Male reproductive system

The male reproductive system (Latin: systema genitale masculinum) is composed of a series of various organs, glands and ducts that all together work to produce, store and deliver sperm to fertilize the female egg and, as a result, produce offspring. Moreover, these organs are responsible for giving sexual pleasure, and some of them also produce essential hormones called androgens that are responsible for male development. Overall, the male reproductive organs can be subdivided into two groups - internal and external genital organs.

External male genital organs

The external male genital organs are found outside the male body, and these include the penis and the scrotum:

• Penis - an unpaired organ responsible for the excretion of urine and sperm. It is made up of three parts: root (the base or proximal portion of the penis that attaches it to the pubic symphysis and bones of the pelvis), shaft or body (long, cylindrical-shaped part of the penis formed by three columns of erectile tissue (one spongious and two cavernous bodies) that fill with blood during sexual arousal to cause erection) and glans (the most distal rounded tip that is partially covered by a loose double skin fold called the foreskin or prepuce). Additionally, through the penis goes the urethra. Although the urethra is an organ of the urinary system, it carries both - urine and semen - out of the body.
• Scrotum - a sac of skin and smooth muscles that holds paired testicles, epididymides, and the lower portions of the spermatic cords. It is located below the penis and is divided into two compartments, each of which contains one testicle and epididymis. Overall, the scrotum helps to regulate the temperature of the testicles, which is an important physical factor that can affect sperm production.

Internal male genital organs

The internal genital organs of a male reproductive system are found within the body, and they include the testicles, epididymides, vasa deferentia, seminal vesicles, prostate, ejaculatory ducts and bulbourethral glands.

• Testicle (testis) - two small, oval-shaped organs that are found within the scrotum; they produce sperm and are responsible for the synthesis of the male sex hormone testosterone; each testicle is surrounded by several layers of tissue;
• Epididymis - a long paired coiled tube that lies on the top and posterior aspect of each testicle; it is composed of a series of ducts and is a site where spermatozoa mature and are stored;
• Vas deferens (ductus deferens) - a long paired muscular tube that carries sperm from the epididymis to the ejaculatory duct; at its distal ends, each vas deferens is slightly dilated, and this enlargement is known as ampulla; each ampulla converges with the excretory duct of the seminal vesicle to form the ejaculatory duct;
• Seminal vesicle - two elongated tube-like small glands located posterior to the prostate and inferior to the fundus of the bladder; they produce a fluid that nourishes and protects sperm and forms the majority of the semen;
• Prostate - a small unpaired gland located inferior to the bladder; it is roughly the size and shape of a walnut and surrounds the urethra; it produces a thin, milky fluid that also participates in the formation of the semen; overall, the fluid produced by the prostate contains various substances that help to nourish and protect sperm;
• Ejaculatory duct - a pair of short, muscular tubes that connect the ductus deferens to the urethra; this duct goes through the prostate and joins the urethra close to the apex of the gland; these ducts are responsible for propelling sperm and seminal fluid into the urethra during ejaculation;
• Bulbourethral gland (Cowper's gland) - two small pea-shaped glands located behind the membranous portion of the urethra inferior to the prostate and near the root of the penis; it produces a fluid that lubricates the urethra and helps to neutralize any acidity in the urethra.

Functions of male reproductive system

The male reproductive system is primarily responsible for producing and delivering sperm. The testicles produce millions of sperm daily, which are then stored and matured in the epididymis.

When a man becomes sexually aroused, the muscles surrounding the epididymis and ductus deferens contract, forcing sperm into the ejaculatory duct. The seminal vesicles, prostate and bulbourethral glands produce fluids that mix with sperm creating semen. The semen is further ejaculated out of the body during orgasm via the urethra going through the penis.

Overall, the male reproductive organs serve several essential functions, and here is a summary of some of the key functions:

• Production of sperm - the testes are responsible for producing sperm; the process of sperm production is called spermatogenesis.
• Storage and transportation of sperm - the epididymis serves to store and transport sperm from the testicle to the ductus deferens; further sperm is transported to the outside of the body via the ductus deferens, ejaculatory duct and urethra;
• Production of semen - various sex glands, including the seminal vesicles, prostate, and bulbourethral glands, produce and secrete fluids that combine with sperm to form semen; these fluids contain nutrients that nourish sperm and help spermatozoa to survive in the female reproductive tract;
• Ejaculation - the process of ejaculation involves the contraction of muscles in the male reproductive system, which propels semen out of the body through the urethra;
• Sexual pleasure function - the male reproductive system plays a crucial role in sexual function, including arousal, erection, and orgasm;
• Secretion of hormones - the testicles also secrete male sex hormones such as testosterone; it plays a crucial role in the development of male secondary sexual characteristics - facial and body hair growth, deepening of the voice, and muscle mass enlargement.

To sum up, the male reproductive system is essential for the continuation of the human species, as it enables men to produce and deliver sperm for fertilization of the female egg.