A convoluted duct that sits on the superior pole of each testis. Sperm are stored in the epididymis during the maturation process.

The vasa deferentia (singular: vas deferens) bring sperm from the testes to the seminal vesicles. The seminal vesicles contribute fluid to semen during ejaculation.

A thick-walled tube in the spermatic cord that transports sperm from the epididymis to the ejaculatory ducts in the prostate gland. The ductus deferens traverses the superficial inguinal ring, coursing through the inguinal canal, and enters the pelvis through the deep inguinal ring lateral to the inferior epigastric artery. En route to the ejaculatory duct, the ductus deferens crosses the medial side of the umbilical artery and the obturator neurovascular structures. Sympathetic nerves from the inferior hypogastric plexus cause peristaltic contractions in the thick smooth muscle wall and propel sperm during ejaculation.

Lobular glands located on the base of the bladder. During emission and ejaculation, the seminal vesicles empty their secretions (e.g., fructose, citric acid, prostaglandins, and fibrinogen) into the ejaculatory duct, along with sperm from the ductus deferens. Seminal vesicle secretions add substantially to the volume of semen.

Formed by the union of the ductus deferens and ducts from the seminal vesicles. The ejaculatory ducts open into the prostatic urethra.

Composed of five lobes, all surrounding the prostatic urethra. The prostate gland is located superior to the pelvic diaphragm and anterior to the rectum. The prostate gland secretes a milky fluid that contributes to the bulk of the semen.

The prostate is gland located between the bladder and the penis. The prostate is just in front of the rectum. The urethra runs through the center of the prostate, from the bladder to the penis, letting urine flow out of the body.

The prostate secretes fluid that nourishes and protects sperm. During ejaculation, the prostate squeezes this fluid into the urethra, and it’s expelled with sperm as semen.

 

 

 

• The penis is the male copulatory organ, composed of erectile tissue, transports urine and semen via the urethra; the penis is highly innervated by perineal nerve branches and becomes engorged with blood and erects during stimulation.

   

  The anatomy of the urethra in men can be divided into the following segments proceeding from cephalad to caudad: prostatic, membranous, bulbous (the area between the pelvic floor and the penoscrotal junction), and penile.

  The penis erects in the anatomical position (i.e., when the penis is flaccid, its dorsal surface is positioned anteriorly).

  The penis consists of the following parts:

  • Glans penis. Formed by the terminal part of the corpus spongiosum; projects posteriorly over the end of the corpora cavernosa; covered by a free fold of skin called the prepuce. Circumcision is the surgical removal of the prepuce.

  • Body (corpus). The free pendulous part of the penis; contains the single corpus spongiosum and the paired corpora cavernosa.

    • Corpus spongiosum. Erectile tissue surrounding the spongy urethra (transports urine and semen) on the ventral surface of the penis; expands distally into the glans penis. During an erection, the corpus spongiosum prevents the urethra from being pinched closed, thereby maintaining the urethra open for transporting semen during ejaculation.

    • Corpora cavernosa. Paired erectile tissues that form most of the body of the penis on its dorsal surface; less pliable than the corpus spongiosum because the corpora cavernosa fill with the majority of blood during erection.

  • Root. The attached part of the penis consisting of the bulb and two crura:

    • Bulb of the penis. Attached in the midline to the perineal membrane; the bulb is the dilated root of the corpus spongiosum and is surrounded by the bulbospongiosus muscle.

    • Crura of the penis. Paired structures attached to the ischiopubic rami on either side of the bulb; the crura are the roots of the corpora cavernosa and are surrounded by the ischiocavernosus muscles.