Term
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Definition
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Term
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Definition
| Any hormone secreted from cells (gonadotrops) in the anterior pituitary that have an effect on reproductive organs |
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Term
| What are 2 gonadotropins important to the menstrual cycle? |
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Definition
FSH-Follicle Stimulating Hormone
LH-Luteinizing hormone. |
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Term
| What 3 structures regulate the menstrual cycle |
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Definition
The Hypothalamus
The Pituitary Gland
The Ovaries |
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Term
| What is the most common menstrual cycle pattern |
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Definition
| 28-day cycle but that accounts for only 12.4% |
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Term
| What is the range of cycle lengths? |
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Definition
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Term
| When does the corpus luteum begin to atrophy |
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Definition
| 9-11 days after ovulation |
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Term
| How many women experience irregular cycles? |
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Definition
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Term
| What are the four phases of the menstrual cycle |
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Definition
1) Follicular (pre-ovulatory)
2) Ovulatory
3) Luteal
4) Menstrual |
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Term
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Definition
| Gonadotropin releasing hormone is a neurohormone that is released from the hypothalmus & travels to the anterior pituitary to simulate gonadotropes to produce and release FSH & LH |
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Term
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Definition
| In a pulsatile manner every 60-90 minutes |
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Term
| How are FSH and LH released and from where? |
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Definition
| FSH and LH are released from the anterior pituitary in a pulsatile manner. Pulse frequency depends on the phase of the cycle one is in. |
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Term
| Which hormone plays a dominant role in the promotion of ovarian follicular growth and how? |
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Definition
| FSH plays the dominant role by stimulating the granulosa cells that line each follicle to proliferate and produce estrogen. |
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Term
| Name two cell types within a follicle. |
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Definition
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Term
| What role does LH play in relation to the follicle? |
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Definition
| LH stimulates androgen production in the theca cells |
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Term
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Definition
| 2 androgens are testosterone and androstenedione which diffuse from theca cells across the basement membrane of the follicle to the granulosa cells where they are converted to estrogen by the enzyme aromatase. |
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Term
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Definition
| Aromatase is an enzyme that converts androgens (testosterone and androstenedione to estrogen in the granulosa cells |
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Term
| What is the role of LH after ovulation? |
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Definition
| LH converts estrogen-secreting granulosa cells to progesterone-secreting cells after ovulation. |
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Term
| Which hormone promotes ovulation and final oocyte maturation? |
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Definition
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Term
| What does the two-cell, two-gonadotrophin theory say? |
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Definition
| At the beginning of an ovulatory cycle, the outer theca cells can only be stimulated by LH and the inner granulosa cells can only be stimulated by FSH. Theca cells have little intrinsic aromatase activity and granulosa cells are deficient in the enzymes necessary to produce androgens. The 2 cell types are dependent on each other to produce estrogen in the developing follicle. |
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Term
| What happens if there is an excess of androgens? |
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Definition
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Term
| At low levels androgens have what 2 effects on granulosa cells? |
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Definition
| They are the substrates for conversion to estrogen and they stimulate aromatase activity. |
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Term
| What is the effect of estrogen production on FSH and LH? |
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Definition
| Estrogen acts on both the hypothalamus and the anterior pituitary to inhibit FSH and LH secretion in a classic negative feedback loop. |
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Term
| What is the paradoxical effect of estrogen mid-cycle? |
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Definition
| Higher levels of estrogen have a positive feedback effect on gonadotropin secretion during the middle of the cycle which initiates the preovulatory surge of LH and FSH. |
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Term
| What feedback effect do progesterone and androgens have on gonadotropin release? |
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Definition
| They also have a negative feedback but it's not as prominent as that of estrogen. |
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Term
| What levels of estradiol are needed for a gonadotrophin surge? |
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Definition
| When estradiol levels are at 200-300 picograms/ml for 2-3 days, a surge is elicited. |
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Term
| What helps to amplify the positive estrogen feedback effect prior to ovulation? |
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Definition
| Low levels of progesterone produced prior to ovulation |
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Term
| Where is the major site for the positive feedback effect of estradiol? |
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Definition
| The anterior pituitary is the major site although there may be some hypothalamic action as well. |
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Term
| What is critical for ovulation and regular menstrual cycles to occur? |
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Definition
| The positive feedback effect of estrogen on the anterior pituitary. |
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Term
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Definition
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Term
| What do peptide hormones do and where are they produced? |
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Definition
| They are produced in the ovary to help modulate follicular devlopment and steroid production. |
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Term
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Definition
| Inhibin is a protein composed of alpha and beta subunits produced in the granulosa and theca cells of the ovary which suppresses FSH secretion. |
