From the Latin word for 

“tail,” the penis is the external 

male genitalia.

 The 

pouch of skin that holds the 

testicles.

 From the Latin word 

for “acorn,” the glans is the 

enlarged head of the  

penis.

 The raised edge of the 

penis that separates the glans 

from the shaft.

 The 

opening at the tip of the glans.

 The thin strip of flesh 

on the underside of the penis 

that connects the shaft to the 

glans.

 The fold of skin that 

covers the head of the penis in 

uncircumcised males.

 A thick and malodorous

substance that can 

accumulate under the foreskin 

in uncircumcised men.

 The surgical 

removal of the foreskin of the 

penis.

 Two 

cylinders of erectile tissue that 

run along the upper part of the 

penis.

 Erectile 

tissue that runs along the underside

of the penis and encloses 

the urethra.

 Tubular structure that serves as a 

passageway for both urine and 

semen.

 The inner branches of 

the penile shaft.

Exercises that involve clenching 

and unclenching of the muscles 

of the pelvic foor.

The sensitive skin between the 

genitals and the anus.

 The 

hair, often somewhat coarse and 

stif, that grows in the pubic 

region just above the external 

genitals.

 The male 

gonad that produces sperm and 

testosterone.

 The reproductive organ 

that produces gametes.

 The male or female 

reproductive cell—the sperm or 

egg.

 The cord-like 

structure containing blood 

vessels, nerves, and the vas 

deferens that runs from the 

abdomen down to each testicle.

Long, 

convoluted tubes in the testes 

where sperm is produced.

Supportive cells that secrete 

hormones, nurture developing 

sperm, and form the blood– 

testes barrier.

 Cells that synthesize 

and secrete testosterone and 

other androgens. “Interstitial” is 

a medical term that means “to 

stand between”; interstitial cells 

of Leydig are found between the 

seminiferous tubules of the 

testes.

The portion of the ejaculatory 

pathway where sperm mature 

and learn to swim.

 The 

tube that carries sperm from 

each epididymis to the ejaculatory duct.

 The sac-like swelling 

at the end of each vas deferens.

 The cutting of the 

vas deferentia to prevent sperm 

from entering the ejaculate.

 When used as a noun, 

it is another word for semen.

 The part of 

the ejaculatory pathway that 

passes through the prostate and 

connects the vas deferens and 

the urethra.

 The white milky 

substance produced by the 

seminal vesicles, prostate gland, 

and Cowper’s gland that 

provides nutrition and protec-

tion for the sperm.

 The fuid 

released during ejaculation, 

which is made up of sperm and 

seminal fuid.

 Two glands 

that produce a thick, alkaline 

secretion that makes up most  

of semen.

 A gland that 

surrounds the urethra, which 

produces a fuid that is added to 

semen.

 Also called 

the bulbourethral glands, they 

add a small amount of fuid to 

the volume of semen.

 A chemical substance 

that is produced in one organ 

and carried through the 

bloodstream to afect another 

part of the body.

 A glandular 

system that produces hormones.

 A control 

mechanism by which a change 

sets off a response that 

increases the initial change.

 A control 

mechanism by which a change 

sets off a response that 

counteracts the initial change.

Gonadotropin-releasing 

Hormone (GnRH)

 Hypothalamic 

hormone that stimulates the 

pituitary gland to release 

luteinizing hormone (LH) and 

follicle-stimulating hormone 

(FSH).

 A 

pituitary hormone that causes 

the production and release of 

testosterone in males.

A part of the brain 

involved in hormone release, 

biological rhythms, emotions, and 

sex drive.

Also called the 

“master gland,” the pituitary gland 

produces hormones that control 

other glands and many bodily 

functions including growth, 

metabolism, and reproduction.

Maintenance of the 

body’s stable internal environment.

Produced by the 

testes and in small amounts by the 

ovaries, this hormone stimulates 

development of male sexual 

characteristics, bone and muscle 

growth, and libido.

A family of hormones 

that promote and maintain male 

physical characteristics.

Secondary Sexual Characteristics 

Traits (other than those that 

are part of the reproductive system) 

that distinguish males and females.

A pair of glands 

that sit atop the kidneys and 

produce androgens, as well as 

hormones that control metabo-

lism, fuid balance, and blood 

pressure.

A 

potent male hormone involved in 

prenatal development of the penis 

and scrotum.

One of the “female” 

hormones responsible for female 

sex characteristics, as well as 

reproductive, bone, and brain 

development in both sexes.

Also called 

androgen defciency in aging 

males (ADAM), andropause is a 

gradual decline in a man’s 

energy and sex drive caused by 

diminished levels of androgens 

that occur with aging.

The metabolic 

process of building tissue.

Related to the 

development or maintenance of 

masculine characteristics.

A type of lipid molecule 

with a multiple-ring structure.

The enzyme-containing

cap on the head of 

the sperm.

A component in 

the nucleus of the cell that 

contains genes.

A sequence of DNA that 

gives information for making 

proteins.

One of 22 pairs of 

non-sex chromosomes.

The X and Y 

chromosomes.

The production of 

sperm.

Spermatogonia

A stem cell that 

will become a sperm.

Primary Spermatocyte 

An 

immature male germ cell 

containing 46 chromosomes.

A 

male germ cell that has gone 

through its frst meiotic division.

The 

process of cell division in the 

egg and sperm.

An 

immature sperm cell with 23 

chromosomes.

Spermatozoa

A 

substance, produced by Sertoli 

cells, that binds testosterone.

Hypospadias

A congenital condition in 

which the urethra opens on the 

underside of the penis rather 

than at the end.

A downward curva-

ture of the penis, often 

associated with hypospadias.

Peyronie’s Disease 

Curvature of the penis 

caused by the growth of fbrous 

scar tissue.

A 

tight, nonretractable foreskin.

A prolonged and often painful 

erection.

A dilated vein in the spermatic 

cord.

Prostatitis

An infammation of the 

prostate gland, usually caused 

by bacteria.

Benign Prostatic Hyperplasia 

(BPH) 

An enlargement of the 

prostate gland, not related to 

infection or cancer.

Prostate Specifc Antigen 

(PSA) 

A protein produced by 

the prostate; PSA levels are 

elevated with prostate cancer 

and BPH.