In this lesson, we will cover:
The basic structures and parts of the male and female reproductive systems
The functions of the parts of the male and female reproductive systems
The structure of the reproductive system is, of course, different in males and females. However, you may be unaware of most of the organs and smaller structures in the systems that contribute to their overall function.
Female Reproductive System
(Please note that you will not be required to know all of the various parts labelled here)
Labia majora: Larger lip-like external structures that cover and protect the other reproductive structures within.
Labia minora: Smaller lip-like external structures found inside the labia majora. They provide protection to the clitoris, urethra, and vaginal openings.
Clitoris: Sensitive sexual organ located in the uppermost section of the vaginal opening. The clitoris (considered an erectile tissue) contains thousands of sensory nerve endings that respond to sexual stimulation and promote vaginal lubrication. This structure, along with the labia majora, labia minora, and mons pubis constitute the vulva.
Mons Pubis: This is a raised layer of adipose tissue between the skin and the pubic bone. It provides cushioning to the vulva.
Vagina: Fibrous, elastic, muscular canal leading from the cervix to the external portion of the genital canal. The penis enters the vagina during sexual intercourse. It is also the pathway through which menstrual flow exits the body during menstruation. It also serves as the birth canal by stretching to allow delivery of the fetus during childbirth.
Cervix: Opening of the uterus. This strong, narrow structure expands to allow sperm to flow from the vagina into the uterus.
Uterus: Internal organ that houses and nurtures female gametes after fertilization, commonly called the womb. It is attached to the fallopian tubes and the vagina (via the cervix). It surrounds the developing embryo/fetus during pregnancy. The inner lining of the uterus, known as the endometrium, provides support to the embryo during early development. The visceral muscles of the uterus contract during childbirth to push the fetus through the birth canal.
Fallopian tubes: These are muscular uterine tubes that transport egg cells from the ovaries to the uterus. Fertile eggs are released from ovaries into fallopian tubes during ovulation and typically fertilized from there.
Ovaries: Primary reproductive structures that produce female gametes, i.e. eggs (through oogenesis) and sex hormones. There is one ovary on either side of the uterus. As a matter of fact, the ova in the ovaries develop from oocytes which mature during puberty.
Male Reproductive System
(Once again, not all of the labelled organs are necessary for you to memorize)
Penis: This consists of the root (which is attached to the lower abdominal structures and pelvic bones), the visible part of the shaft, and the glans penis (the cone-shaped end). The opening of the urethra (the channel that transports semen and urine) is located at the tip of the glans penis. The base of the glans penis is called the corona. In uncircumcised males, the foreskin (prepuce) extends from the corona to cover the glans penis.
The penis includes three cylindrical spaces (blood-filled sinuses) of erectile tissue. The two larger ones, the corpora cavernosa, lie side by side. The third sinus, the corpus spongiosum, surrounds most of the urethra. When these spaces fill with blood, the penis becomes large and rigid (erect).
Scrotum: A thick-skinned sac that surrounds and protects the testes. The scrotum also acts as a climate-control system for the testes because they need to be slightly cooler than body temperature for normal sperm development. The muscles in the wall of the scrotum (known as the cremaster muscles) relax to allow the testes to hang farther from the body to cool or contract to pull the testes closer to the body for warmth or protection.
Testes: A pair of oval bodies that average about 1.5 to 3 inches (4 to 7 centimeters) in length and 2 to 3 teaspoons (20 to 25 milliliters) in volume. Usually the left testis hangs slightly lower than the right one. The testes have two primary functions:
Producing sperm, which carry the male's genes (spermatogenesis)
Producing testosterone (the primary male sex hormone)
Epididymis: An epididymis consists of a single coiled microscopic tube about 6 meters in length. The epididymis collects sperm from the testis and provides the environment for sperm to mature and acquire the ability to move through the female reproductive system and fertilize an ovum. One epididymis lies against each testis.
Vas deferens- a firm tube that transports sperm from the epididymis. One such duct travels from each epididymis to the back of the prostate and joins with one of the two seminal vesicles.
Urethra: This pathway is the part of the urinary tract that transports urine from the bladder and the part of the reproductive system through which semen is ejaculated. So, it has a sort of dual function.
Prostate: lies just under the bladder and surrounds the urethra. It produces a milky, alkaline fluid that increases sperm motility and empties this fluid (prostatic fluid) of the into the urethra.
Seminal vesicles- These pathways join with the vas deferens to form the ejaculatory ducts, which travel through the prostate. The prostate and the seminal vesicles produce fluid that nourishes the sperm. This fluid constitutes most of the volume of semen, the fluid in which the sperm is expelled during ejaculation. Other fluid that makes up a very small amount of the semen comes from the vas deferens and from Cowper glands in the urethra.
Bulbourethral or Cowper's Glands- Small glands located at the base of the penis. In response to sexual stimulation, these glands secrete an alkaline fluid which helps to neutralize acidity from the vagina and urine in the urethra.
Additional Reading and Sources:
Innerbody Article (male reproductive system)
Innerbody Article (female reproductive system)