The Menstrual Cycle Flashcards
Quick review of the feedback loop of HPO axis:
GnRH produced by:____
FSH and LH by:_____
Sex steroids from the: _____
Hypothalamus
Anterior pituitary
Ovaries
The hirmone that is produced by the ovaries to inhibit secretion of anterior pituitary hormones is
Inhibin
The hormone that is produced by the ovaries to promote secretion of anterior pituitary hormone is
Activin
Which phase promotes the positive feedback?
Follicular phase
Which phase promotes the negative feedback?
Luteal phase
The hormones FSH, LH activates the anterior pittuitary to produce estrogen, progesteron and activin to reguylate the menstrual and ovarian cycle
True or false
FALSE
The hormones FSH, LH activates the anterior pittuitary [ovaries] to produce estrogen, progesteron and activin [inhibin] to reguylate the menstrual and ovarian cycle
True about GnRH
A. Reguylates secretion of FSH and LH
B. Secreted in cyclical manner to be effective
C. Released from the neurons within the anterior hypothalamus (arcuate nucleus of the median basal hypothalamus)
D. Both A and C
E. NOTA
D
Gonadotropins:
A. FSH
B. LH
C. GnRH
D. A and B
E. AOTA
D.
True or False
The structural similarity of FSH and LH is at the alpha subunit and variews at the beta subunit
True
FSH acts on ____ cells of the ovarian follices to stimulate ____ growth
Granulosa cells
Follicular growth
hence the name follicular stimulating hormone
LH acts on ____ (2) cells for the purpose of stimulating ovarian steroid production.
Theca and granulosa cells
The leutenizing hormone leutenizes both cells turning them into:
Granulosa-lutein cells
Theca-lutein cells
Give three examples of the sex steroids that is produced by the ovaries
- Estradiol
- Progesterone
- Androgen
Secretion is regulated by FSH
• For development of secondary sex characteristics at puberty
• Thickens endometrium during the proliferative phase
Estrogen
Secretion is regulated by LH
• Maintains endometrium during secretory phase
• Prepares endometrium for implantation ( during pregnancy)
Progesterone
The secretory phase is a phase of endometrial cycle‼️
• Regulated by LH
• At low concentrations, these are transported to the granulosa cells
for aromatization to estradiol & estrone (two-cell two-gonadotropin
mechanism of steroidogenesis)
• At high concentrations (such as in PCOS), they are converted to 5-alpha
reduced androgens that cannot be converted to estrogens and inhibit
aromatase activity (this causes the atresia of follicles)
Androgen
Interval of cyclical ovulation occurs at:
21 to 35-day intervals
How long cyclical ovulation almost lasts??
Clue: One generation
40 years
Cyclical ovulation starts at____ and ends at_____.
Menarche
Menopause
At day 20 to 24 of the menstrual cycle, the endometrium is receptive enough for the implantation of the blastocyst.
True/ Flase
True
Components of the Menstrual Cycle by organ
Ovaries (ovarian cycle)
Uterus (endometrial cycle)
The mesntrual cycle od divided into two 14 days phases, which are the:
Ovarian cycle
Endometrial cycle
Ovarian cycle is divided into two 14’s that are namely:
1-14: ____
15-28: ___
And is described with remarkable changes in the:____
1-14
Follicular
15-28
Luteal
Changes in the ovaries
Endometrial cycle is divided into two 14’s that are namely:
1-14: ____
15-28: ___
And is described with remarkable changes in the:____
1-14
Proliferative
15-28
Secretory
Changes in the endometrium
Normal dimensrions of Mestruation:
Frequency of Menses:
Duration of Menses:
Regularity of Menses:
Flow volume:
- Every 24-38 days
- Less than or equal to 8 days
- Shortest to longest cycle variation is less than or equal to 7-9 days
- Less than 80 mL blood loss per cycle
The body temperature is____ at the luteal phase [secretory phase of the endometrium]
A. Increased
B. Decreased
A. Increased
The body temperature is____ at the luteal phase [secretory phase of the endometrium]
A. Increased
B. Decreased
A. Increased
The anterior pituitary releases ___ and ___ at the start of the ____ and decreases at the _____ phase.
FSH and LH
Follicular; Luteal
This phase is characterized by increasing estrogen, thick endometrium and selection of dominant ovulatory follicle
Follicular phase
This phase is is described and characterized by the corpus luteum producing estrogen and progestrone to prepare the endomentrium for implantation
Luteal phase
If implantation happens, the HCG produced by the ____ will sustain the progesterone that is produced by the ___.
Blastocyst
Corpus luteum
This describes the process that the corpus luteum undergoes when there is absence of pregnancy.
Involution. Rapid regression in 9-11 days after ovulation.
The ovarian cycle is divided into two phases which are:
Follicular and luteal phase
Th drop in progesterone triggers the shedding of endometrium
True or false
True
As the estrogen _____ the FSH ____ too.
A. Increase; increase
B. Decrease; increase
C. NOTA
B.
The selective negative feedback is exhibited by increase in ______
Estrogen
The non-selective negative feedback is exhibited by increase in ______
Progesterone
Progesterone is the main hormones in what phase?
Luteal phase
Which surge comes first and is followed by the next?
Estradiol surge then LH
Trigger for ovulation. Enables production of the granulosa cells of progesterone
A. LH surge
B. Estradiol surge
A.
The _____ involves the maturation of the follicles. Initiation of menstruation and averages 14 days in length.
Follicular phase
Gradual increase of FSH that stimulates growth of primordial ovarian follicles
A. Recruitment of cohort of antral follicles
B. Selection of a dominant follicle
C. Growth of the dominant follicle
A.
Of the primordial follicle there will be one that will be selected and called as the ‘____’ follicle
Dominant
The follicle that ahas the most vacularized theca layer and a higher number of gonadotropin receptors
A. Recruitment of cohort of antral follicles
B. Selection of a dominant follicle
C. Growth of the dominant follicle
B.
Two cell Gonadotropin theory states that:
LH» LH receptor
Two cell Gonadotropin theory states that:
LH» LH receptor
