Hormones and the menstrual cycle

What is the corpus luteum?

a hormone-secreting structure that develops in an ovary after an ovum has been discharged but degenerates after a few days unless pregnancy has begun.

What causes ovulation?

a peak of LH hormone

What is progesterone?

a steroid hormone responsible for the decidualization of the endometrium (its development) and maintenance, respectively

The placenta takes over the role of the ____________ _____________.

corpus luteum

What is the follicle called once an egg is released?

corpus luteum

What is inside the ovaries?

hundreds of cells that could develop into mature eggs

What does this prevent form happening?

ovulation

What is this movement called?

ovulation

What is gestation?

the length of pregnancy

What happens whilst a follicle is growing?

the lining of the uterus has been thickens

What is menstruation?

the monthly bleeding where the lining of the uterus is shed

What does oestrogen do? (2 things)

1) Causes the lining of the uterus to build up. 2) Stimulates another hormone which leads the ovulation.

Which 4 hormones control the menstruation cycle?

1) Oestrogen 2) Progesterone 3) LH (Luteinising hormone) 4) FSH(Follicle Stimulating Hormone)

What happens if there is no fertilisation? (2 things)

1) The corpus luteum breaks down and stops making progesterone. 2) The lining of the uterus then passes out of the vagina

What are the four parts to the menstrual cycle?

1) menstruation 2) uterus lining builds up 3) ovulation 4) maintenance of uterus lining

What does progesterone do? (3 things)

1) signals the pituitary and hypothalamus glands in the brain to slow down the production of the hormones FSH and LH (which prevents additional follicles in the ovaries from developing and ovulating) 2) Maintains the lining of the uterus 3) Inhibits the release of further eggs (by stopping other hormones being produced)

What happens if pregnancy does not occur? (3 things)

1) the corpus luteum regresses (return to a less developed state) 2) the hormone levels of progesterone and estrogen go back down 3) the breakdown of the endometrium causes menstrual bleeding

What does progesterone prevent?(2 things)

1) the endometrium from being expelled 2) continues to prevent further ovulation

What are the two primary phases of the menstrual cycle?

1) the follicular phase 2) the luteal phase

how long will the corpus luteum last

10 to14 days and then die

How long does the average menstrual cycle last?

28 days

What happens in phase 4?

The wall is maintained for 14 days. If the egg is unfertilised then the lining breaks down and the cycle starts again.

What will the embryo start to form?

a very early placenta

Is progesterone most present before pr after ovulation?

after

What does FSH cause?

an egg to mature inside a follicle in the ovaries

Is oestrogen most present before pr after ovulation?

before

What does this hormone do? How?

completes the development of the uterine lining by thickening and maintaining it,

What is it essential for?

establishing and maintaining pregnancy in females

What many happen if sexual intercourse has taken place? Where?

fertilisation in the oviduct

If pregnancy does occur, what early pregnancy hormone will be released by the placenta?

hCG

Which hormone will a pregnancy test detect?

hCG

If you get pregnant, what is the first thing the embryo will do?

implants itself into the uterine lining

What is the endometrium?

inner lining of the uterus, richly supplied with blood vessels

What does the corpus luteum do if an egg is fertilised?

it carries on making progesterone

What happens to what is left over of the follicle?

it forms a structure in the ovary called the corpus luteum

What happens every month to one of these cells?

it grows inside a ball of cells called a follicle

What hormone makes this happen?

oestrogen

What is ovulation stimulated by?

oestrogen

What happens as a response to FSH?

oestrogen is secreted from the ovaries

What is LH hormone vital for?

ovulation and what happens just after ovulation.

What is the uterus?

part of the female reproductive system where the fertilised egg will implant

What does FSH stimulate the ovaries to do?

produce oestrogen

What does hCG signal the corpus luteum to continue secreting?

progesterone

What does the corpus luteum make?

progesterone

What is FSH also inhibited by?

progesterone

What is ovulation inhibited by?

progesterone

What does it secrete? and at what time in a pregnancy?

progesterone and oestrogen - during the early pregnancy

What does the corpus luteum release? Why?

progesterone to maintain the uterus lining

What will the placenta do later on in pregnancy?

secretes progesterone

The uterus lining will NOT ________ and menstruation will NOT ________________.

shed, happen

What happens to the endometrium if pregnancy DOESN'T occur?

sheds in a process known as menstruation

Define the menstrual phase

the 1st phase of the menstrual cycle when the menstruation occurs

Define the follicular phase

the 2nd phase of menstrual cycle where the uterine lining builds up and follicles ripen

Define the ovulation phase

the 3rd phase of the menstrual cycle when ovulation happens

Define the luteal phase

the 4th phase of the menstrual cycle where the uterus lining is maintained so that a fertilised egg can implant

What is implantation?

the attaching of the embryo to the wall of the uterus

What happens to the endometrium each month?

the endometrium thickens and renews itself, preparing for pregnancy

What happens to the folic in the middle of the menstrual cycle?

the follicle moves towards the edge of the ovary and the egg is released as the follicle bursts open

Which gland is this hormone secreted from?

the pituitary gland

What is oestrogen and progesterone produced by in the later stages of the pregnancy?

the placenta

What does this early placenta release?

the pregnancy hormone hCG

What is the menstrual cycle?

the regular natural change that occurs in the female reproductive system (specifically the uterus and ovaries) that makes pregnancy possible

What is ovulation?

the release of an egg from the ovary

What is an oviduct?

the tube linking the ovary with the uterus

What is the luteal phase?

this is post-ovulation when the body prepares the womb to accept a fertilized egg or embryo.

Why does the uterus form a lining?

to prepare for the fertilised egg to sink into it and develop into an embryo

Why does blood build up in the uterus?

to receive a fertilised egg (if there is one)

What is another job of oestrogen?

to slow down the production of FSH, while stimulating the secretion of LH

What is the follicular phase?

when a select number of follicles in the ovary mature until one releases an egg.

What happens in phase 1?

Menstruation Phase: The uterus lining breaks down for 4 days

Does the menstrual cycle have a beginning/ end?

No, the cycle is continuous, however the first day of menstruation is usually called day 1.

What happens in phase 3?

Ovulation: by this timea follicle has matured which releases an egg.

What happens in phase 2?

Phase 2: The uterus lining builds up again for 10 days.

What does oestrogen inhibit?

FSH

Which hormone causes this follicle to grow

FSH

What does progesterone inhibit the release of?

FSH and LH by the pituitary