Homeostasis and Hormones

Question 1

What are hormones?

Answer 1

Chemicals that target certain organs which create a specific response.

Question 2

What are hormones produced by?

Answer 2

Endocrine glands.

Question 3

How do hormones travel to their target organs?

Answer 3

They travel through the blood.

Question 4

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

Answer 4

They are both produced in the hypothalamus in the brain.

-They target the pituitary gland.

Question 5

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

Answer 5

They are all produced in the pituitary gland.

• FSH and LH targets the ovaries
• ADH targets the kidney
• TSH targets the thyroid gland

Question 6

Where is adrenalin produced and what organs does it target?

Answer 6

It is produced in the adrenal gland.

- It targets various organs like the heart, liver, and skin etc.

Question 7

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

Answer 7

They are both produced in the ovaries.

• Oestrogen targets the ovaries, uterus, and pituitary gland
• Progesterone targets the uterus

Question 8

Where is testosterone produced and what organs does it target?

Answer 8

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

Question 9

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

Answer 9

They are both produced in the pancreas.

They both target the liver, and muscle and adipose tissue.

Question 10

Where is thyroxine produced and what organs does it target?

Answer 10

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

Question 11

What is negative feedback?

Answer 11

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

Question 12

What response is adrenalin responsible for?

Answer 12

The ‘fight or flight’ response.

Question 13

How does adrenalin affect your body?

Answer 13

• 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

Question 14

How does thyroxine affect your body?

Answer 14

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

Question 15

Which hormones control the menstrual cycle?

Answer 15

• Oestrogen
• Progesterone
• FSH
• LH

Question 16

What is menstruation?

Answer 16

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.

Question 17

What happens during the second week of the menstrual cycle?

Answer 17

The uterus lining gradually builds up.

Question 18

What is ovulation?

Answer 18

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

Question 19

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

Answer 19

From around day 14 to 16.

Question 20

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

Answer 20

The uterus lining continues to build up.

Question 21

What happens if fertilisation occurs?

Answer 21

The uterus lining is maintained and menstruation does not occur.

Question 22

What happens if fertilisation does not occur?

Answer 22

Menstruation occurs and the menstrual cycle repeats.

Question 23

What is contraception?

Answer 23

A way to prevent fertilisation.

Question 24

How does hormonal contraception work and what are some examples?

Answer 24

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

Question 25

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

Answer 25

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

Question 26

What are the levels of progesterone and oestrogen during menstruation?

Answer 26

``` Progesterone = low Oestrogen = high ```

Question 27

What do high levels of oestrogen stimulate?

Answer 27

The release of LH.

Question 28

What do low levels of progesterone stimulate?

Answer 28

The release of FSH

Question 29

What does FSH do?

Answer 29

It stimulates the growth and maturation of follicles.

Question 30

What does LH do?

Answer 30

Trigger ovulation.

Question 31

What do maturing follicles stimulate?

Answer 31

A rise in oestrogen levels.

Question 32

What happens to progesterone levels when the egg is released?

Answer 32

Progesterone levels experience a sudden increase.

Question 33

What does oestrogen do?

Answer 33

Builds the uterus wall.

Question 34

What does progesterone do?

Answer 34

Maintains the uterus wall.

Question 35

What do increases in oestrogen and progesterone do?

Answer 35

Cause thickening in the uterus wall.

Question 36

What does a decrease in oestrogen and progesterone stimulate?

Answer 36

It triggers menstruation.

Question 37

What is clomifene?

Answer 37

A fertility drug that causes an increase in FSH and LH.

Question 38

What is IVF (In-vitro fertilisation)?

Answer 38

Fertilisation outside a woman's body. | - This is offered to people who struggle conceiving.

Question 39

What is the definition of Homeostasis?

Answer 39

Maintaining conditions inside the body at a constant level.

Question 40

What is osmoregulation?

Answer 40

It controls how much water is lost in urine and the amount of water in the body.

Question 41

What is thermoregulation?

Answer 41

It keeps core body temperature steady at around 37°C. | - It is controlled by the hypothalamus which triggers changes in the skin and muscles.

Question 42

What changes occur in the body when it is too hot?

Answer 42

- Blood vessels near the skin will dilate to flow more blood near the skin. - Sweat glands release more sweat onto the skin surface to evaporate. - Sebaceous glands produce oil that helps sweat to spread out over the skin. - All of this increases transfer of energy (heat) into the surroundings.

Question 43

What changes occur in the body when it is too cold?

Answer 43

- Blood vessels near the skin will constrict to reduce the flow of blood near the skin. - Sweat glands stop producing sweat. - Body hairs are raised by erector muscles in skin. - Shivering - All of this reduces the transfer of energy (heat) into the surroundings.

Question 44

What is vasoconstriction?

Answer 44

Blood vessels constrict to restrict the amount of blood flow. - Less in surface capillaries and more in deep skin vessels.

Question 45

What is vasodilation?

Answer 45

Blood vessels dilate to increase the amount of blood flow. | - Less in deep skin vessels and more in surface capillaries.

Question 46

What happens in the pancreas when the blood glucose levels are too high?

Answer 46

- Pancreas detects rise in blood glucose concentration. - Pancreas increases the amount of insulin and decreases the amount of glucagon. - Increased insulin causes muscles and liver cells to remove glucose from blood and store it as glycogen. - Blood glucose concentration decreases.

Question 47

What happens in the pancreas when the blood glucose levels are too low?

Answer 47

- Pancreas detects fall in blood glucose concentration. - Pancreas decreases the amount of insulin and increases the amount of glucagon. - Increased glucagon causes liver cells to convert stored glycogen into glucose and release it into the blood. - Blood glucose concentration increases.