37. Menstrual Cycle Physiology Flashcards
Period of change when the AP gland begins to secrete progressively more FSH and LH leading to normal monthly menstrual cycles
Puberty
_____ = breast development associated with puberty
Thelarche
_____ =increased adrenal androgen secretion associated with puberty
Adrenarch
Woman’s first menstrual period; avg age is 12.5 years
Menarche
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
Absence of menses
Amenorrhea
Absence of menarch by age 15, with secondary sexual development
Primary amenorrhea
Menstrual periods lasting >35 days
Oligomenorrhea
Menstrual periods lasting <21 days
Polymenorrhea
Dysmenorrhea
Painful menses
Metrorrhagia
Frequent or irregular menstruation
Menorrhagia
Heavy menstrual bleeding
Menometrorrhagia
Heavy irregular bleeding
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
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
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
The anterior pituitary releases ___ and ____ in response to GnRH from the hypothalamus, contributing to menstrual cycle regulation
LH; FSH
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
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
After puberty, the primordial follicles develop when FSH and LH are released from the AP. They then arrest in _______ unless fertilization occurs
Metaphase 2
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
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
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
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
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)
- Primary oocyte completes meiosis, arrests in metaphase 2
- Wall of follicle and ovary at the stigma are broken down
- 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
