Male Reproductive System

The male reproductive system includes testes, external genitalia, i.e. penis and accessory ducts, viz., rete testis, vasa efferentia, epididymis and vas deferens. Unlike the female reproductive system, most parts of the male reproductive system are located outside the body. Apart from these parts, the male reproductive system also includes the male accessory glands that are prostate glands, seminal vesicles and bulbourethral glands.

Labelled Diagram of Male Reproductive System

Let’s have a look at the male reproductive system that represents different parts or organs of the male reproductive system with a labelled diagram.

Male reproductive system diagram

Male reproductive system

The male reproductive system includes the testes, scrotum, spermatic ducts, male accessory glands, and penis. All these organs work together to produce sperms, the male gamete, male sex hormones and other components of semen.

• Penis and Urethra are a part of both the reproductive and urinary systems.

• Scrotum, seminal vesicles, vas deferens, testicles (testes), and prostate constitute all the remaining male reproductive system.

The Penis has a root that is connected to the structures of both the pelvic bones and lower abdominal (the shaft’s visible part) glands that has a cone-shaped end. The urethra’s opening is the channel that carries semen and urine and lies at the tip of the penis. The base of the penis is known as Corona.

Penis

It is the male external genitalia. It involves three cylindrical spaces of erectile tissue. The two of which are larger, the corpora cavernosa lie side by side and the third one is the sinus, called corpus spongiosum covers the urethra. The penis becomes rigid when these spaces are filled with blood. The tissues help in the erection of the penis and facilitate insemination. The foreskin covers the enlarged end of the penis called glans penis.

Scrotum

It is a sac of thick skin that protects and surrounds the testes. It also controls the temperature of the testes since they have to be at a slightly lower temperature than the body temperature for suitable sperm creation. The muscles in the wall allow the testes to hang far from the body or shrink to pull them closer for protection and warmth.

Testes

A pair of testes are present in humans. Testes are present outside the body in a pouch called the scrotum. They are oval bodies, around 4 to 5 cm in length and 2 to 3 cm wide. Generally, the left testis hangs slightly lower than the right one.

The two primary functions of tests are as follows:

• Producing testosterone – a male sex hormone.
• Producing sperms or spermatogenesis – a carrier of man’s genes.

Each testis contains about 250 testicular lobules or compartments.

Sperms are produced in the seminiferous tubules. Each testicular lobule contains one to three seminiferous tubules. Seminiferous tubules are lined by two types of cells:

• Spermatogonia or male germ cells – They undergo spermatogenesis to produce sperm.
• Sertoli cells – They provide nutrition to germ cells.

Leydig cells or interstitial cells are present outside the seminiferous tubules in the interstitial spaces. They secrete male sex hormones or androgens, e.g. testosterone.

Male Sex Accessory Ducts

Rete testis, vasa efferentia, epididymis and vas deferens are male sex accessory ducts. Seminiferous tubules open into rete testis, which leads to vasa efferentia. Vasa efferentia opens into the epididymis and epididymis leads to vas deferens. It leads to the ejaculatory duct along with a duct from the seminal vesicle. Sperms mature in these ducts. Sperms are stored and transported through these ducts.

Urethra

It is a tube-like structure that connects the urinary bladder to the urinary meatus. In males, the urethra travels through the penis and is mainly involved in two main functions:

• This region is included in the urinary tract that takes urine from the bladder where semen is ejaculated.
• The Prostate exists beneath the bladder and covers the urethra. The prostate grows larger with age. If the prostate grows too much, it can block the urine flow through the urethra and be responsible for some urinary symptoms.

Male Accessory Glands

The male accessory glands include seminal vesicles, prostate and bulbourethral glands. A pair of seminal vesicles are present. The Seminal vesicles are present over the prostate, linked with the vas deferens to create the ejaculatory ducts that travel through the prostate. The male accessory glands generate fluid that nourishes the sperm. It is called seminal plasma. This fluid is rich in fructose, calcium and certain enzymes. It constitutes the maximum volume of the semen, wherein the sperm is ejected during ejaculation.