what are the main hormones?
estrogen, FSH, LH and progesterone
what is the main active hormone of estrogen?
what is the major sex organ and sex cells?
ovaries produces gamates (eggs or ova)
what are the accessroy reproductive ducts?
- uterine tubes
what are the layers of the ovary
tunica albuginea and germinal epithelium, outer cortex (form gametes), inner medulla (large blood vessels and nerves
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
why is the fibrous layer of the ovary not that thick?
egg needs to be ovulated
what is the external covering of the uterine tubes?
what is the distal expansion near ovary ends in ciliated fimbriae called?
infundibulum, helps find ovulated egg
what is the role of the cervical glands?
secrete muscus that blocks sperm entry except during midcycle
what is the superior part of the uterus called?
what is the internal os
body of uterus opens to isthmus
what is the external os
opening to the cervical canal on the external side
what are the three layers of the uterine wall?
- endometrium (stratum functionalis and stratum basalis)
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)
what is the fornix
ring at the base of the cervix
what are the layers of the vagina wall?
- mucosa (stratified)-secretes mucous which has glycogen (acidic)
- muscularis (smooth muscle)
- advantitia (fibroelastic)
what is the hymen?
mucosa near the vaginal orifice forms incomplete partition
what are the stem cells of oogenesis called?
oogonia (2n overian stem cells)
- 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
what are the two haploid cells created after meiosis of the selected primary oocyte?
secondary oocyte and first polar body
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
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)
what helps granulosa cells and oocyte guide one another's development?
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
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
how are estrogen produced?
FSH stimulates ovary to release estrogen (directly) or theca cells produced androgens which produce estrogen (indirectly)
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
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
what is the corona raidata
follicles still around the egg as the antrum expands isolating the egg
what happens in the ovulation phase?
tertiary follicle bursts and ovary wall ruptures, expels secondary oocyte with its corona radiata to pelvic cavity
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
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
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
what happens after ovulation?e
- estrogen levels delcine
- LH transforms ruptured follicle (corpus luteum) which releases progesterone and some estrogen
what is the role of corpus luteum
- makes progesterone and feeds back to prevent ovary from ovulating another egg
- LH regulates corpus luteum
what happens when progestrone levels decrease?
remove feedback on FSH and LJ, increase hormone again
what is the role of LH?
regulates corpus luteum and stimilates the theca and granulose cells that produce androgens
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
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
when does the uterine cycle begin and end?
first cycle at menarche (begins at puberty), cycle continues until menopause
what is the function of the uterine cycle?
prepare uterine lining for implantation of fertilized ovum, called zygote
what are the three phases of the uterine cycle?
- menstrul phase
- proliferative (preovulatory phase)
- secretory (postovulatory) phase (constant 14 days)
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
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
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