Flashcards in Control Of The Oestrus Cycle Deck (13):
What is the role of FSH?
It stimulates the development of follicles in the ovary, which contain eggs and stimulates the follicles in the ovaries to produce oestrogen
What is the role of LH?
It causes ovulation to occur, and stimulates the ovary to produce progesterone from the corpus luteum
What two hormones are produced by the ovaries?
Oestrogen and progesterone
What is the role of oestrogen?
It causes the rebuilding of the uterus lining after menstruation and stimulates the pituitary gland to produce LH
What is the role of progesterone?
It maintains the lining of the uterus in readiness to receive the fertilised egg and inhibits the production of FSH from the pituitary gland
What occurs during days 1-7?
The uterus lining breaks down and menstruation occurs
What occurs during days 8-11?
The lining of the womb thickens in preparation for the egg
What occurs in days 12-17?
What occurs during days 18-25?
If fertilisation has not taken place, the corpus luteum fades away
What occurs during days 26-28?
The uterine lining detaches, leading to menstruation
Give an example of negative feedback in the menstrual cycle
The pituitary gland secretes FSH which causes ovary follicles to secrete oestrogen. This release of oestrogen causes the re-growth of the uterus wall but also inhibits further secretion of FSH
Give an example of positive feedback in the menstrual cycle
The pituitary gland secretes LH and FSH which causes the ovary follicles to secrete more oestrogen. This causes ovulation but also stimulates further FSH secretion