The Menstrual Cycle Flashcards
What are the 3 phases of puberty in females?
Thelarche - breast development Adrenarche - Increase in adrenal androgen secretion Menarche - Beginning of menstrual cycles
At what points in a female’s life are FSH levels highest?
Fetus
Infancy
Senescence
At what point in a female’s life is LH at its highest?
Fetus
Infancy
Monthly during reproductive years
Senescence
What phase of oocyte maturation marks gonadotropin dependency?
Formation of secondary oocyte (contains antrum)
The dominant follicle is the one that has the most ___ receptors
FSH
The time from the onset of the LH surge to ovulation is known as what? Lasts how long?
Periovulatory period
32-36 hours
What does the corpus luteum produce? When?
Large amounts of progesterone and some estrogen
A few days after ovulation
During the LH surge, ___ is released from ____ which lead to the breakdown of the follicle wall, tunica albuginea, and surface epithelium at the follicular stigma.
Inflammatory cytokines and hydrolytic enzymes from the theca and granulosa cells
What stimulates the oocyte to release TGF-B-related factor GDF9?
LH
What is the function of GDF9?
Stimulates cumulus cells to secrete hyaluronic acid and other extracellular matrix components to cause expansion of oocyte complex and make it easier to catch
What protein signals to the corpus luteum to remain viable for pregnancy?
Human chorionic gonadotropin (hCG)
During follicular atresia, what cells undergo apoptosis and what cells persist?
Apoptosis: granulosa cells, oocytes
Persist: Thecal cells - repopulate celluar stroma of the ovary
Rapid rise in what hormone(s) will eventually trigger the LH surge?
Estradiol and GnRH
In the HPO axis, what cells secrete both inhibins and activins?
Granulosa cells
Progestins and Estrogens have what effect on the hypothalamus and anterior pituitary?
Both positive and negative feedback
What is the effect of estradiol on the gonadotrophs in the late follicular phase?
Enhance sensitivity of gonadotrophs to GnRH => larger and larger releases of LH
After ovulation, what cells does LH act upon?
Cells of corpus luteum
In the female, both LH and FSH receptors are present on what steroid-producing cell?
Granulosa cells
What is the relationship of FSH and estrogen levels during the menstrual cycle?
Inversely related
More FSH released in response to low estrogen
FSH inhibited in response to high estrogen
In the late luteal phase, the demise of the corpus luteum causes a decrease in what hormones?
Progesterone
Estradiol
Inhibin
In females, where is estradiol synthesized?
Ovaries
What enzyme mediates the conversion of estrone to estradiol?
17B-Hydroxysteroid dehydrogenase (17B-HSD)
What structure of the ovary synthesizes estrogen during the follicular phase?
Follicle
What structure of the ovary synthesizes estrogen during the luteal phase?
Corpus luteum
What phase of the menstrual cycle lowers basal body temperature? Due to what?
Follicular phase
High levels of estrogen
What phase of the menstrual cycle raises basal body temperature? Due to what?
Luteal phase?
High levels of progesterone
Disintegration of the corpus luteum causes what to happen to the basal body temperature?
Decrease, signifies onset of next menstruation
The demise of the corpus luteum signals the beginning of what phase of the menstrual cycle?
Menstrual phase
What is the action of progesterone on the epithelial cells of the endometrium?
Inhibitory
What is the action of estrogen during the proliferative phase of the menstrual cycle?
Proliferation and differentiation of the endometrial stroma and epithelium
Synthesis of progestin receptors (to inhibit too much proliferation)
What hormone stimulates the early secretory phase?
Progesterone
What is the action of progesterone in the middle to late secretory phase?
Pregnancy: promotes differentiation of stromal cells into predecidual cells to decidual cells
Non-pregnancy: orchestrate menstruation
What is the action of contraceptive steroids?
Inhibit secretion of GnRH and FSH/LH and abolish folliculogenesis and ovulation
What is the progestin effect of the oral contraceptive?
Causes cervical mucus to thicken and impair sperm penetration into uterus
Impair mobility of uterus and oviducts, decreasing transport of ova and sperm
What defines menorrhagia?
Loss of >80 mL of blood
What defines dysmenorrhea?
Painful periods
What defines oligomenorrhea?
Existence of few, irregular periods
What disorders of menstruation will occur with dysfunction of HPO axis?
Oligomenorrhea and amenorrhea
What disorder is the most common cause of female sterility?
Endometriosis
What characterizes endometriosis?
Presence and growth of endometrial glands and stroma outside of the uterus instead of inside => bleeding, inflammation, and scarring
What organs/tissue does endometriosis normally involve?
Ovaries, bowel, or tissue lining the pelvis
A patient with chronic pelvic pain, dysmenorrhea, dyspareunia, rectal pain/constipation, and infertility may be diagnosed with what?
Endometriosis
What disorder is the most common cause of female infertility?
Polycystic Ovarian Syndrome (PCOS)
When does PCOS typically manifest?
During adolescence
What are some common symptoms of PCOS?
Unexplained hypreandrogenism
Anovulation
Polycystic ovary (duh)
What are the physiological characteristics of PCOS?
Abnormal ovarian steroidogenesis and folliculogenesis
Dominant follicles did not shed and instead became cysts
In PCOS, what do the levels of LH, FSH, and testosterone look like?
Elevated LH and testosterone
Decreased FSH
A young, obese, hirsute female of reproductive age presents with oligomenorrhea and infertility. What is her diagnosis?
PCOS
What disorder is the most common cause of female congenital hypogonadism?
Turner syndrome
What is the most common genotype of Turner Syndrome?
45, X
What hormone is elevated in Turner syndrome? Why?
FSH
Germ cells of the ovaries did not develop, so the ovaries are CT-filled streaks with no follicles to act upon
A female pt with short stature, absent secondary sex characteristics, webbed neck, shield-like chest, normal but infantile internal and external genitalia most likely has what diagnosis?
Turner syndrome
Due to a reduction in estrogen and inhibin, a patient undergoing menopause would most likely have elevated levels of what hormones?
FSH and LH (no negative feedback)
Menopause is officially diagnosed after how long?
12 months after the last menstrual period
What is the average age of a menopausal patient?
51.4 years
A menopausal patient with mood changes and hot flashes may be placed on what to treat her symptoms?
Antidepressants
Gabapentin
