Menstrual cycle Flashcards
Name 4 hormones involved in the menstrual cycle
FSH, LH, oestrogen and progesterone
What two hormones does the piturity gland secrete
FSH and LH
what hormones does the ovaries produce
Oestrogen and progesterone
What is the role of FSH
Stimulates the development of follicles in the ovaries, which contain eggs , and stimulates the follicles to produce oestrogen
What is the role of LH
Causes ovulation to occur at day 14, and stimulates the ovary to produce progesterone from the corpus luteum
What is the role of Oestrogen
The role of Oestrogen is to rebuild the lining of the uterus and stimulate the release of LH
What is the role of Progesterone
To maintain the thick lining of the Uterus in preparation for the fertilized egg and inhibits the production of FSH
When does the menstrual cycle begin
At day 1 when the lining of the uterus is shed
What happens from day 1
The piturity gland secretes FSH into the blood plasma, which travels to the ovaries to stimulate follicles to grow.
What do the growing follicles do
secrete small amounts of Oestrogen, causing the uterus lining to start to build up again and inhibit the production of FSH and LH, as follicles grow more they secrete more oestrogen up until the critical point (day 10) when the piturity gland will release more FSH and LH
What does a surge in LH do
A surge in LH causes one of the follicles to release an egg, this is called ovulation and occurs at around day 14
What happens after ovulation
The LH causes the empty follicle to turn into a corpus Luteum, which secretes small amounts of progesterone
What does the secreted progesterone do
The progesterone will maintain the lining of the uterus and inhibit the production of FSH and LH
What happens if the egg is not fertilised
The corpus Luteum will disintegrate and no longer produce progesterone since there is less progesterone FSH is no longer inhibited so uterus lining breaks down and cycle repeats itself
