[Exam 4] chapter 27 Flashcards
scrotum
sac of skin & superficial fascia; contains paired testes separated by a midline septum that provides a compartment for each testis
- external positioning keeps testes 3°C lower than core body temp. (necessary for sperm production)
testes
(within scrotum) produce sperm; septa divide testis into approx. 250 lobules, each containing 1-4 seminiferous tubules
seminiferous tubules
thick, stratified epithelium surrounding central fluid-containing lumen; produce sperm; converge to form straight tubule
straight tubule
conveys sperm to rete testis
rete testis
where sperm partially mature
efferent ductules
route from the rete testis to the epididymis; parallel thin, delicate tubules
epididymis
hugs external testis surface posteriorly; made up of head, body & tail; sperm is stored in tail until ejaculation
interstitial cells
(leydig cells) that produce androgens (mostly testosterone)
testicular cancer
rare (only affects 1 of every 50,000 males); most common in males 15-35 y.o.
-risk factors= cryptorchidism (nondescent of testes) [most important]; mumps ➡orchitis (inflammation); mom’s exposure to toxins before birth; 90% cured by surgical removal of cancerous testis (orchiectomy)
spermatic cord
encloses parasympathetic nervous system & sympathetic nervous system nerve fibers, blood vessels, lymphatic vessels, & ductus deferens that supply testes
- passes through inguinal canal
penis
male copulatory organ designed to deliver sperm into female reproductive tract; apart of external genitalia
-consists of root & shaft that ends in glans penis
glans penis
rounded head / tip of penis; opening of urethra located in middle
erectile tissue
spongy network of connective tissue & smooth muscle riddled w/ vascular spaces
ductus / vas deferens
approx. 18 in long; passes through inguinal canal to pelvic cavity (part of spermatic cord); expands to form ampulla; joins duct of seminal vesicle to form ejaculatory duct; smooth muscle in walls propels sperm from epididymis ➡ urethra
ejaculatory duct
each duct enters prostate; propels sperm from ductus deferens to urethra
prostatic urethra
conveys urine & semen at different times; surrounded by prostate
intermediate / membranous urethra
lies in between prostate & bulb of penis
spongy / penile urethra
runs through penis & opens to the outside at the external urethral orifice
- contains urethral glands that secrete mucus into lumen just before ejaculation
vasectomy
cutting & ligating (ties off) ductus deferens; nearly 100% effective form of birth control; reverse rate is approx. 50%
peristalsis
involuntary constriction and relaxation of seminiferous tubules creating wave-like movements that push sperm into epididymis
seminal vesicles / glands
male accessory gland; on posterior bladder surface; smooth muscle contracts during ejaculation
- produces viscous alkaline seminal fluid containing: fructose, coagulating enzyme (fibrinogen) & prostaglandins
- 60-70% volume of semen
prostate gland
male accessory gland; produces 20-30% of semen; single gland; consists of smooth muscle that contracts during ejaculation; enters prostatic urethra during ejaculation
bulbourethral glands
male accessory gland; pea-sized & inferior to prostate
- produce thick, clear mucus prior to ejaculation
- neutralizes traces of acidic urine in urethra
- lubricates glans penis
- neutralizes vagina
semen
milky-white mixture of sperm, testicular fluid & accessory gland secretions; only 2-5 ml of semen ejaculated; contains 20-150 million sperm/ml
-relative alkalinity (pH 7.2-8.0) neutralizes acid environment in male urethra & enhances motility
function of fructose in semen
ATP production; protects & activates sperm; facilitates sperm movement
function of prostaglandins in semen
decrease viscosity of mucus in cervix; stimulate reverse peristalsis in the uterus
- help facilitate movement of sperm through female reproductive tract
- contains clotting factors (fibrinogen) to coagulate semen immediately after ejaculation to prevent draining out; also liquifies semen
erection
enlargement & stiffening of the penis from engorgement of erectile tissue w/ blood
- parasympathetic nervous reflex promotes release of nitric oxide (NO) locally ➡ erectile tissue to fill w/ blood
- corpus cavernosa compresses drainage veins & retards blood outflow to maintain engorgement
- longitudinal & circular collagen fibers prevent buckling of erect penis