Male Reproductive Anatomy, Physiology, and Sexual Response

Comprehensive vocabulary flashcards covering the male reproductive duct system, accessory glands, and the three phases of the male sexual response.

Myoid cells

Muscle-like cells located within the seminiferous tubules that contract to squeeze and propel sperm through the duct system.

Epididymis

A comma-shaped structure surrounding the testis where sperm mature for about $20$ days and can be stored in the tail for several months.

Ductus deferens

Also known as the vas deferens, this duct contains a smooth muscle layer called the muscularis that contracts to propel sperm during ejaculation.

Vasectomy

A contraceptive medical procedure where each ductus deferens is tied off and cut to create a permanent break in the passage of sperm.

Ejaculatory duct

The structure formed by the fusion of the ductus deferens and the duct of the seminal vesicle.

Urethra segments (Male)

The three parts of the male urethra are the prostatic urethra (through the prostate), the membranous urethra (through the urogenital diaphragm), and the spongy urethra (through the penis).

Seminal fluid

An alkaline fluid produced by accessory glands that neutralizes vaginal acidity and provides nutrients like fructose to nourish sperm.

Seminal vesicles

Glands on the posterior bladder that produce $70\%$ of seminal fluid volume, containing fructose for energy and prostaglandins to thin cervical mucus.

Prostate gland

A walnut-sized gland that contributes $30\%$ of seminal fluid volume, containing citric acid, seminalplasmin, and prostate-specific antigen (PSA).

Seminalplasmin

A natural antibiotic contained in prostatic fluid that helps prevent urinary tract infections in males.

PSA (Prostate-specific antigen)

An enzyme produced by the prostate gland that liquefies semen following ejaculation.

Bulbourethral glands

Also known as Cowper's glands, these pea-sized glands produce thick, clear mucus to neutralize traces of acidic urine in the urethra and provide lubrication.

Semen

Also called ejaculate, this is the combination of sperm and seminal fluid; $2-5\,ml$ typically contains $200-500$ million sperm.

Corpus spongiosum

A ventral erectile body surrounding the spongy urethra that functions to keep the urethra open during the male sexual response.

Corpora cavernosa

Paired dorsal and lateral erectile bodies containing cavernous spaces that fill with blood to cause an erection.

Excitement phase

The first phase of the male sexual response where parasympathetic stimulation causes the release of nitric oxide, leading to vasodilation and erection.

Ejaculation/Orgasm phase

The second phase of the male sexual response where the sympathetic division causes the internal urethral sphincter to close and propels semen out at approximately $11\,\text{miles per hour}$.

Relaxation phase

The final phase where the sympathetic division causes vasoconstriction of arterioles and muscle contraction to squeeze blood out of erectile bodies, returning the penis to a flaccid state.

Refractory period

A time period following the relaxation phase, ranging from minutes to hours, during which a male cannot enter an erect state again.