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Term
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Definition
| Activin is composed of two beta subunits of inhibin but has the opposite effect of inhibin in that it enhances FSH secretion. |
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Term
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Definition
| A peptid hormone the suppresses FSH probably by binding with activin. |
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Term
| Inhibin and activin regulate what within the ovary? |
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Definition
| Androgen and estrogen production. |
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Term
| Which peptid is prominent in ovarian follicular fluid? |
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Definition
| There is more inhibin than activin in ovarian follicular fluid so the dominent follicle has a negative feedback effect on FSH. |
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Term
| What does IGF-1 (Insulin like growth factor) do? |
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Definition
| Stimulates cell division and growth in many tissues. Found to be produced and active in the ovary to ampligy LH-stimulated androgen production in theca cells and to amplify FSH action in granulosa cells. It may also facilitate communication btwn theca and granulosa cells. |
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Term
| What is Oocyte maturation inhibitor or OMI? |
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Definition
| A peptide hormone present in follicular fluid that prevents final maturation of the oocyte until the time of ovulation. |
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Term
| When does OMI suppression end? |
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Definition
| Within hours following the midcycle LH surge just prior to ovulation. |
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Term
| What are 3 main effects of estrogen on the endometrium? |
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Definition
1) Estrogen increases the thickness by increasing the # and size of endometrial cells.
2) Stimulates the formation of progesterone receptors on endometrial cells
3) Increases blood flow (via spiral arterioles) to the endometrium. |
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Term
| What effect of progesterone on the endometrium is especially important for a developing embryo? |
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Definition
| Progesterone causes the proliferated endometrium to differentiate and secrete proteins important for the survival and implantation of an early embyo if pregnancy occurs. |
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Term
| What effect does progesterone have on estrogen in regards to the endometrium? |
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Definition
| Progesterone and exogenous progestins decrease the proliferative effects of estrogen by causing down regulation of estrogen receptors. |
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Term
| If a pregnancy does not occur, what happens to the endometrium? |
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Definition
| Withdrawal of estrogen and progesterone results in the orderly and controlled sloughing of the functional zone of the endometrium. |
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Term
| Which hormone causes cervical mucous to become thin, clear, elastic, and more profuse? |
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Definition
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Term
| During which phase of the menstrual cycle is cervical mucous clear, thin, and more profuse? |
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Definition
| Peri-ovulatory-mid to late follicular phase |
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Term
| Just prior to ovulation, what effects does estrogen have on the cervix? |
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Definition
| It causes it to swell, soften, and the cervical os to dilate. |
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Term
| What effect does progesterone have on the cervix following ovulation? |
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Definition
| Progesterone causes the cervical os to close and the cervix to become firm. |
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Term
| What effect does progesterone have on cervical mucous? |
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Definition
| Following ovulation, progesterone causes cervical mucous to become thick, scant, and turbid so that sperm cannot penetrate. |
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Term
| During which days of the cycle are follicles FIRST recruited? |
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Definition
| Early follicular phase...days 1-5. |
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Term
| increasing local estradiol levels have what effect on the dominant follicle? |
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Definition
| It induces more FSH receptors on the largest follicle to form thereby producing even greater levels of estradiol. |
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Term
| On what days of the cycle does one of the follicles become "dominant"? |
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Definition
| days 5-7 of the follicular phase |
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Term
| How does one follicle become dominant? |
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Definition
It produces the most estradiol
It develops the most FSH receptors
It has the largest # of granulosa cells |
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Term
| What happens when FSH and inhibin levels begin to decline as a result of the negative feedback loop? |
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Definition
| The dominant follicle survives while non-dominant follicles undergo atresia. |
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Term
| The dominant follicle is selected around day 7, what does it do during the rest of the follicular phase? |
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Definition
| It continues to produce high levels of estradiol and mature. |
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Term
| Which phase of the menstrual cycle is more variable in length from individual to individual? |
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Definition
| The follicular phase lasting anywhere from 10-17 days |
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Term
| On a typical 28 day cycle, how long is the menstrual phase? |
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Definition
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Term
| On a 28 day cycle, how long is the proliferative phase? |
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Definition
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Term
| on a 28 day cycle, how long is the secretory phase? |
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Definition
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Term
| During the follicular phase, what amount of FSH and LH are being released up until the surge? |
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Definition
| FSH is around 10-12 mIU and LH is 15 mIU |
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Term
| How much FSH and LH is released during the surge? |
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Definition
| FSH goes up to 25 mIU and LH goes up to 50-100 mIU |
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Term
| How much progesterone and estrogen is secreted during the follicular phase before the surge? |
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Definition
| Estrogen is 40 pg and Progesterone is 1 ng |
