Control Of The Menstrual Cycle

Front 1

what is a follicle and where does it develop

Back 1

an egg and its surrounding protective cells

-it develops in the ovary

Front 2

what is ovulation

Back 2

an egg being released

Front 3

what happens if theres no fertilisation

Back 3

the uterus lining breaks down and leaves the body through the vagina

Front 4

what are the four hormones that the menstrual cycle is controlled by

Back 4

follicle stimulating hormone

luteinising hormone

oestrogen

progesterone

Front 5

what does fsh do

Back 5

it stimulates the follicles to develop

Front 6

what does LH do

Back 6

it stimulates ovulation and stimulates the corpus luteum to develop

Front 7

what does oestrogen do

Back 7

it stimulates the uterus lining to thicken

Front 8

what does progesterone do

Back 8

maintains the tick uterus lining ready for implantation of an embryo.

Front 9

what gland secretes fsh and LH

Back 9

the anterior pituitary gland

Front 10

what secretes oestrogen and progesterone

Back 10

the ovaries

Front 11

what happens during highFSH concentration in the blood

Back 11

-FSH stimulates follicle development

- the follicle releases oestrogen

-fsh stimulates the ovaries to release oestrogen

Front 12

what happens during rising concentrations of oestrogen

Back 12

oestrogen stimulstes the uterus lining to thicken

-oestrogen inhibits FSH being released from the pituitary gland

Front 13

what happens when oestrogen concentration peaks

Back 13

REALLY high oestrogen concentration stimulates the pituitary gland to release LH and FSH

Front 14

what happens when the levels of LH increase (surge)

Back 14

ovulation starts - the follicle ruptures and the egg is released

-LH stimulates the ruptured follicle to turn into a corpus luteum

-the corpus luteum releases progesterone

Front 15

what happens during rising concentrations of progesterone

Back 15

progesterone inhibitis FSH and LH release from pituitary

-the uterus lining is maintained by progesterone

-if no embryo implants the corpus luteum breaks down and stops releasing progesterone

Front 16

what happens when the levels of progesterone start falling

Back 16

FSH and LH concentrations increase because they're no longer being inhibited by progesterone

-the uterus lining isn't maintained so it breaks down - menstruation happens and the cycle starts again .

Front 17

describe the negative feedback loop that uses FSH

Back 17

-FSH stimulates the ovary to release oestrogen

-oestrogen inhibits further release of FSH

- after FSH has stimulated follicle of development negative feed back keeps the FSH concentration low = makes sure that no more follicle develop.

Front 18

describe the negative feedback loop that uses LH

Back 18

LH stimulates the corpus luteum to develop which produces progesterone.

-progesterone further inhibits further release of LH

-negative feed back makessure that no more follicles develop when the corpus luteum is developing

-it also makes sure the uterus lining isn't maintained if no embryo plants

Front 19

describe the positive feedback loop in the menstrual cycle

Back 19

oestrogen stimulates the anterior pituitary to release LH

-LH stimulates the ovary to release more oestrogen

-oestrogen further stimulates the anterior pituitary to release LH

-high oestrogen concentration triggers positive feedback to make ovulation happen.