External Male Genitalia
A) Penis: The male organ of copulation made up of three layers of spongy tissue. It contains three parallel cylindrical structures, formed by spaces and cavities. Two of these structures are called cavernous bodies and the third is called the spongy body. During arousal these cavities fill with blood which causes the penis to harden and become erect. The middle of the spongy body runs the urethra which carries urine.
B) Scrotum: Pouch of skin made of multiple layers containing the testicles. Contracts in response to cold, sexual arousal and other stimuli. Regulates temperature for the production of sperm and responds in different ways to the difference in temperature. For example, if it’s too cold, the scrotum pulls the testicles closer to the body. If it's too warm, the testicles hang away from the body.
A *) Glans Penis: Refers to the head of the penis, filled with nerves and is very sensitive compared to the rest of the penis, hence its sexual importance.
A**) Foreskin: Folds of skin covering the penis. Circumcision refers to the removal of the foreskin, some men are not circumcised and others are.
Anus: Separate from the external genitalia nearer to the backside of the body and where waste is excreted. .
Figure 3. Illustration of External Male Genitalia
Internal Male Genitalia
C) Testicles: Glands responsible for the production of sperm and testosterone, the male counterpart hormone. Although both testicles are the same size, the left one usually hangs a little lower than the right one. The testicles are full of seminiferous (producing or conveying semen) ducts, where sperm is produced and matures. Each ejaculate contains millions of sperm, and hundreds surround the egg during fertilization, but generally only one gets to fertilize the egg.
D) Epididymis: Folded tubes located on the testicles where sperm finishes maturing and are stored.
E) Vas Deferens: Two tubes the thickness of cooked spaghetti, during ejaculation, semen passes through the ducts and is expelled through the penis from the body.
F) Prostate: Walnut shaped gland located under the bladder. Contains cells that produce the part of seminal fluid that protects and nourishes sperm. Later on in adult life, this gland may grow larger causing interference with urination (passage of urine) and has to be removed surgically.
G) Seminal Vesicles (Seminal Glands): Two small glands, one on each side of the prostate. Produces the part of the seminal fluid that makes the sperm mobile or able to move.
H) Cowper’s Glands or Bulbourethral Glands: Two pea-shaped structures flanking the urethra. Secrete a pre-ejaculatory fluid that “rids" the urethra of urine waste in preparation for semen during ejaculation. Sometimes this drags sperm from the ducts, which makes pregnancy still possible from sexual intercourse without ejaculation.
I) Urethra: Tube that starts in the neck of the bladder and empties into the urethral aperture. Functions as both the transportation of semen and the elimination of urine.
J) Urethral Aperture: Opening through which urine and semen flow.
Figure 4. Illustration of Internal Male Genitalia
Sources:
Sosa Josué; Sansores Deily; Suárez Lizandra y Rodríguez Lucía. (2018). Illustration of External Male Genitalia. [Figure 1]. Sourced from the book of sexual and reproductive health (P. 11).
Sosa Josué; Sansores Deily; Suárez Lizandra y Rodríguez Lucía. (2018). Illustration of Internal Male Genitalia.. [Figura 2]. Sourced from the book of sexual and reproductive health (P. 12).