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Male Reproductive System-Anatomy and Function

November 4, 2023
written by Sidra Batool

The male reproductive system consists of a number of external and internal organs that work together to produce, nourish, transport, and discharge sperm for reproduction.

image showing Male Reproductive System

Outside the body, the male reproductive system includes the penis, scrotum, and testicles. The penis is used for sex and to pee. The scrotum is a pouch that holds the testicles and helps keep them cool. The testicles make sperm and a hormone called testosterone.

Inside the body, the male reproductive system includes the epididymis, vas deferens, seminal vesicles, prostate gland, and bulbourethral glands. These organs make and store fluids that mix with sperm to make semen. They also move sperm from the testicles to the penis, where it is released during sex.

The male reproductive organs work as an integrated system to generate, mature, and release sperm, which can fertilize a female egg to produce offspring. This process is regulated by hormones like follicle-stimulating hormone and testosterone. Overall, the male reproductive system allows organisms to participate in sexual reproduction through the delivery of sperm.

Anatomy of Male Reproductive System

The male reproductive system is responsible for the production and delivery of sperm. The external structures produce and protect the sperm, while the internal structures store and transport sperm, and contribute fluids to semen. Together, these organs allow for ejaculation of sperm during sexual arousal.

Here are the main parts of male reproductive structure:

1. Penis

The penis is the male organ used for sexual intercourse and urination. It has three main parts:

  • Root: The root of the penis is the thickest part, which attaches the penis to the pelvic bone.
  • Shaft: The shaft is the long, cylindrical part of the penis. It contains three columns of erectile tissue: two corpora cavernosa and the corpus spongiosum. The corpora cavernosa are located on either side of the penis and fill with blood during an erection, causing the penis to harden and become erect. The corpus spongiosum contains the urethra, which is a tube that carries both urine and semen.
  • Glans: The glans is head of the penis. It is covered by a thin, sensitive layer of skin called the foreskin. The foreskin may be removed in a procedure called circumcision.

2. Scrotum

The scrotum is a sac of skin that hangs behind the penis. It contains the testicles and helps to regulate their temperature. The scrotum is made up of two layers of skin: a thin, outer layer and a thicker, inner layer. The inner layer contains muscles that can contract to tighten the scrotum and move the testicles closer to the body in cold weather.

3. Testicles

The testicles are oval-shaped reproductive glands located in the scrotum. Their key functions are producing sperm cells and the hormone testosterone.

Testosterone is the male sex hormone responsible for the development of male secondary sex characteristics during puberty, such as facial hair growth and deepening of the voice.

Inside each testicle are hundreds of lobules divided by connective tissue. The lobules contain seminiferous tubules – coiled structures where sperm cells develop through the process of spermatogenesis.

From puberty through adulthood, the seminiferous tubules constantly generate immature sperm cells that mature into fully functional, motile sperm.

4. Vas deferens

The vas deferens is a long, muscular tube that transports sperm from the epididymis to the urethra. It originates from the back of each testicle, then coils and travels upward through the inguinal canal – a passageway in the groin area.

Inside the pelvic cavity, the two vas deferens tubes join together to form a single tube called the ejaculatory duct. This duct passes through the prostate gland and connects to the urethra.

When a male reaches sexual climax, contractions force sperm from the vas deferens into the ejaculatory ducts and urethra. This allows sperm to exit the body through the penis during ejaculation. So the vas deferens provides the crucial role of carrying mature sperm from the testes up to the urethra for ejaculation.

5. Ejaculatory ducts

The ejaculatory ducts are two short tubes that connect the vas deferens and seminal vesicles to the urethra. The ejaculatory ducts pass through the prostate gland before entering the urethra.

6. Seminal vesicles

The seminal vesicles are two glands that produce a fluid that nourishes and protects the sperm. The seminal fluid also helps to make the semen more alkaline, which can help the sperm to survive in the acidic environment of the vagina.

7. Prostate gland

The prostate gland is a small, walnut-shaped organ situated below the bladder and surrounding the urethra. Its main function is to secrete a fluid that contributes to semen.

Specifically, the prostatic fluid nourishes and protects sperm cells, providing nutrients and buffering the acidity of the female reproductive tract to optimize the sperm’s environment. The alkaline prostatic fluid balances out the usually acidic pH of semen and vaginal secretions.

8. Bulbourethral glands

The bulbourethral glands are two small glands that are located below the prostate gland. The bulbourethral glands produce a lubricating fluid that is released into the urethra during ejaculation. This fluid helps to neutralize the acidity of the urine and lubricate the urethra, which can make ejaculation more comfortable.

9. Urethra

The urethra is a tube that carries both urine and semen. It runs through the center of the penis and exits at the tip of the glans.

How it Works?

Male system produces and delivers sperm through a number of coordinated processes involving the hormones, accessory glands, and ducts that support reproduction through intercourse.

Here is how the male reproductive system works:

  1. The process begins in puberty when the hypothalamus signals the pituitary gland to release hormones that stimulate the testicles.
  2. The testicles produce the hormone testosterone which supports sperm production and development of male characteristics.
  3. In the testicles, sperm develop from immature cells into mature sperm through the process of spermatogenesis, which takes about 64 days.
  4. Mature sperm are transported from the testicles to the epididymis where they are stored until ejaculation.
  5. During arousal, the sperm move from the epididymis through the vas deferens to the ejaculatory duct. Secretions from the seminal vesicles, prostate, and other glands are added to the sperm to produce semen.
  6. The semen collects in the urethral bulb and prostate gland. Contractions during ejaculation force the semen through the urethra and out the penis.
  7. The ejected semen deposits sperm into the female reproductive tract during intercourse, allowing fertilization of an egg to occur.
  8. If fertilization happens, the embryo can implant in the uterus and develop into a fetus. If not, the uterine lining is shed about 2 weeks later during menstruation.
  9. The cycle continues with sperm production and maturation in the testicles preparing for the next potential fertilization.