Feedback mechanisms

Question 1

What does hormone LH do

Answer 1

stimulates ovulation

causes corpus luteum to be developed

Question 2

what does FSH stand for

Answer 2

follicle-stimulating hormone

Question 3

what does hormone FSH do

Answer 3

stimulates development of follicles in ovaries

stimulates follicle to produce oestrogen

Question 4

what does hormone oestrogen do

Answer 4

causes uterus lining to rebuild

stimulates pituitary gland to produce LH

Question 5

where is LH produced

Answer 5

pituitary gland

Question 6

what does hormone progesterone do

Answer 6

maintains thick lining in uterus for fertilised egg

inhibits FSH production in pituitary gland

Question 7

describe the menstrual cycle in terms of the hormones

Answer 7

FSH released
oestrogen produced as follicles grow
oestrogen increases then critical point reached
pituitary gland releases more FSH and LH (positive feedback)
surge in LH causes a follicle to release an egg
after ovulation, LH causes empty follicle to develop into corpus luteum
corpus luteum secrets progesterone

Question 8

what does each follicle contain

Answer 8

an egg

Question 9

If an egg isn’t fertilised, what happens in terms of hormones in the menstrual cycle

Answer 9

progesterone stops being produced
lining isn't maintained
lining breaks down
FSH no longer inhibited
FSH released so menstrual cycle continues

Question 10

What happens in negative feedback

Answer 10

Feedback causes the measures to be turned off

System return to its original (normal) level

Question 11

What happens in positive feedback

Answer 11

Feedback causes the measures to remain turned on

So system deviates even more from original (normal) levels