Female reproductive cycle Flashcards
The ovarian cycle occurs in the …………. of the ovary.
Cortex
Mention the three phase of the endometrial cycle
- The follicular phase ( in the first half of the cycle)
- Ovulation (at about the middle of the cycle)
- The luteal phase (in the second half of the cycle.
The other follicles that don’t mature into a grafian follicle undergo atresia (degeneration), forming ………………….
Corpus atreticum
The developing Graafian follicle secretes ……………….., which is responsible for the proliferative phase of uterine cycle.
oestrogen
FSH is secreted by ……………………
FSH is secreted by the anterior pituitary gland.
What are the effects of oestrogen?
•Causes the uterine endometrium to enter into
follicular or proliferative phase
•Cause thinning of cervical mucus to allow passage of sperm
•Stimulate the pituitary gland to secrete LH.
What activities does the LH surge lead to?
•Elevates concentration of maturation-promoting factors, causing oocytes to complete meiosis I and initiate Meiosis II
•Stimulate the production of Progesterone by follicular stromal cells (Luteinisation)
•Cause follicular rupture and Ovulation.
………………. is the process of rupture of the Graafian follicle and release of matured ovum from the ovary
Ovulation
The time of ovulation is variable but it is usually on the ………. day of the ovarian cycle.
14th
The cause of ovulation is attributed to ………
Inhibition of FSH
Stimulation of LH secretion by the anterior pituitary
………………. phase is about the formation of corpus luteum and secretion of progesterone hormone
Luteal phase
The follicular phase is also known as …………..
preovulatory, estrogenic phase
The luteal phase is also know as ………..
postovulatory, progestational phase
A short note on corpus hemorrhagicum
Following ovulation the residual granulosa cells and thecal interna cells in the wall of ruptured follicle, become vascularized by surrounding blood vessels. The wall of the ovarian follicle collapses and become folded due to sudden release of the pressure inside it. Bleeding therefore occurs inside the follicle with the formation of a blood clot. This stage last for about 3 days before it changes into corpus luteum.
A short note on the corpus luteum;
The ruptured follicle is gradually transformed into the corpus luteum. The granulosa cells enlarge, become polyhedral and develop a yellowish carotenoid pigment, lutein
Corpus luteum has the function of secreting ……………..
progesterone, and small amount of estrogen.
The persistence of corpus luteum of pregnancy is induced by …………………
Human Chorionic Gonadotropin (HCG)
HCG is secreted by ……………
The placenta
What is the fate of the corpus luteum?
If there is no fertilization, it persists for 9-14 days (corpus luteum of menstruation), then rapidly degenerate to become the corpus albicans (fibrous body).
But if fertilization occurs, the corpus luteum persists for 4 months (corpus luteum of pregnancy), then slowly degenerate, and its function is taken by the placenta. The persistence of corpus luteum of pregnancy is induced by Human chorionic gonadotropin (hCG), which is secreted by the placenta
Describe the hormonal control of the ovarian cycle
• The anterior pituitary gland secretes follicle stimulating hormone (FSH) that causes maturation of primary ovarian follicle, to the mature Graafian follicle, and consequently secretion of oestrogen by the grafian follicle.
• In the mid cycle, oestrogen inhibits FSH secretion and stimulates the secretion of LH by the anterior pituitary and LH causes ovulation.
•In the second half of the cycle, LH changes the corpus haemorrhagicum into corpus luteum and LH stimulates corpus luteum to secrete progesterone and small amounts of oestrogen.
•Progesterone inhibits the production of LH, leading to regression of the corpus luteum
•Decreasing oestrogen level stimulates FSH secretion and a new cycle starts.
………….. stimulates FSH secretion
Decreasing oestrogen level
…………….. inhibits the production of LH
Progesterone
…………………… leads to regression of the corpus luteum
Inhibition of LH production
………. stimulates a new cycle
FSH secretion
…………….. changes the corpus haemorrhagicum into corpus luteum
LH
………….. stimulates corpus luteum to secrete progesterone and small amounts of oestrogen
LH
…………….. inhibits FSH secretion
Oestrogen
………….. stimulates the secretion of LH by the anterior pituitary
Oestrogen
…………. hormone causes ovulation
Leutinizing hormone
………………… causes maturation of primary ovarian follicle to Graafian follicle
Follicle stimulating hormone (FSH)
……………. secretes oestrogen
Graafian follicle
The menstrual cycle occurs in the ……………. of the uterus
endometrium