The Male Reproductive System

Vocabulary flashcards covering the anatomy, physiology, and hormonal regulation of the male reproductive system based on lecture notes.

Scrotum

A supporting structure for the testes, internally divided into two pouches by a septum composed of superficial fascia and dartos muscle.

Dartos

A bundle of smooth muscle within the scrotal septum.

Cremaster muscle

A muscle that regulates the temperature of the testes by elevating them in response to cold or sexual arousal and depressing them for heat.

Tunica vaginalis

A serous membrane surrounding the testes that is derived from the peritoneum.

Tunica albuginea

A membrane deep to the tunica vaginalis that forms septa and divides the testes into lobules.

Seminiferous tubules

Coiled tubules located within the lobules of the testes which serve as the site for sperm production.

Spermatogonia

Spermatogenic cells located next to the basement membrane of the seminiferous tubule that undergo spermatogenesis (meiosis) and mitosis.

Sertoli cells

Cells extending from the basement membrane to the lumen that support, protect, and nourish developing spermatogenic cells and secrete fluid for sperm transport.

Testosterone

A hormone responsible for the development, growth, and maintenance of male sex organs, final maturation of sperm, and the descent of testes during embryogenesis.

Follicle stimulating hormone (FSH)

A hormone that acts on Sertoli cells to stimulate spermatogenesis.

Inhibin

A substance secreted by Sertoli cells that regulates sperm production by inhibiting the secretion of FSH.

Leydig cells

Cells located between the seminiferous tubules that secrete testosterone and are regulated by interstitial cell-stimulating hormone.

Acrosome

A modified secretory vesicle/lysosome in the sperm head filled with enzymes like hyaluronidase and proteinases.

Midpiece

The portion of a spermatozoan containing many mitochondria for energy production.

Straight tubules

Ducts that connect the seminiferous tubules with the rete testis.

Rete testis

A network of tubules connecting the straight tubules to the epididymis.

Epididymis

A comma shaped organ where sperm maturation occurs over $10-14$ days, as well as sperm storage and reabsorption.

Ductus (Vas) deferens

A larger diameter duct that transports sperm from the epididymis to the urethra and serves as a site for sperm storage and reabsorption.

Ampulla

The dilated terminal portion of the vas deferens before it joins the seminal vesicle duct.

Spermatic cord

A supporting structure consisting of the vas deferens, blood and lymphatic vessels, nerves, cremaster muscle, and connective tissue.

Ejaculatory ducts

Ducts formed by the union of the seminal vesicle duct and the vas deferens that eject spermatozoan and secretions into the urethra.

Prostatic urethra

The portion of the urethra that passes through the prostate gland.

Membranous urethra

The portion of the urethra that passes through the urogenital diaphragm.

Spongy (penile) urethra

The portion of the urethra that passes through the corpus spongiosum of the penis and ends at the external urethral orifice.

Semenogelin

A fibrinogen derivative in seminal vesicle secretions responsible for the coagulation of semen following ejaculation.

Prostate gland

An accessory gland that secretes a slightly acidic fluid ($pH \text{ } 6.5$) containing citric acid, clotting enzymes, and fibrinolysin.

Fibrinolysin

An enzyme in prostatic secretion that de-coagulates semenogelin $5-20$ minutes after ejaculation to allow sperm motility.

Bulbourethral (Cowper’s) gland

A gland that secretes alkaline mucus to lubricate the lumen of the urethra.

Seminalplasmin

An antibiotic found in semen that may protect sperm from bacteria in the reproductive tracts.

Corpora cavernosa penis

Paired cylindrical tissue masses on the dorsolateral portion of the penis body.

Corpus spongiosum penis

The midventral mass of tissue in the penis containing the spongy urethra.

Glans penis

The distal end of the corpus spongiosum containing the external urethral orifice.