Homeostasis and Hormones Flashcards Preview

GCSE Edexcel Biology - PAPER 2 > Homeostasis and Hormones > Flashcards

Flashcards in Homeostasis and Hormones Deck (47)
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What are hormones?

Chemicals that target certain organs which create a specific response.


What are hormones produced by?

Endocrine glands.


How do hormones travel to their target organs?

They travel through the blood.


Where are TRH and CRH produced and what is its target organ?

They are both produced in the hypothalamus in the brain.
-They target the pituitary gland.


Where are TSH, ADH, FSH, and LH produced and what are their target organs?

They are all produced in the pituitary gland.
- FSH and LH targets the ovaries
- ADH targets the kidney
- TSH targets the thyroid gland


Where is adrenalin produced and what organs does it target?

It is produced in the adrenal gland.
- It targets various organs like the heart, liver, and skin etc.


Where are oestrogen and progesterone produced and which organs do they target?

They are both produced in the ovaries.
- Oestrogen targets the ovaries, uterus, and pituitary gland
- Progesterone targets the uterus


Where is testosterone produced and what organs does it target?

It is produced in the testis and it targets the male reproductive system.


Where are insulin and glucagon produced and what are their target organs?

They are both produced in the pancreas.
They both target the liver, and muscle and adipose tissue.


Where is thyroxine produced and what organs does it target?

It is produced in the thyroid gland and targets the digestive system, the heart, the brain and bones (it is important for good health).


What is negative feedback?

When a change from the normal level (higher or lower) brings about more changes to restore it to the normal level.


What response is adrenalin responsible for?

The 'fight or flight' response.


How does adrenalin affect your body?

- It increases heart rate
- Dilates blood vessels that take blood to the muscles
- Constrict blood vessels that aren't going to vital organs.
- Causes the liver to convert glycogen into glucose


How does thyroxine affect your body?

- It controls your metabolic rate, which is the rate at which cells respire.


Which hormones control the menstrual cycle?

- Oestrogen
- Progesterone
- LH


What is menstruation?

It is the break down of the uterus lining after the egg that has been released is not fertilised. This lasts from day 1 for about 5 days.


What happens during the second week of the menstrual cycle?

The uterus lining gradually builds up.


What is ovulation?

On around day 14, an egg is released from an ovary.


Between which days in the menstrual cycle is fertilisation most likely to take place?

From around day 14 to 16.


What happens during most of week 3 and week 4 of the menstrual cycle?

The uterus lining continues to build up.


What happens if fertilisation occurs?

The uterus lining is maintained and menstruation does not occur.


What happens if fertilisation does not occur?

Menstruation occurs and the menstrual cycle repeats.


What is contraception?

A way to prevent fertilisation.


How does hormonal contraception work and what are some examples?

It works by releasing hormones to prevent ovulation and thicken the mucus at the cervix to prevent sperm from passing.
It includes:
- hormone pills
- hormone implants
- hormone injections


How do barrier methods of contraception work and what are some examples?

Barrier methods prevent sperm from reaching the egg with a physical barrier.
These include:
- condoms (male and female)
- the diaphragm
- caps
- sponges


What are the levels of progesterone and oestrogen during menstruation?

Progesterone = low
Oestrogen = high


What do high levels of oestrogen stimulate?

The release of LH.


What do low levels of progesterone stimulate?

The release of FSH


What does FSH do?

It stimulates the growth and maturation of follicles.


What does LH do?

Trigger ovulation.