reproductive system Flashcards
primary male sex organs
testes (produce sperm and testosterone)
secondary male sex organs
epididymis (sperm storage, nutrient transfer to stored sperm, absorption of testicular fluid)
ductus deferens (vas deferens)-> transports sperm from epididymis to urethra
seminal vesicles (produces alkaline seminal fluid)-> majority of semen
prostate (secretes acidic fluid, sperm activation, transportation and production of sperm)
bulbo-urethral glands (cowper’s glands)-> produces mucous during arousal, lubricates, neutralizes acidic urine)
GnRH
indirectly stimulates testes via FSH and LH
testosterone
directly stimulated by FSH and LH
neg feedback on hypothalamus and AP
inhibin
inhibits GnRH and FSH release
neg feedback on hypothalamus and AP
spermatogenesis
mitosis of spermatogonia forms 2 primary spermatocytes (2n)
meiosis transforms primary spermatocytes to secondary spermatocytes (n)-> 4 round spermatids
round spermatids become spermatozoa via elongation (lose excess cytoplasm and form a tail)
sertoli cells
aka sustentacular cells
provide nutrients and signals for sperm transport, phagocytize faulty germ cells and excess cytoplasm
produce chemical mediators to regulate spermatogenesis
target cell of FSH
produce androgen-binding protein
leydig cells
primary source of testosterone
aka interstitial cells
are located in spaces b/w adjacent seminiferous tubules of testis
target cell of LH
anatomy of sperm
acrosome (enable sperm to penetrate egg)
flagella (provides motility)
midpiece (produces ATP to move tail)
comp. of semen
prostaglandins (decrease viscosity)
relaxin (provides sperm motility)
ATP (provides energy)
semen
alkaline white mixture of sperm and accessory gland secretions
erection
NO release triggers smooth muscle relaxation
arterioles dilate and corpora cavernosa expands
erectile tissue fills w/ blood
penis enlarges and stiffens
ejaculation
bladder constricts
ducts and accessory glands contract
bulbospongiosus muscles rapidly contract in a series (orgasm)
pathway of sperm
seminiferous tubules-> epididymis->ductus deferens-> ejaculatory duct->urethra-> glans penis
meiosis 1
random alignment of homologous pairs (synapsis)-> formation of tetrads
crossover (chiasmata)-> exchange of genetic material b/w male and female chromatids
primary spermatocyte (2n)-> two secondary spermatocytes (n)-> 2 genetically diff. daughter cells
meiosis 2
secondary spermatocyte (n)-> 4 spermatids (n)-> 4 genetically diff daughter cells
blood testis barrier
prevents activation of immune system of the male against developing sperm
type A cells
maintain germ cell line at basal lamina
type B cells
move towards lumen and develop into primary spermatocytes
mitosis of spermatogonia
results in one type A and one type B daughter cell
basal compartment of tight junction
spermatogonia and primary spermatocytes
adluminal compartment of tight junction
meiotically active cells and tubule lumen
dartos muscle
wrinkles scrotal skin
cremaster muscle
elevates testes
primary female sex organs
ovaries= produce ova, estrogen, and progesterone
secondary female sex organs
fallopian tubes= transport ova out of ovary
uterus= ovum implantation and development into fetus site
vagina= birth canal
vulva= sexual arousal and protection
GnRH
triggers the release of FSH and LH
theca cells
in response to LH, produce androgens
granulosa cells
in response to FSH, convert androgens to estrogen
secrete progesterone after ovulation to maintain corpus luteum (increased estrogen and progesterone levels)
LH
increase estrogen levels
triggers ovulation
FSH
triggers the growth of eggs in the ovaries and preps them for ovulation
initiates spermatogenesis in males
oogenesis
oogonia (2n) multiply via mitosis and store nutrients during fetal period
primary oocytes develop in primordial follicles (prophase 1)
during ovulation, 2 haploid cells (secondary oocyte and first polar body) result via meiosis 1
pauses at metaphase 2 and completes meiosis 2 if fertilized (results in ovum and 2 more polar bodies)
if not fertilized, deteriorates
after puberty, primordial follicles mature into primary follicles, which mature into secondary follicles, and then mature into graafian follicles before ovulation every month until menopause
follicular phase
increase FSH levels
primary follicle->secondary follicle->graafian follicle
increase estrogen levels
increase LH levels
decrease progesterone levels
luteal phase
ruptured follicle turns into corpus luteum
increase progesterone levels
increase estrogen levels
if fertilized, corpus luteum is maintained and progesterone production continues
if not fertilized, corpus luteum degenerates (decrease progesterone levels, decrease estrogen levels, breakdown of endometrium= menstruation)
ovulation
decreased LH levels
decreased FSH levels
follicle ruptures=egg released
increased progesterone levels
decreased estrogen levels
uterine cycle
menstrual phase= hormones levels decrease, bleeding (days 1-5)
proliferative phase= levels of estrogen increase, ovulation, egg-white like cervical mucous (days 6-14)
secretory phase= levels of progesterone increase, cervical mucous thickens, corpus luteum-> corpus albicans (days 15-28)