Male Reproductive System

testes

the male gonads

left

which male testicle is usually lower?

3 degrees C lower than body temperature (94F)

what is the ideal temperature for producing and storing sperm?

scrotum

a skin-covered sac between the thighs that provides the cooler environment for the testes

scrotal septum

a fibrous sheet that divides the scrotum that helps limit trauma or infection to one testis

labia majora

what female part is homologous to the scrotum?

perineal raphe

the ridgelike seam at the midline that runs from the inferior surface of the penis to the anus

dartos muscle

a layer of smooth muscle immediately internal to the fascia of the scrotum that helps regulate temperature by relaxing when exposed to elevated temperatures

cremaster muscle

a continuation of the internal oblique that also relaxes to allow the testes to move away from the body; also the middle layer of the spermatic cords

spermatic cord

a multilayered structure that connects the scrotum to the abdomen and contains blood vessels and nerves

internal spermatic fascia

the innermost layer of the spermatic cords that is formed from fascia deep to the abdominal muscles

external spermatic fascia

the outermost layer of the spermatic cords that is formed from the aponeurosis of the external oblique muscles

testicular artery

a singular vessel inside of the spermatic cord that is a direct branch of the abdominal aorta

pampiniform plexus

a plexus of veins that surround the testicular artery to provide a cooling system for the blood entering the testes

varicocele

an abnormal enlargement of the pampiniform plexus due to defective one way valves or if venous drainage is impaired; bag of worms

left; the left testicular vein connects to left renal vein, and right testicular vein connects directly to inferior vena cava; there is a problem when the superior mesenteric artery compresses the left renal vein

in which teste do varicoceles happen more often?

tunica vaginalis

the serous membrane that surrounds each teste; it is derived from the peritoneum

lobules

sections of division in the testes

seminiferous tubules

the highly coiled, elongated tubes in the lobules of the testes that produce sperm

• sustentacular cells

• germ cells

• interstitial cells

what types of cells are located in the seminiferous tubules?

sustentacular cells

a group of nondividing support cells that assist with sperm development by providing a protected environment and their cytoplasm helps nourish the sperm, they create the blood-testis barrier

blood testis barrier

the barrier formed by the cytoplasm of sustentacular cells in the testis that prevents the body’s leukocytes from attacking the sperm

interstitial cells

cells between the seminiferous tubules that produce the male hormones (androgens)

inferior vena cava

where does the right testicular vein drain to?

left renal vein

where does the left testicular vein drain to?

orchitis

inflammation of the testes; can occur in cases of the “mumps”

rete testis

a meshwork of interconnected channels that receive sperm from the seminiferous tubules

efferent ductules

the interconnected channels that are lined with cilia that propel the sperm from the rete testis to the epididymis

epididymis

the structure that sits on top of the testes and stores sperm until they are mature and ejaculated

duct of the epididymis

the long portion of the epididymis that contains stereocilia which are responsible for reabsorbing fluid which creates a current to move sperm along

ductus deferens (vas deferens)

the long tube-like structures that transport the sperm from the epididymis to the ejaculatory duct

once they are ejaculated

when do sperm exhibit full motility?

ampulla of the ductus deferens

the enlarged portion of the ductus deferens that widens and unites with the seminal vesicles to form the ejaculatory duct

ejaculatory duct

the long tube that is the connections of the ductus deferens and seminal vesicles where the semen travels down to the urethra

urethra

the tube in the penis that transports semen to the outside of the body

prostatic urethra

the region of the male urethra that extends through the prostate gland

membranous urethra

the region of the male urethra that travels through the muscles of the pelvic floor

spongy urethra

the region of the male urethra that extends through the penis

seminal fluid

a slightly alkaline fluid that is secreted by the seminal vesicles

• fructose - nourish sperm

• prostaglandins - promotes widening of cervix

• bicarbonate - keeps it alkaline to balance the acidity of the vagina

what is seminal fluid made of?