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Term
| What level does estrogen spike to just prior to the surge? |
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Definition
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Term
| Following ovulation, what are progesterone and estrogen levels during the luteal phase? |
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Definition
| estrogen is 125-250 pg and progesterone is 10-15 ng |
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Term
| What is the normal blood loss during the menstrual phase? |
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Definition
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Term
| What is the average endometrial height following the mentrual phase? |
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Definition
| 2mm and climbing during the follicular phase |
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Term
| How thick does the endometrial lining become by the luteal phase? |
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Definition
| 4mm or double that following menstruation. |
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Term
| By what day is HcG detectible is a pregnancy has occurred? |
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Definition
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Term
| When can you see ferning in cervical mucous? |
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Definition
| Just prior to ovulation when mucous is thin, clear, and increased in amount with high elasticity (Spinnbarkeit) |
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Term
| What days describe the Secretory phase? |
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Definition
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Term
| When does BBT or basal body temperature increase? |
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Definition
| day 15 with the highest point on day 17. |
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Term
| During ovulation, is the BBT low or high? |
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Definition
| low. It is at the lowest point of the entire cycle and spikes following ovulation. |
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Term
| During the ovulatory phase what happens to libido and why? |
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Definition
| Libido increases due to a rise in androgen levels. Androstendedione rises by 15% and testosterone rises by 20%. |
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Term
| When do estradiol levels reach their peak? |
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Definition
| About 24 hours before ovulation. |
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Term
| Resumption of meiosis in the dominant oocyte occurs from what? |
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Definition
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Term
| What causes the follicular wall to break down? |
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Definition
| Prostaglandins, proteolytic enzymes, and smooth muscle cell ctx within the follicle. |
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Term
| Luteinization of granulosa cells resulting in progesterone production is caused from what? |
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Definition
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Term
| When does the follicular fluid and oocyte exude from the follicle? |
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Definition
| about 32-44 hours following the start of the LH surge and 10-12 hours following the peak of LH. |
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Term
| How do ovulation predictor kits work? |
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Definition
| They detect the onset of the LH surge predicting impending ovulation. |
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Term
| How is the corpus luteum formed? |
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Definition
| Following rupture of the follicle, the granulosa and theca cells take up steroids and lutein pigment to give the corpus luteum a yellow appearance "yellow body" is the other name for the CL. |
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Term
| What is the hallmark of the luteal phase? |
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Definition
| A shift from estrogen dominance to progesterone dominance. |
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Term
| What role does progesterone have in the luteal phase? |
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Definition
| It suppresses follicular development and causes secretory changes in the endometrium in preparation for implantation. |
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Term
| When is the peak in progesterone production? |
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Definition
| 7-8 days following the LH surge when implantation would occur. |
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Term
| Which phase is more consistent in length from individual to individual? |
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Definition
| The luteal phase lasting 14 days unless pregnancy has occurred. |
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Term
| What causes the spike in BBT? |
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Definition
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Term
| Can BBT be used to predict ovulation? |
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Definition
| No because it only rises following ovulation when progesterone increases. It can only confirm ovulation has occurred. |
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Term
| If no pregnancy has occurred, when does the CL begin to atrophy? |
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Definition
| 9-11 following ovulation. |
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Term
| What happens to hormone levels when CL atrophy occurs with no pregnancy. |
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Definition
| There is a decline in both estrogen and progesterone which initially shrinks endometrial height, decreases blood flow, and begins vasodilation followed by rhythmic vasoconstriction of the spiral arterioles |
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Term
| What causes menstrual flow? |
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Definition
| Withdrawal of estrogen and progesterone causes rhythmic vasoconstiction of spiral arterioles, ischemia and stasis are followed by interstitial hemorrhage and tissue disorganization resulting in flow. |
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Term
| What is the average length of the menstrual phase? |
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Definition
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Term
| What is a possible cause of heavier longer periods? |
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Definition
| Delayed, asynchronous, or incomplete shedding of the endometrium, as might occur in anovulatory cycles, can be associated with heavier longer bleeding. |
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Term
| When is a women MOST likely to conceive? |
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Definition
| If fresh sperm are in the upper reproductive tract when ovulation occurs. |
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Term
| How long does the oocyte maintain the potential for fertilization? |
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Definition
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Term
| How long does sperm remain viable in the reproductive tract? |
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Definition
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Term
| What are the most fertile days? |
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Definition
