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)
menopause
cessation of menses
decreased levels of estrogen
hot flashes
osteoporosis
atrophy of reproductive organs and breasts
irritability and sometimes depression
decreased levels of HDL
treated with small doses of estrogen/progesterone
structures associated w/ testes
tunica albuginea
tunica vaginalis
pampiniform venous plexous
where do sperm acquire their motility
epididymis
follicle cells are part of
primordial follciles
the uterus is anchored to the anterior body wall by the
round ligament
cryptorchidism
testes fail to descend
clitoris
counterpart of penis
labia majora
counterpart of male scrotum
follicular cells
granulosa cells
the cells that result from the equatorial division of spermatogenesis are called
spermatids
spermiation
the release of a sperm cell from its connection to a sertoli cell
zona pellucida
the glycoprotein layer b/w the oocyte and granulosa cell of an ovarian follicle
corona radiata
thick outer layer of ovarian follicle
theca interna
secretory cells of an ovarian follicle
theca externa
cells of an ovarian follicle that produce collagen
the perineum is bounded by
pubic symphysis
ischial tuberosities
coccyx
seminal fluid comp.
fructose
citric acid
coagulating enzyme
prostaglandins
prostate gland fluid comp.
citrate
enzymes
prostate specific antigen
seminal glands
posterior and inferior to bladder
estrogen
builds up endometrium
stimulates oxytocin receptors on the uterus
initiation of Braxton Hicks
fertilization
- sperm are capacitated
- sperm follow olfactory trail
- sperm goes through corona radiata then binds to zona pellucida (acrosomal rxn)
- enzymes released digest holes in zona pellucida
- 100s of acrosomes release enzymes to digest zona pellucida
- after fusion of plasma membrane of sperm and oocyte, Ca2+ is released triggering cortical rxn (cortical granules release ZIPs to destroy sperm receptors)-> prevents polyspermy
- Ca2+ surge also triggers completion of meiosis II and results in ovum + 2 more polar bodies
- sperm and ovum nucleus form male and female pronucleus
cleavage
mitotic divisions of zygote
at day 4 or 5, zygote becomes blastocyte (embryo)-> implants 6-7 days after ovulation-> converts to gastrula
blastocyte
composed of trophoblast and inner mass cells
hCG
triggers corpus luteum to continue to secrete progesterone and estrogen
levels decline after placenta secretes progesterone and estrogen instead
highest during 9th week of pregnancy
placentation
formation of placenta from embryonic and maternal tissues
inner cells mass
give rise to extraembryonic mesoderm that lines the surface of trophoblast
trophoblast
give rise to chorion and chronic villi (fetal portion of placenta)
release enzymes that digest endometrium
decidua baslis
maternal portion of placenta
stratum fucntionalis b/w chronic villi and stratum basale of endometrium
gastrulation
occurs wk 3
embryonic disc composed of ectoderm, mesoderm, and endoderm
appearance of primitive streak (establishes longitudinal axis of embryos)
conversion of embryo to gastrula
ectoderm
forms fetal NS and epidermis
endoderm
forms fetal epithelial linings and glands
mesoderm
forms fetal bones and muscles
parturition
- cortisol triggers placenta to release more estrogen
- production of oxytocin receptors by myometrium
- formation of gap junctions b/w uterine and smooth muscle cells
- antagonism of progesterone-> Braxton Hicks
- oxytocin triggers placenta to release prostaglandins-> more frequent and vigorous contractions
- oxytocin release from posterior pituitary triggers positive feedback on increasing size of cervix
- cervix effaces and dilates to 10 cm (dilation stage)
- amnion ruptures (dilation stage)
- engagement-> head enters true pelvis (dilation stage)
- crowning (expulsion stage)
- afterbirth-> delivery of placenta (placental stage)
lactation
production of milk by mammary glands
occurs towards end of pregnancy
placenta releases estrogen, progesterone, human placental lactogen->PRH via hypothalamus
AP releases prolactin
prolactin release decreases after birth
lactation triggered by suckling
colostrum
initial breast milk that is more nutrient rich, yellow in color, and rich in IgA antibodies
let-down reflex
release of milk from nipple
ductus venosus
bypasses liver
umbilical vein->ductus venosus->IVC
foramen ovale
opening in interatrial septum
bypass pulmonary circulation
ductus arteriosus
bypasses pulmonary circulation
pulmonary trunk-> ductus arteriosus->aorta
side effects of pregnancy
chadwick’s sign (vagina develops purplish hue)
breasts enlarge and areola darken
melasma
lordosis
weight gain
possibility of gestational diabetes
increased levels of PTH and vit. D
ribs flare and thorax widens
morning sickness
heartburn and constipation
increased urine production
incontinence
nasal edema and congestion
increased BV and CO (40%)
varicose veins
increased tidal volume
glucose sparing
hPL
aka human placental lactogen
maturation of breasts
fetal growth
glucose sparing in mother (reserving glucose for fetus)
syncytiotrophoblasts
fetal cells that digest uterine cells
produce enzymes that allow implantation to occur
inner cell mass
develops into embryonic disc
umbilical vein
remnant of ligamentum teres
umbilical arteries
median umbilical ligaments
epiblast cells
form amnion, mesoderm, endoderm, and ectoderm
hypoblast cells
form yolk sac and atlantois
yolk sac
forms part of digestive tube
source of earliest blood cells and blood vessels
atlantois
structural base for umbilical cord
becomes part of urinary bladder
morula
solid ball of cells formed around 4th day after fertilization
implantation
usually occurs in the posterior wall of the body or fundus of the uterus
embryonic period
first 2 months following fertilization
weeks 3-8 of pregnancy
major development of organ systems
weeks 8-20 of pregnancy
bone formation
