Chapter 6: Male Sexual Anatomy and Physiology

male copulatory and urinary organ, used both to urinate and move spermatozoa out of the urethra through ejaculation

penis

thick, whitish secretion of the male reproductive organs, containing spermatozoa and secretions from the seminal vesicles, prostate, and Cowper’s glands

semen

hardening of the penis caused by blood engorging the erectile tissue

erection

areas in the penis that fill with blood during erection

corpora cavernosa

meaning “spongy body,” the erectile tissue in the penis that contains the urethra

corpus spongiosum

flaring, enlarged region at the end of the penis

glans penis

ridge of the glans penis

corona

fold of skin on the underside of the penis

frenulum

opening of the penis through which urine and semen are expelled

urethral opening or meatus

fold of skin that covers the glans penis; also called the prepuce

foreskin

external pouch of skin that contains the testicles

scrotum

“suspender” muscle that raises and lowers the scrotum to control scrotal temperature

cremaster muscle

production of sperm in the testes

spermatogenesis

tightly coiled duct located in the testes where spermatozoa are produced

seminiferous tubule

mature sperm cell

spermatozoon

immature sperm cell that will develop into a spermatocyte

spermatogonium

intermediate stage in the growth of a spermatozoon

spermatocyte

cells that make up the final intermediate stage in the production of sperm

spermatids

tail-like end of a spermatozoon that propels it forward

flagellum

cells in the testes that produce testosterone; also called interstitial cells

leydig cells

comma-shaped organ that sits atop the testicle and holds sperm during maturation

epididymis

one of two long tubes that convey the sperm from the testes and in which other fluids are mixed to create semen

vas deferens

reflex ejection or expulsion of semen from the penis

ejaculation

base of the vas deferens, where the vas hooks up over the ureter of the bladder

ampulla

pair of pouchlike structures lying next to the urinary bladder that secrete a component of semen into the ejaculatory ducts

seminal vesicles

tube that transports spermatozoa from the vas deferens to the urethra

ejaculatory duct

walnut-sized gland that wraps around the urethra as it comes out of the bladder, contributing fluid to the semen

prostate gland

pair of glands located under the prostate gland on either side of the urethra that secrete a fluid into the urethra

Cowper’s (or bulbourethral) gland

involuntary ejaculation during sleep

nocturnal emissions

condition in which the testes fail to descend into the scrotum

cryptorchidism

twisting of a testis on its spermatic cord, which can cause severe pain and swelling

testicular torsion

persistent and painful erection

priapism

abnormal calcifications or fibrous tissue buildup in the penis, which may cause painful curvature, often making sexual penetration impossible

Peyronie’s disease

condition in which the intestines bulge through a hole in the abdominal muscles of the groin

inguinal hernia

tube-like structure through which the testes descend into the scrotum

inguinal canal

condition in which there is an excessive accumulation of fluid within the tissue surrounding the testicle, which causes a scrotal mass

hydrocele

common enlargement of the prostate that occurs in most men after about age 50

benign prostatic hypertrophy

blood test used to detect cancer that measures levels of molecules that are overproduced by prostate cancer cells

prostate-specific antigen

surgical removal of the prostate

radical prostatectomy

surgery that uses freezing techniques to destroy part of an organ

cryosurgery