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what are the main hormones?
estrogen, FSH, LH and progesterone
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what is the main active hormone of estrogen?
estradiol
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what is the major sex organ and sex cells?
ovaries produces gamates (eggs or ova)
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what are the accessroy reproductive ducts?
- uterine tubes
- uterus
- vagina
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what are the layers of the ovary
tunica albuginea and germinal epithelium, outer cortex (form gametes), inner medulla (large blood vessels and nerves
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what is an ovarian follicle and where is it embedded in?
- cortex, made up of immature egg (oocyte and surrounded by follicle cells)
- granulosa cells have more than one layer of follicle
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why is the fibrous layer of the ovary not that thick?
egg needs to be ovulated
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what is the external covering of the uterine tubes?
peritoneum
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what is the distal expansion near ovary ends in ciliated fimbriae called?
infundibulum, helps find ovulated egg
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what is the role of the cervical glands?
secrete muscus that blocks sperm entry except during midcycle
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what is the superior part of the uterus called?
fundus
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what is the internal os
body of uterus opens to isthmus
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what is the external os
opening to the cervical canal on the external side
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what are the three layers of the uterine wall?
- endometrium (stratum functionalis and stratum basalis)
- myometrium
- perimetrium
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how does the uterine vascular supply branch?
- uterine arteries branch into arcuate artersies in the myometrium
- arcuates branch into radial (goes through perimetrium and the myometrium)
- radial goes to straight (stratum basalis) or spirl arteries (stratum functionalis)
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what is the fornix
ring at the base of the cervix
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what are the layers of the vagina wall?
- mucosa (stratified)-secretes mucous which has glycogen (acidic)
- muscularis (smooth muscle)
- advantitia (fibroelastic)
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what is the hymen?
mucosa near the vaginal orifice forms incomplete partition
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what are the stem cells of oogenesis called?
oogonia (2n overian stem cells)
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describe oogenesis
- before birth oogonia multiply by mitois and store nutrients
- primary oocytes develop in primordial follicles, begin meiosis but stall in prophase II
- one primary oocyte is selected each month to resume meiosis I
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what are the two haploid cells created after meiosis of the selected primary oocyte?
secondary oocyte and first polar body
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what occurs to the secondary oocyte?
- arrests in metaphase II; then ovulated
- if not penetrated by sperm, it deteriorates
- if penetrated by sperm, secondary oocyte completes meiosis II, yield ovum and scond polar body
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what are the phases of the ovarian cycle?
- follicular phase (can change in number)
- ovulation (in midcycle)
- luteal phase (corpus luteum activity-number of days remains constant)
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what helps granulosa cells and oocyte guide one another's development?
gap junctions
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name the progression of the egg in the follicular phase
primordial follicle becomes primary follicle becomes secondary follicle (granulosa cells), which become late secondary follicle, which becomes tertiary follicle
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what happens in the late secondary follicle?
- connective tissue (theca folliculi) and granulose cells produce estrogens
- inner theca cells produce androgens in response to LH
- zona pellucida forms
- fluid accumulates in granulose cells
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how are estrogen produced?
FSH stimulates ovary to release estrogen (directly) or theca cells produced androgens which produce estrogen (indirectly)
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what are zona pellucide
- where gap junctions are located, between the oocyte and follicle cells
- has microvilli (increase SA) very easy to move nutrients between egg and follicle cells
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what happens in the tertiary follicle?
- antrum forms; expands to isolate oocyte with corona radiata
- tertiary follicle bulges from external surface of ovary (which blocks blood supply to thin wall, cells die, which will allow follicles to burst out on the side
- primary oocyte completes meiosis I producing secondary oocyte and first polar body
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what is the corona raidata
follicles still around the egg as the antrum expands isolating the egg
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what happens in the ovulation phase?
tertiary follicle bursts and ovary wall ruptures, expels secondary oocyte with its corona radiata to pelvic cavity
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how does one get fraternal twins? identical twins?
- more than one secondary oocyte is ovulated
- single ovulation, which causes the egg to be fertilized and then the egg divides
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what happens int he luteal phase?
- ruptured follicle collapses, antrum fills with clotted blood
- granulosa cells and internal theca cells form corpus luteum
- no pregnancy, corpus luteum degenerates into corpus albicans in 10 days
- pregnancy: corpus luteum producese hormones that sustain pregnacy until placenta
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what does the LH spike at midcycle cause?
- causes ovulation
- -triggers inflammatory response, weakens ovarian wall
- blood flow stops through protruding follicle wall: wall things, bulges and ruptures
- ovulation happens
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what happens after ovulation?e
- estrogen levels delcine
- LH transforms ruptured follicle (corpus luteum) which releases progesterone and some estrogen
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what is the role of corpus luteum
- makes progesterone and feeds back to prevent ovary from ovulating another egg
- LH regulates corpus luteum
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what happens when progestrone levels decrease?
remove feedback on FSH and LJ, increase hormone again
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what is the role of LH?
regulates corpus luteum and stimilates the theca and granulose cells that produce androgens
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what happens at low levels of estrogen and high levels of estrogen?
- low levels (prevent LH secretion)
- high levels: creates huge spike in LH secretion: triggers ovulation
- LH sells, constricts blood flow, causes ouvlation and corpus leuteum to produce progesterone
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what happens to the corpus luteum when no fertilization occurs?
- corpus luteum degenerates when LH levels fall, creates sharp decrease in estrogen and progesterone, ends blockage of FSH and LH secretion
- cycle starts
- oocyte is activated 12 months prior to ovulation
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when does the uterine cycle begin and end?
first cycle at menarche (begins at puberty), cycle continues until menopause
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what is the function of the uterine cycle?
prepare uterine lining for implantation of fertilized ovum, called zygote
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what are the three phases of the uterine cycle?
- menstrul phase
- proliferative (preovulatory phase)
- secretory (postovulatory) phase (constant 14 days)
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what happens in the menstrul phase?
- ovarian hormones at lowest levels (GnRH) begins to rise
- functional zone of endometrium sheds as a result of constrictuion of arteries
- by day 5, growing ovarian follicles produce more estrogen
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what happens in the proliferative phase?
- rising estrogen levels promt generation of new statum functionalis layer, increased synthesis of pregesterone receptors in endometrium, glands enlarge and spirl arteries increase in number
- cervical mucus thins due to rise in estrogen (allows sperm passage)
- ovulation at end of proliferative phase
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what happens in the secretory phase?
- begins at ovulation
- endometrium prepares for embryo
- rising progesterone levels
- if fertilization does not occur, corupus luteum degenerates toward end of secretory phase (progesterone levels fall) endometrial cells begin to die; glands regress, menses begins again
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