Male and Female Reproductive Systems

Reproductive System

In simple terms, reproduction is the process by which organisms create descendants. This miracle is a characteristic that all living things have in common and sets them apart from nonliving things. But even though the reproductive system is essential to keeping a species alive, it is not essential to keeping an individual alive.

In human reproduction, two kinds of sex cells or gametes are involved. Sperm, the male gamete, and a secondary oocyte (along with first polar body and corona radiata), the female gamete must meet in the female reproductive system to create a new individual. For reproduction to occur, both the female and male reproductive systems are essential. It is a common misnomer to refer to a woman’s gametic cell as an egg or ovum, but this is impossible. A secondary oocyte must be fertilized by the male gamete before it becomes an “ovum” or “egg.”

While both the female and male reproductive systems are involved with producing, nourishing and transporting either the oocyte or sperm, they are different in shape and structure. The male has reproductive organs, or genitals, that are both inside and outside the pelvis, while the female has reproductive organs entirely within the pelvis.

The Male Reproductive System

The male reproductive system consists of the testes and a series of ducts and glands. Sperm are produced in the testes and are transported through the reproductive ducts. These ducts include the epididymis, vas deferens, ejaculatory duct and urethra. The reproductive glands produce secretions that become part of semen, the fluid that is ejaculated from the urethra. These glands include the seminal vesicles, prostate gland, and bulbourethral glands.

Figure 1. The reproductive structures of the human male are shown.

Table 1 describes the major components of the male reproductive system.

Table 1. Components of the Male Reproductive System
Structure	Location & Description	Function
Bulbourethral glands (2)	Pea sized organs posterior to the prostate on either side of the urethra.	Secretion of gelatinous seminal fluid called pre-ejaculate. This fluid helps to lubricate the urethra for spermatozoa to pass through, and to help flush out any residual urine or foreign matter. (< 1% of semen)
Epididymis	Tightly coiled duct lying just outside each testis connecting efferent ducts to vas deferens.	Storage and maturation of sperm.
Penis	Three columns of erectile tissue: two corpora cavernosa and one corpus spongiosum. Urethra passes through penis.	Male reproductive organ and also male organ of urination.
Prostate gland	Surrounds the urethra just below the urinary bladder and can be felt during a rectal exam.	Stores and secretes a clear, slightly alkaline fluid constituting up to one-third of the volume of semen. Raise vaginal pH.(25-30% of semen)
Seminal vesicles (2)	Convoluted structure attached to vas deferens near the base of the urinary bladder.	About 65-75% of the seminal fluid in humans originates from the seminal vesicles. Contain proteins, enzymes, fructose, mucus, vitamin C, flavins, phosphorylcholine and prostaglandins. High fructose concentrations provide nutrient energy for the spermatozoa as they travel through the female reproductive system.
Testes	Inside scrotum, outside of body.	Gonads that produce sperm and male sex hormones.Production of testosterone by cells of Leydig in the testicles.
Urethra	Connects bladder to outside body, about 8 inches long.	Tubular structure that receives urine from bladder and carries it to outside of the body. Also passage for sperm.
Vas deferens	Muscular tubes connecting the left and right epididymis to the ejaculatory ducts to move sperm. Each tube is about 30 cm long.	During ejaculation the smooth muscle in the vas deferens wall contracts, propelling sperm forward. Sperm are transferred from the vas deferens into the urethra, collecting fluids from accessory sex glands en route

The Female Reproductive System

Reproduction can be defined as the process by which an organism continues its species. As noted earlier, in the human reproductive process, two kinds of gametes are involved: the male gamete (sperm) and the female gamete (egg or ovum). These two gametes meet within the female’s uterine tubes located one on each side of the upper pelvic cavity, and begin to create a new individual. The female needs a male to fertilize her egg; she then carries offspring through pregnancy and childbirth.

Figure 2. The reproductive structures of the human female are shown. (credit a: modification of work by Gray’s Anatomy; credit b: modification of work by CDC)

Female Reproductive System

Produces eggs (ova)

Secretes sex hormones

Receives the male spermatazoa during

Protects and nourishes the fertilized egg until it is fully developed

Delivers fetus through birth canal

Provides nourishment to the baby through milk secreted by mammary glands in the breast

The major components of the female reproductive system are shown in Table 2.

Table 2. Components of the Male Reproductive System
Structure	Location & Description	Function
Ovaries (2)	Ovoid structures on either side of the uterus in the pelvic cavity	Primary sex organs of female; contain ovarian follicles that contain the oocytes. Oocytes are released during the ovulation stage of the menstrual cycle.
Fallopian Tubes (2)	Extend from lateral ares of uterus to near the ovaries	Transport oocyte to uterus after fertilization and are the sites where fertilization by sperm actually occurs
Uterus	Pear shaped structure divided into the fundus and the cervix	Site of fetal development during gestation
Vagina	Located between rectum and urethra; smooth muscle lined with an epithelial mucous membrane	Path for menstrual blood and tissue to leave the body, as well as the fetus during childbirth. Produces a variety of secretions for lubrication and receives secretions that facilitate fertilization.
Vulva	Externally located: labia majora and minora, mons pubis, clithoris, vestibule, greater and lesser vestibular glands	Sexual function: heavily innervated and provide pleasure when properly stimulated.
Perineum	Area between vagina and anus	Helps form the muscular floor of pelvis; can be torn during vaginal childbirth
Mammary glands	Superficial to pectoral muscles	Provide nourishment to the baby through milk secretions