37. Menstrual Cycle Physiology Flashcards by Deleted Deleted

Period of change when the AP gland begins to secrete progressively more FSH and LH leading to normal monthly menstrual cycles

Puberty

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_____ = breast development associated with puberty

Thelarche

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_____ =increased adrenal androgen secretion associated with puberty

Adrenarch

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Woman’s first menstrual period; avg age is 12.5 years

Menarche

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Rhythmical secretion of hormones leading to physical changes in the ovaries and uterus, including release of an ovum and preparation of the endometrium for implantation; avg 28 days

Menstrual cycle

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Absence of menses

Amenorrhea

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Absence of menarch by age 15, with secondary sexual development

Primary amenorrhea

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Menstrual periods lasting >35 days

Oligomenorrhea

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Menstrual periods lasting <21 days

Polymenorrhea

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Dysmenorrhea

Painful menses

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Metrorrhagia

Frequent or irregular menstruation

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Menorrhagia

Heavy menstrual bleeding

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Menometrorrhagia

Heavy irregular bleeding

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Which of the following organs is not directly involved with the female menstrual cycle?

A. Ovary
B. Posterior pituitary
C. Uterus
D. Anterior pituitary
E. Hypothalamus

B. Posterior pituitary

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What phases of the ovarian cycle line up with the phases of the endometrial cycle?

Ovarian follicular phase lines up with endometrial proliferative phase

Ovarian luteal phase lines up with endometrial secretory phase

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HPA regulates the menstrual cycle beginning with secretion of _____ from the hypothalamus in a _____ manner. Gonadotrophic cells become more sensitive to this hormone during the _____ phase

GnRH; pulsatile; follicular

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The anterior pituitary releases ___ and ____ in response to GnRH from the hypothalamus, contributing to menstrual cycle regulation

LH; FSH

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LH and FSH from the AP act on the ovarian theca cells to produce _____ and _______ hormones, while simultaneously acting on the ovarian granulosa cells to produce ____ and _____ hormones

Androgens; progestin

Estrogen; inhibin

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Females are born with 1-2 million ova arrested in _________. These are known as primordial follicles, which are nourished by _______ cells, which also serve the role of producing oocyte maturation inhibiting factor

Prophase 1; granulosa

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After puberty, the primordial follicles develop when FSH and LH are released from the AP. They then arrest in _______ unless fertilization occurs

Metaphase 2

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The follicular phase of the ovarian cycle begins at the onset of _______. FSH stimulates follicle development and granulosa cells produce ________, causing endometrial growth and maturation as well as an LH surge. The follicular phase is complete at around day ____, the day of that LH surge

Menses; estradiol; 14

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2 days prior to menstruation, there is a release of negative feedback on the H and AP, leading to increased production of _____

On day 1 of the menstrual cycle, the above hormone recruits several follicles. The follicles produce low levels of _____ and _____, resulting in renewed negative feedback on ______

FSH; estrogen; inhibin B; FSH

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Once follicles exert negative feedback on FSH via production of estrogen and inhibin B, ____ and _____ levels also decrease, which causes an increase in pulsatile frequency of GnRH pulsations, causing an increase in the ____:____ ratio

Progesterone; estrogen; LH:FSH

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The increase in frequency of GnRH pulsations causing an increase in the LH:FSH ratio (thus decreased FSH) causes follicular ______, and only one dominant follicle typically remains

The dominant follicle remains dependent on FSH. It produces ______ and _______. FSH induces expression of LH receptors in the mural granulosa cells of the dominant follicle

Atresia

Estradiol-17B; inhibin B

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The luteal phase of the ovarian cycle begins on the day of the LH surge, day 14. At that time, the follicle becomes the __________. Luteal cells produce ______ and ______, promoting further endometrial growth and development This phase ends at the onset of menses

Corpus luteum; progesterone; estrogen

When circulating _____ exceeds 200 pg/mL for 50 hours, it exerts a ________ feedback mechanism on the AP causing a surge of LH

Estrogen; positive

What happens as a result of the LH surge on day 14? (3 major events)

1. Primary oocyte completes meiosis, arrests in metaphase 2 2. Wall of follicle and ovary at the stigma are broken down 3. Mural granulosa cells and theca cells are restructured —> corpus luteum

During the luteal phase, the corpus luteum produces progesterone, estrogen, and _______, which exerts negative feedback on the AP. So estrogen may be >200pg/mL, but the positive feedback mechanism is inhibited by the elevated progesterone. FSH and LH are at _____ levels at this point in time

Inhibin A; basal

______ is required for corpus luteum function. If implantation does occur, ______ maintains the corpus luteum. In the absence of either of these hormones, the corpus luteum regresses and menstruation occurs

LH; hCG

In the absence of LH or hCG, as well as low progesterone, low estrogen, and low inhibin A, negative feedback on the hypothalamus is released, the corpus luteum becomes the _______, and menses occurs

