Reproductive System

Both male and female reproductive systems have organs called gonads that produce gametes.

A gamete is a haploid cell that combines with another haploid gamete during fertilization, forming a single diploid cell called a zygote.

Besides producing gametes, the gonads also produce sex hormones. Sex hormones are endocrine hormones that control development of sex organs before birth, sexual maturation at puberty, and reproduction once sexual maturation has occurred.

Undifferentiated embryonic tissues develop into different structures in male and female fetuses. Structures that arise from the same tissues in males and females are called homologous structures.

The main sex hormones are testosterone in males and estrogen in females.

The main sex hormones are testosterone in males and estrogen in females.

Sex hormones, in turn, lead to the growth and maturation of the reproductive organs, rapid body growth, and the development of secondary sex characteristics. Secondary sex characteristics are traits that are different in mature males and females, but are not directly involved in reproduction. They include facial hair in males and breasts in females.

The two testes (singular, testis) hang between the thighs in a sac of skin called the scrotum. The testes produce both sperm and testosterone.

The two testes (singular, testis) hang between the thighs in a sac of skin called the scrotum. The testes produce both sperm and testosterone.

Resting atop each testis is a coiled structure called the epididymis (plural, epididymes). The function of the epididymes is to mature and store sperm.

The penis is a tubular organ that contains the urethra.

The ducts, which include the vas deferens (also called the ductus deferens), transport sperm from the epididymis to the urethra.

The glands, which include the prostate gland and seminal vesicles, produce fluids that become part of semen.

The process of producing sperm is known as spermatogenesis.

The main structures of the female reproductive system are internal to the body. They include the paired ovaries, which are small, ovoid structures that produce eggs and secrete estrogen.

The two Fallopian tubes start near the ovaries and end at the uterus. Their function is to transport eggs from the ovaries to the uterus.

The two Fallopian tubes start near the ovaries and end at the uterus. The uterus is a pear-shaped muscular organ that functions to carry a fetus until birth.

The vagina is a tubular tract connecting the uterus to the outside of the body.

The placenta is a temporary organ that consists of a mass of maternal and fetal blood vessels through which the mother’s and fetus’s blood exchange substances.

The process of producing eggs in the ovaries of a female fetus is called oogenesis.