Menstrual Cycle And Reproductive Endocrinology Flashcards
(21 cards)
What does the hypothalamus secrete and what does it do
GnRH, which controls pituitary hormone secretion
The pituitary gland releases FSH and LH, this is modulated through which two sex steroids?
Oestrogen and progesterone
Which sex steroid is negative and which is positively feeding back the pituitary gland?
Estrogen negative, progesterone positive
What is the most active and predominant Oestrogen?
Oestradiol
Tissues in two places are most affected by the circulating oestradiol, which are they
The genital tract and lobular elements of the breast
what does Oestradiol do
Maintaining sexual characteristics like growing the vagina and vulva
So how essentially is Oestrogen useful in pregnancy?
It’s what causes the rapid growth of the uterus
Mutations in receptor for Kisspeptin is associated with a delay in what
Puberty
How long does the follicular phase last
14 days
By the end of the follicular phase, the dominant follicle would have grown to be how big?
20mm in diameter
When the follicular phase begins, Oestrogen production increases till it reaches the necessary threshold to exert positive feedback on the hypothalamus and pituitary, what is the threshold
> 200mpg/ml for 50 hours
The best predictor of an imminent ovulation is called?
The LH surge. Occurs around day 14
The falling of the circulating levels of progesterone that happens if no pregnancy occurs by the luteal phase, leads to what?
The shedding of the endometrium, and as such menstruation
What is the mean blood loss for menstruation
10-80ml
Which hormone is primarily responsible for the thermogenic effect observed during the luteal phase?
Progesterone
What is the role of inhibin during the follicular phase?
Downregulates FSH release
During the luteal phase, what maintains the corpus luteum if pregnancy occurs?
hCG from trophoblastic cells
What is the primary role of pinopodes in the endometrium?
Facilitate implantation
When is the best time to measure progesterone levels to confirm ovulation in a 28-day cycle
Day 21
