12.8 Key Terms

blood–testis barrier

tight junctions between Sertoli cells that prevent bloodborne pathogens from gaining access to later stages of spermatogenesis and prevent the potential for an autoimmune reaction to haploid sperm

bulbourethral glands

(also, Cowper’s glands) glands that secrete a lubricating mucus that cleans and lubricates the urethra prior to and during ejaculation

corpus cavernosum

either of two columns of erectile tissue in the penis that fill with blood during an erection

corpus luteum

transformed follicle after ovulation that secretes progesterone

corpus spongiosum

(plural = corpora cavernosa) column of erectile tissue in the penis that fills with blood during an erection and surrounds the penile urethra on the ventral portion of the penis

ductus deferens

(also, vas deferens) duct that transports sperm from the epididymis through the spermatic cord and into the ejaculatory duct; also referred as the vas deferens

ejaculatory duct

duct that connects the ampulla of the ductus deferens with the duct of the seminal vesicle at the prostatic urethra

epididymis

(plural = epididymides) coiled tubular structure in which sperm start to mature and are stored until ejaculation

gamete

haploid reproductive cell that contributes genetic material to form an offspring

glans penis

bulbous end of the penis that contains a large number of nerve endings

gonadotropin-releasing hormone (GnRH)

hormone released by the hypothalamus that regulates the production of follicle-stimulating hormone and luteinizing hormone from the pituitary gland

gonads

reproductive organs (testes and ovaries) that produce gametes and reproductive hormones

inguinal canal

opening in abdominal wall that connects the testes to the abdominal cavity

Leydig cells

cells between the seminiferous tubules of the testes that produce testosterone; a type of interstitial cell

Müllerian duct

duct system present in the embryo that will eventually form the internal female reproductive structures

penis

male organ of copulation

prepuce

(also, foreskin) flap of skin that forms a collar around, and thus protects and lubricates, the glans penis; also referred as the foreskin

prostate gland

doughnut-shaped gland at the base of the bladder surrounding the urethra and contributing fluid to semen during ejaculation

puberty

life stage during which a male or female adolescent becomes anatomically and physiologically capable of reproduction

scrotum

external pouch of skin and muscle that houses the testes

secondary sex characteristics

physical characteristics that are influenced by sex steroid hormones and have supporting roles in reproductive function

semen

ejaculatory fluid composed of sperm and secretions from the seminal vesicles, prostate, and bulbourethral glands

seminal vesicle

gland that produces seminal fluid, which contributes to semen

seminiferous tubules

tube structures within the testes where spermatogenesis occurs

Sertoli cells

cells that support germ cells through the process of spermatogenesis; a type of sustentacular cell

sperm

(also, spermatozoon) male gamete

spermatic cord

bundle of nerves and blood vessels that supplies the testes; contains ductus deferens

spermatid

immature sperm cells produced by meiosis II of secondary spermatocytes

spermatocyte

cell that results from the division of spermatogonium and undergoes meiosis I and meiosis II to form spermatids

spermatogenesis

formation of new sperm, occurs in the seminiferous tubules of the testes

spermatogonia

(singular = spermatogonium) diploid precursor cells that become sperm

spermiogenesis

transformation of spermatids to spermatozoa during spermatogenesis

testes

(singular = testis) male gonads

Wolffian duct

duct system present in the embryo that will eventually form the internal male reproductive structures