same rate, but after menopause, the rate quickens for women for about five years. Another subtle difference is their blood flow and vascular systems. Women’s blood flow is closer to their core, while men’s blood flows more evenly throughout their bodies. Some experts believe that women hold heat in their core, where the uterus and heart are, to protect “the babymaking zone.” Also for this reason, women tend to have colder hands and feet than men.