Gonads are mixed glands producing gametes and sex hormones. Male gonads (testicles) produce sperm, female gonads (ovaries) produce eggs. Gonads evolved independently several times
System develops from immature at birth to produce offspring. Ovaries produce eggs and secrete hormones. Fallopian tubes transport eggs from ovaries to uterus. Uterus provides protection and nourishment for developing embryo. Vagina serves as birth canal and allows sexual intercourse
Sex differences result from different chromosome complements and hormone exposure. Females have XX chromosomes, males have XY chromosomes. X-chromosome inactivation enables equal gene expression in females
The uterus is a pear-shaped, muscular organ located in the lesser pelvis. It measures approximately 7.5 cm in length and weighs 30-40 g. Divided into body and cervix, with a midpoint isthmus. Attached to various ligaments and muscles, related to bladder and rectum
Sperm is male reproductive cell produced by most animals. Most sperm are flagellated, except nematodes and certain mollusks. Sperm production occurs in testes of higher vertebrates
Cervical os is part of cervix connecting uterus to vagina. Cervix is about an inch long and can vary during lifetime. External os is near vagina, internal os near uterus