male reproductive system
Card Set Information
male reproductive system
where is the dartos muscle contained?
in the superficial fascia of the scrotum
what are the layers that surrounds the testes?
tunica vaginalis (outer layer from peritoneum)
tunica albugnea (inner, dense fibrous capsule that folds in to divide testis
where does the testicular arteries arise from?
what is the purpose of the pampiniform venous plexus?
testicular veins arise from
surrounds each testicular artery to cool artery going to the testes
how does the teste migrate to the scrotum during fetal development?
from abdominal to inguinal canal (development as ligament that gets pulled down)
what is the condition where there is an abnoraml descent of the testes?
what may happen to a male's fertilitiy is cryptorchidism is not corrected?
sperm can't be produced b/c the temperature is too warm.
: outside the ouside layer (tunica vaginalis)
where does sperm production occur?
in the seminiferous tubles; thick, stratified epithelium surrounding central fluid-containing lumen
what kind of cells squeeze sperm, testicular fluids out of testes?
what kind of cells does the seminiferous tubles contain?
nurse cells that support spermatogenesis
interstitial endocrine cells that produce androgens (secrete hormones)
what is the progression of the sperm cells?
spermatocytes to spermatids to spermatozoa
what is spermatogenesis?
production of sperm in the seminiferous tubles
begins at puberty
each division produces a daughter cell that is pushed toward the lumen of the tuble
what occurs in spermatogenesis?
spermatogonia (stem cells) in contact with epithelial basal lamina
each mitotic division yields one type A and one type B daughter cell (primary spermatocyte)
meiosis I and II
what happens in meiosis I?
primary spermatocyte (2n) goes to form secondary spermatocyte (n)
what happens in meiosis II
secondary spermatocyte (n) forms two spermatids (small, nonmotile cells close to lumen of the tuble
what is spermiogenesis?
final stage in sperm production
spermatids elongate; lose excess cytoplasm, form a tail, become spermatozoon
what are the parts of a sperm?
head (genetic region) nucleus and helmet like acrosome (contains hydrolytic enzymes that enable sperm to penetrate egg)
: metabolic region; mitochondra which gives ATP to move tail
how is the blood testis barrier formed?
tight junctions divide tubule into two compartments, prevent sperm from getting into the blood
what is the role of the nurse cells?
provide nutrients and signals to dividing cells
move cells along to lumen
secrete testicular fluid into lumen for sperm transport
phagocytize germ cells and excess cytoplasm
make sure sperms don't get out of the testes and into blood (body would amount immune response otherwise)
what is the movement of the sperm after seminiferous tubules
straight tubule then the rete testis then the efferent ductules then epididymis
what is the epididymis?
where sperm is stored, the beginning of the male reproductive tract
supply nutrients to the spermatoza
takes two weeks for the sperm to travel through, after which they are physically mature (learned to swim)
ajusts fluid produced by seminiferous tubules with microvilli
contracts to produce ejaculation, expelling sperm to ductus deferens
what happens at the duct of the epididymis
micorvilli absorb testicular fluid (establish concentration inside tubule) and pass nutrients to stored sperm
how does the sperm migrate after the epididymis?
ductus deferens, ejaculatory duct, urethra
how does the ejaculatory duct form?
vas deferens passes through inguinal canal to pelvic cavity, which joins duct of seminal vesicle
what conveys both urine and semen through the prostate gland and the penis?
what are the accessory glands?
what is the function of the seminal glands?
contributes 60-70% of the semen fluid
constricts like vas deferens and epididymis to ensure fluid gets into uretha as well
prostaglandins stimulate smooth muscle to help sperm move up the reproductive tract
fibrinogen forms semen clot in vagina
slightly alkalin to buffer acid environments
provide fluid that initiates capacitation (development of motility)
what is the role of the prostate gland?
secretes milky, slightly acidic fluid (20-30% of semen volume)
: antibiotic properties, appears to help prevent UTIs
what happens in ejaculation?
sperm is forced up into the vas deferens, which goes up, around the front of, over the top of, and behind the bladder
what will happen when the prostate gland enlarges?
interferes with urination by constricting the urethra
what is the function of the bulbo-urethral glands?
produce thick, clear mucus during sexual arousal to lubricate penis and neutralize traces of acidic urine in uretha
what are the three regions of the penis?
root (bulbo-urethral gland)
what does the cylindrical bodies of the erectile tissue consists of?
spongy network of connetive tissue and smooth muscle with vascular spaces
where does the erectile tissues arise?
: surrounds urethra and expands to form glans and bulbs
: paired dorsal erectile bodies
what happens in the penis during resting state?
arterial branches of corpus spongiosum constricted, little blood flow
what happens in the penis during an erection?
parasympathetic neurons release NO, a vasodilator
causes vascular smooth muslce relaxation
arterioles dilate, corpora cavernose expand, blocks venous drainage
engorgment of erectile tissues with blood (enlargement and stiffening of the penis)
what happens in ejaculation?
a sympathetic spinal reflex where ducts, bulbospongiosus muscles and accessory glands contract and empoty their contents
bladder sphincter muscle constricts, preventing expulsion of urine
what are the causes of erectile dysfunction?
too little NO from parasympathetic stimulation (alcohols, drugs)
incompetent venous valves
what is the HPG axis?
regulates production of gametes and sex hormones through 3 interacting sets of hormones
GnRH indirectly stimulates testes via FSH and LH
FSH and LH direcly stimulates testes
what is the role of FSH in males?
targets nurse cells to trigger spermatogenesis
what is the role of LH in males?
causes interstitial cells to secrete testosterone
testosterone and inhibin (negative feedback on hypothalamus and anterior pituitary)