Corpus albicans

A healthy 6 year old girl is brought to the pediatrician by her mother because she has had vaginal bleeding for 5 days. The patient and her mother deny having taken any medication and initial screening for sexual abuse is negative. She has been doing well in school and has no complaints of head pain or changes in her vision. Her BMI is normal. On physical exam she is normal for her age, without pubertal changes. Based on her clinical presentation, you suspect: ``` A. Sexual abuse B. Early maturation of the HPA axis C. Foreign body D. Spontaneous abortion (miscarriage) E. Endometrial hyperplasia ```

C. Foreign body

During the follicular phase, estradiol from the ovary exerts _______ feedback on the AP. During midcycle, estradiol from the ovary exerts ______ feedback on the AP. During the luteal phase, ______ from the ovary exerts negative feedback on the AP

Negative; positive; progesterone

What cell type of the ovary has LH receptors, no aromatase, and produces androgens (primarily androstenedione)?

Theca cells

What cell type of the ovary has LH and FSH receptors, contains aromatase, and produces inhibins?

Granulosa cells

T/F: Estrogen and progesterone are transported loosely bound to plasma proteins in circulation

True

During the follicular phase, the follicle primarily produces _______ During the luteal phase, the follicle primarily produces ______

Estradiol Progestins

During the follicular phase, LH primes the _____ cell to convert cholesterol to androstenedione (these cells lack aromatase). Androstenedione diffuses into _______ cells

Theca; granulosa

_____ stimulates aromatase in granulosa cells

FSH

Androstenedione can be converted to estradiol via _____ enzyme in _____ cells

Aromatase; granulosa

What hormone is responsible for maturation and maintenance of the fallopian tubes, uterus, cervix, and vagina?

Estrogen

Estrogen is associated with vaginal epithelium _______ —> stratified squamous. It is also associated with glandular tissue proliferation and enhanced cilia activity in the ______ ______

Cuboidal; fallopian tubes

What form of estrogen is most potent in the body?

Beta-estradiol > estrone > estriol

T/F: estrogen exerts negative feedback on the hypothalamus and pituitary at both high and low concentrations

True

Where is estrogen metabolized? Excreted?

Metabolized in liver; excreted in urine [so decreased liver function leads to increased activity of estrogen in the body]

What hormone maintains the secretory activity of the uterus during the luteal phase and prepares the uterus for implantation (decidualization)?

Progesterone

Estrogen is responsible for development of female secondary sex characteristics such as breast development. What aspects of breast development are promoted by estrogen?

Stromal tissue development Growth of ductile system Deposition of fat

Estrogen maintains pregnancy and lowers the uterine threshold to _____ stimuli. It also stimulates prolactin secretion

Contractile

What role does progesterone play in breast development?

Development of lobules and alveoli to ensure secretory capabilities if stimulated by prolactin

Progesterone maintains pregnancy and ______ the uterine threshold to contractile stimuli during pregnancy

Raises [contrast with estrogen which lowers uterine threshold to contractile stimuli during preg]

Progesterone is metabolized in the ____ and excreted in the ____

Liver; urine [rate of progesterone formation can be estimated from urine excretion rate — useful for counselling infertility pts]

When is progesterone concentration highest?

Between ovulation and the beginning of menstruation (day 14-28)

______ acts on the hypothalamus to increase the set point for thermoregulation about 0.5 degrees during the time of ovulation ______ serves a neuroprotective function at this time

Progesterone Estrogen

Disintegration of the corpus luteum (d/t lack of fertilization) causes a subsequent _____ in basal body temperature, and menstruation occurs

Drop

Inhibins are produced by granulosa cells of the follicle when stimulated by _____. ____ produced just prior to ovulation also stimulates production

FSH; LH

_______, produced by granulosa cells of the follicle, inhibit FSH production by gonadotropes but do not have an effect on GnRH itself (via negative feedback)

Inhibins

T/F: inhibins inhibit LH production

False; inhibins have no effect on LH (activins have no effect on LH either)

Inhibins cause a _____ in intraovarian production of androgens, and therefore estrogens

Decrease

Compare/contrast structures of inhibins vs. activins

Inhibins = 1 alpha, 1 beta subunit Activins = 2 beta subunits

______ are produced by granulosa cells as well as in several extragonadal tissues. They stimulate production of FSH by gonadotropes, independent of GnRH action

Activins

Activins increase intraovarian production of ______, but have no effect on LH

Estrogens

The mid-cycle surge of LH leads to increased production of progesterone to maintain the endometrial lining of the uterus. How many days pass between the LH surge and corpus luteum regression (menses)? A. 10 days B. 14 days C. 18 days D. 28 days

B. 14 days [regardless of cycle length, ovulation occurs 14 days prior to start of menses]

The menstrual cycle results in 25-35 mL of total blood loss. A decrease in _____ and _____ indicate corpus luteum regression, leading to withdrawal of hormonal support from endometrium.

