The Reproductive System

The primary function of the reproductive system is to ensure that the human species survives. All living things reproduce, and it is one of the functions that sets living things apart from non-living things. The continuation of the species will happen by producing an egg and sperm cell and allowing for the transportation of these cells. Another role is to nurture and develop the offspring and to produce hormones.

The Male Reproductive System

This system consists of organs which allows for the production of a new individual. The organs involved are the testes, excretory ducts made up of the epididymis and the vas deferens, glands such as seminal vesicles and the prostate gland and the penis.

Testes

The testes are the principal structure of the male reproductive system. The two egg shaped organs, approximately 2 inches in length are suspended from the body by the scrotal sac, a pouch of skin that allows the testes to remain at an optimum temperature for the development of sperm. The scrotum changes size to be able to maintain the right temperature. The testicles produce and store millions of sperm cells. Around 850 feet of tubules are packed into each testis and is where sperm are produced by meiosis. The testes also produce testosterone, the primary hormone which is involved in puberty. During ejaculation, the muscular movements of the vas deferens and the ejaculatory duct aid the ejection of the sperm.

Excretory Ducts

The epididymis and the vas deferens make up the duct system of the male reproductive system. The epididymis is a c shaped set of coiled tubes that is connected to the vas deferens. They are found at the back of the testes and are where sperm are matured and stored. The vas deferens is a muscular tube that passes up along the side of the testicles and transports the semen.

Glands

The function of the glands in the male reproductive system is to secrete fluids during ejaculation.

  • The seminal vessels have a short duct that joins with the ductus deferens to form an ejaculatory duct that empties into the urethra.
  • The fluid produced assists with the mobility and viability of the sperm, as well as neutralising the acidity in the female reproductive tract.
  • The prostate is a firm, walnut size gland that encircles the urethra as it leaves the urinary bladder. It secretes a thin, milky coloured liquid that enhances the mobility of the sperm. It is of an alkaline substance that counteracts the acidity of the urethra.
  • The paired bulbourethral glands, or sometimes called the Cowper’s glands are about the size of a pea and are found near the base of the penis. During sexual stimulation, theses glands secrete mucus like fluid which neutralises the acidity of the urine residue in the urethra. It also provides some lubrication for the tip of the penis during intercourse.

The Penis

The penis is the sex organ that allows for the passage of both urine and sperm. Apart from the muscles on the tip of the penis, it does not contain bone or muscles.

The penis is made up of three columns of erectile tissue that are wrapped in connective tissue and covered with skin. It has a root, shaft and glans penis, with the root attached to the pubic arch. The shaft is the visible part.

The glans penis is formed at the end and the urethra extends throughout the length of the penis and opens through the external urethral orifice at the tip of the glans penis. The foreskin, a loose folding of skin covers the glans penis.

Seminal Fluid

Seminal fluid contains a mixture of sperm cells and secretions from the accessory glands. In fact around 60% of semen is made up of the secretions from the seminal vesicles, with the prostate gland providing the remainder. Only a small amount comes from the bulbourethral gland and sperm.

In one single ejaculation, the volume of semen can vary from 1.5 to 6.0ml with usually anything between 50 to 150 million sperm per millilitre of semen.