| The several days prior to ovulation. |
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Term
| When is pregnancy less likely to occur? |
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Definition
| Following ovulation and the very early follicular phase. |
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Term
| Do cervical mucous and semen mix? |
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Definition
| NO. They don't mix so the sperm have to pass into the cervical mucous but this occurs within minutes. |
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Term
| About how many sperm are in seminal fluid? |
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Definition
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Term
| How long does it take for sperm to reach the fallopian tubes and how long are they present in cervical crypts? |
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Definition
| They reach the tubes pretty rapidly and can remain in the crypts for several days supplying the upper reproductive tract. |
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Term
| How long does it take the oocyte to reach the tube? |
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Definition
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Term
| Where does fertilization occur |
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Definition
| In the ampulla of the tube. |
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Term
| How long does it take a fertilized egg to reach the uterine cavity? |
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Definition
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Term
| When does implantation occur? |
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Definition
| 6-7 days after fertilization when embryo is in the blastocyst stage. |
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Term
| True or False? It can take several years following menarche for cycle to become regular and ovulatory. |
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Definition
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Term
| True or False. Cycles are longer in women 20-40 years of age. |
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Definition
| False. Cycle length tends to be longer in women under 20 and over 40. |
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Term
| Inadequate GnRH would result in what? |
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Definition
| It would inhibit FSH and LH production and result in anovulation. |
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Term
| What things can interfere with GnRH production? |
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Definition
| Stress, extensive exercise, weight loss, depression, and anorexia nervosa. |
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Term
| Hyperprolactinemia can cause? |
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Definition
| ovulatory dysfunction or anovulation. |
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Term
| Excessive androgen production in the follicle causes what? |
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Definition
| follicular atresia by inhibiting the development of a dominant follicle. |
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Term
| Name something that can cause excessive androgen production. |
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Definition
| Hyperinsulinemia as is seen in those with polycystic ovarian syndrome. |
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Term
| Combined oral contraceptives contain which two hormones? |
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Definition
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Term
| Which contraceptives contain progestin only? |
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Definition
| Depo-provera, Norplant, minipills, and IUDs |
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Term
| How does the estrogen in birth control work? |
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Definition
Estrogen suppresses FSH and LH thus preventing the pituitary gland from releasing the ovary stimulating hormones.
Alters endometrial secretions and cellular structure.
Altered local levels of prostaglandins contribute to the degeneration of the CL. |
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Term
| How does progesterone in birth control work? |
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Definition
Suppresses the mid-cycle peak of FSH and LH
Thickens cervical mucous
Reduces activity of cilia on the fallopian tubes
Causes endometrial atrophy impairing implantation. |
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Term
| The follicle destined to ovulate in recruited when? |
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Definition
| in the first few days of the cycle |
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Term
| Follicles for a current cycle started development a few cycles prior...T or F |
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Definition
| True. Total time to achieve pre-ovulatory status is 85 days. |
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Term
| What is the critical feature in the rescuing of a cohort of follicles from atresia? |
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Definition
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Term
| Where do primordial germ cells originate? |
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Definition
| In the endoderm of the yolk sac, allantois, and hindgut of the embryo and by 5-6 weeks gestation they have migrated to the genital ridge. |
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Term
| When are the maximum number of oocytes reached? |
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Definition
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Term
| Describe the primordial follicle. |
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Definition
| non-growing, consists of an oocyte arrested in the doplotene stage of meiotic prophase, surrounded by a single layer of granulosa cells. |
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Term
| follicles are constantly growing and going through apoptosis even during pregnancy and menopause T or F? |
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Definition
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Term
| The term "recruitment" describes what? |
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Definition
| the continuing growth of antral follicles in response to FSH. Another way to think of it is that a cohort of follicles is rescued from apoptosis. |
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Term
| How many follicles will actually ovulation during a women's reproductive years? |
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Definition
| 400. Most follicles will undergo apoptosis. |
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Term
| Early development of follicles occurs without influence of gonadotropin T or F? |
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Definition
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Term
| What are the first visible signs of follicular development? |
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Definition
| Increase in size of the oocyte and the granulosa cells becoming cuboidal instead of squamous in shape. Gap junctions develop btwn the granulosa cells and the oocyte. |
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Term
| What signals go across the gap junction btwn the oocyte and the granulosa cells? |
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Definition
| Inhibition of the final maturation of the oocyte (until the LH surge) is maintained by factors derived from the granulosa cells and follicular growth is influenced by regulatory factors that originate in the oocyte. |
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