Estradiol; progesterone

During menses, _______ breakdown the stratum functionalis. ______ lead to hypoxic necrosis of the spiral arteries, and shedding of the functional layer occurs

Matrix Metalloproteinases (MMPs); prostaglandins

During the proliferative phase, antral follicles begin producing ______ (especially with dominant follicle) The endometrium proliferates 0.5mm to 5mm, and there is development of straight or coiled uterine glands This induces expression of _____ receptors, allowing endometrium to respond to this hormone during the luteal phase

Estradiol; progesterone

During the secretory phase of the endometrial cycle, ______ inhibits endometrial growth by downregulating estrogen receptors (this is done by activating enzymes that inactivate estrogen and convert estradiol —> ______)

Progesterone; estrone

During the secretory phase of the endometrial cycle, progesterone induces differentiation of epithelial and ____ cells, as well as induces production of nutrient rich secretion from uterine glands. In addition, it alters the _____of the surface epithelium

Stromal; adhesivity

What is the most common cause of congenital (primary) hypogonadism?

Turner syndrome (gonadal dysgenesis)

Those with turner syndrome have what genotype/phenotype combo?

Female; 45, XO

Describe turner syndrome

Internal and external genitalia are female but ovaries fail to develop Serum FSH is very high bc it is trying to stimulate ovaries that are not functional. Germ cells do not develop, ovaries appear as a CT filled streak = STREAK OVARIES

Characteristics seen in someone with Turners syndrome

``` Short stature Shield chest Bicuspid aortic valve Coarctation of aorta Low set ears Short 4th metacarpals Lymphatic defects Sexual infantilism Amenorrhea ```

Diagnosis of PCOS requires 2/3 of what 3 criteria?

1. Amenorrhea 2. Evidence of excess androgen secretion (acne, hirsutism) 3. Polycystic ovaries [ovaries described as “string of pearls”]

PCOS results with a continuous secretion of _____, leading to ovarian enlargement and excess androgen production from _____ cells

LH; theca

In PCOS, the elevated levels of androgens result in some being converted to _____ in ______ tissue. Increased levels of this hormone feed back to inhibit FSH secretion, which inhibits follicular maturation and decreases the release of _______

Estrone; adipose; 17B-estradiol

Symptoms of PCOS

Menstrual dysfunction (amenorrhea) Hyperandrogenism (acne, hirsutism, male pattern hair loss) Polycystic ovaries Metabolic issues/cardiovascular risks (obesity, insulin resistance, T2D) Infertility

Endometriosis occurs when endometrial glands implant outside the endometrial cavity. Where are the 3 most common locations?

Ovary Pelvis Peritoneum

What are theories as to how endometriosis develops?

Retrograde flow Metaplastic transformation of multipotent cells Lymphatic transport of endometrial tissue

Signs/symptoms of endometriosis

``` Cyclic abdominopelvic pain Dysmenorrhea Dyspareunia Dyschezia Heavy menstrual bleeding Tenderness on vaginal exam Infertility ```

Tx for endometriosis

``` NSAIDs OCPs Progestins and other hormones Laparascopic removal GnRH agonist ```

Define menopause

12 consecutive months without menstruation; avg age = 51

Hormonal changes during menopause

Decreased estrogen, along with increased LH and FSH d/t lack of negative feedback Estrone, synthesized from circulating androgens, becomes primary form of estrogen

Causes of menopause

Natural Premature ovarian failure Surgical Chemotherapy

Signs/symptoms of menopause

``` Irregular menstruation Vaginal dryness Hot flashes Night sweats Sleep problems Mood changes Dec. metabolism, weight gain Thinning hair, dry skin Loss of breast fullness ```

Tx for menopause

Relief of s/s — estrogen therapy (vaginal, topical, oral) Management of comorbid conditions

A 20 year old female college cross country runner comes to the infirmary with a chief complaint of no periods and believes she may be pregnant. She has not had a menstrual cycle in 3 months and would like a pregnancy test. Your nurse ran a pregnancy test on the urine specimen the patient provided prior to being roomed and the result is negative. On further questioning she denies nausea, vomiting, lightheadedness, dizziness, chest pain, palpitations, hot flashes, mood swings, nipple discharge, any changes in her vision and any new male pattern hair growth. She is sexually active in a monogamous relationship and uses condoms 100% of the time. She has run cross country since middle school and has really ramped up her training and discipline with her diet this year so that she can be a contender at the Olympic trials. On arrival, her vitals were: BP 102/65, P 54, T 98F, BMI 16 You suspect: ``` A. Primary amenorrhea B. Secondary amenorrhea C. Pregnancy D. Ovarian failure E. Prolactinoma ```

B. Secondary amenorrhea