Module 28: Male Reproductive System

testes

male gonads

scrotum

the supporting structure for the testes, consists of loose skin and underlying subcutaneous layer.

cremaster muscle

a series of small bands of skeletal muscle that descend as an extension of the internal oblique muscle through the spermatic cord to surround the testes.

dartos muscle

subcutaneous smooth muscle of the scrotum.

seminiferous tubules

A tightly coiled duct, located in the testis, where sperm are produced.

spermatogenesis

The formation and development of sperm in the seminiferous tubules of the testes.

sustentacular cells

A supporting cell in the seminiferous tubules that nourishes, supports, prepares, releases sperm and forms the blood-testis barrier.

Also called a Sertoli cell.

spermatogonia

stem cells in the seminiferous tubules that undergo mitosis or differentiate and become primary spermatocytes that enter meiosis.

secondary spermatocyte

spermatogenic cells formed after meiosis I that enter meiosis II.

Interstitial cells

A type of cell that secretes testosterone; located between seminiferous tubules. Also known as a Leydig cell.

spermatids

The four haploid cells resulting from meiosis II but prior to spermiogenesis.

spermiogenesis

The maturation of spermatids into sperm.

epididymis

site of sperm maturation - the process by which sperm acquire motility and the ability to fertilize.

vas deferens

The duct that carries sperm from the epididymis to the ejaculatory duct.

inguinal canal

A passageway in the anterior abdominal wall between the abdominopelvic cavity and scrotum.

spermatic cord

A supporting structure of the male reproductive system, extending from a testis to the inguinal canal that contains the vas deferens, arteries, veins, lymphatic vessels, nerves, and cremaster muscle.

corpus spongiosum

erectile tissue that surrounds the urethra - keeps urethra open during ejaculation.

corpora cavernosa

two cylindrical masses of erectile tissue.

ejaculatory duct

tubes that transport sperm from the vas deferens to the prostatic urethra.

seminal vesicles

glands that secrete an alkaline, viscous fluid that contains fructose (a monosaccharide sugar), prostaglandins, and clotting proteins that are different from those in blood.

prostate gland

gland that secretes a milky, slightly acidic fluid that contains several substances that promote viability and motility of sperm.

bulbourethral (Cowper's) glands

glands that secrete an alkaline mucus that neutralizes acidity and lubricates the end of the penis and the lining of the urethra.

glans penis

The slightly enlarged region at the distal end of the penis.

prepuce

foreskin surrounding the glans penis.

luteinizing hormone (LH)

hormone produced by anterior pituitary that stimulates testosterone secretion by Leydig cells.

follicle-stimulating hormone (FSH)

hormone secreted by the anterior pituitary initiates sperm production in males.

testosterone

hormone secreted by Leydig cells needed for development of sperm; together with a second androgen termed dihydrotestosterone (DHT), controls the growth and development of male reproductive organs, secondary sex characteristics, and body growth.

acrosome

An organelle in the head of a sperm cell containing enzymes that facilitate the penetration of a sperm cell into a secondary oocyte.

middle piece

structure of sperm that contains mitochondria arranged in a spiral, which provide the energy (ATP) for locomotion of sperm