PHSI 208 Lecture 1: rep 1
Document Summary
Topics: sex determination, sexual differentiation (internal and external), gametogenesis. One area of physiology in which we like to think of ourselves as significantly advanced over other animals is our ability to reproduce. Humans mate for both pleasure and procreation, and does not only occur during fertile periods. Humans are sexually dimorphic, meaning males and females have distinct physical characteristics. Male and female sex organs consist of three sets of structures: Humans have 23 pairs of chromosomes: 22 pairs of autosomes and one pair of sex chromosomes. Each egg produced by a female (xx) has an x chromosome. Sperm produced by a male (xy) have either an x chromosome or a y chromosome. Each nucleated cell of the body except gametes contains 23 pairs of chromosomes, making 46 total. Gametes contain 23 single chromosomes (haploid) and have only 1 copy. The 22 pairs of autosomes are involved in the direct development of the human body.
