The flashcards below were created by user
camturnbull
on FreezingBlue Flashcards.
-
How long is the typical menstrual cycle?
28 days
-
By which hormones is the menstrual cycle controlled?
- Follicle stimulating hormone (FSH)
- Luteinising hormone (LH)
- Oestrogen
- Progesterone
-
From where is FSH secreted and what becomes of it?
- The pituitary gland
- The FSH travels in the blood stream, stimulating the follicle containing the egg to develop and mature
-
Other than follicle maturation, what is the function of FSH?
It causes the follicle cells to secrete oestrogen
-
What effects does oestrogen have?
- It binds to oestrogen receptors inside the cells of the endometrium
- This activates transcription within cells lining the wall of the uterus, causing it to repair and thicken
-
What happens to the hormone levels between days 1 and 10 of the menstrual cycle?
- Oestrogen levels rise slowly
- Oestrogen inhibits the production of FSH
- This is an example of negative feedback
-
What happens to the hormone levels between days 10 and 14 of the menstrual cycle?
There is a rapid rise in the levels of oestrogen causing positive feedback
-
What happens to the hormone levels between days 12 and 14 of the menstrual cycle?
There is a surge in levels of FSH and LH
-
What effects does the surge in LH levels have?
It causes ovulation to occur
-
What functions, other than ovulation, does LH have?
It causes the transformation of empty follicle cells into a corpus luteum which begins to produce progesterone and oestrogen
-
What happens to the hormone levels between days 15 and 21?
There is a rise in progesterone levels, peaking at day 21
-
What effects does progesterone have?
- It binds to specific receptor proteins on the cell membrane of endometrium cells which respond by maintaining a thick lining
- It inhibits the release of FSH and LH by the pituitary gland, another example of negative feedback
-
What happens if the egg is not fertilised?
- The corpus luteum degenerates and so progesterone is no longer produced
- This fall in progesterone levels causes the constriction of blood vessels in the uterus and the onset of menstruation at the end of the 28 day cycle
|
|