(Paper 2) 5.2 Homeostasis: The Endocrine System

Question 1

What is a hormone?

Answer 1

A chemical substance produced by a gland, carried in the blood, that alters the activity of specific target organs.

Question 2

Where are hormones destroyed after use?

Answer 2

In the liver.

Question 3

How do the effects of hormones differ from nerves?

Answer 3

Hormonal responses are slower but last longer than nerve responses.

Question 4

What is considered the ‘master gland’ and why is it called that?

Answer 4

The pituitary gland; it controls other glands by releasing hormones that trigger other hormone releases.

Question 5

What hormone controls water content in the blood, and where is it secreted from?

Answer 5

ADH (Anti-Diuretic Hormone) from the pituitary gland.

Question 6

What are the effects of ADH?

Answer 6

It increases water reabsorption by the kidney’s collecting ducts.

Question 7

What hormone prepares the body for ‘fight or flight’?

Answer 7

Adrenaline from the adrenal glands.

Question 8

What are the effects of adrenaline?

Answer 8

Increases heart rate, breathing rate, blood flow to muscles, and glycogen to glucose conversion.

Question 9

What hormone controls blood glucose levels?

Answer 9

Insulin, released by the pancreas.

Question 10

What does insulin do?

Answer 10

It increases the conversion of glucose to glycogen for storage in the liver.

Question 11

What non-communicable disease is the result of a person being insulin resistant?

Answer 11

Diabetes

Question 12

Compare nervous and hormonal control in terms of signal type, speed, and duration.

Answer 12

Nervous: electrical (very rapid, short-lived)

Hormonal: chemical (slower, long-lasting)

Question 13

What is a negative feedback mechanism?

Answer 13

A process that detects changes from a set point and triggers responses to return conditions to normal.

Question 14

What happens in negative feedback if a level rises above the set point?

Answer 14

The control system reduces the level back to normal.

Question 15

What happens in negative feedback if a level falls below the set point?

Answer 15

The control system increases the level back to normal.

Question 16

What are the general stages in a negative feedback loop?

Answer 16

Condition changes from set point

Change is detected

Corrective mechanism activated

Condition returns to set point

Mechanism switched off

Question 17

What part of the brain controls body temperature?

Answer 17

The hypothalamus.

Question 18

Give two responses your body makes when it is too hot.

Answer 18

Sweating and vasodilation (blood vessels widen).

Question 19

Give two responses your body makes when it is too cold.

Answer 19

Shivering and vasoconstriction (blood vessels narrow).

Question 20

What gland produces thyroxine?

Answer 20

The thyroid gland.

Question 21

What is the function of thyroxine?

Answer 21

It stimulates the basal metabolic rate and plays a role in growth and development.

Question 22

How is thyroxine controlled in the body?

Answer 22

By negative feedback.

Question 23

What happens when thyroxine levels are too low?

Answer 23

The hypothalamus releases TRH

The pituitary gland releases TSH

The thyroid produces more thyroxine

Question 24

What happens when thyroxine levels are normal?

Answer 24

TRH release from the hypothalamus is inhibited

TSH release from the pituitary is reduced

Thyroxine production stays steady

Question 25

What gland produces adrenaline?

Answer 25

The adrenal glands.

Question 26

When is adrenaline released?

Answer 26

During times of fear or stress.

Question 27

What does adrenaline do to the body?

Answer 27

Increases heart rate and breathing rate Converts glycogen to glucose Diverts blood to muscles from non-essential organs

Question 28

Is adrenaline controlled by negative feedback?

Answer 28

No, adrenaline is not regulated by negative feedback.

Question 29

Why is glucose needed by cells?

Answer 29

For respiration to release energy.

Question 30

What hormone regulates blood glucose levels?

Answer 30

Insulin

Question 31

Where is insulin produced?

Answer 31

In the pancreas

Question 32

What cells in the pancreas produce insulin

Answer 32

Pancreatic beta cells

Question 33

What happens when blood glucose levels are too high?

Answer 33

The pancreas secretes insulin Glucose moves from the blood into cells Liver and muscles convert excess glucose into glycogen for storage

Question 34

What happens when blood glucose levels are too low?

Answer 34

The pancreas does not secrete insulin The liver does not convert glucose into glycogen Blood glucose level increases

Question 35

What is diabetes?

Answer 35

A condition where blood glucose levels remain too high.

Question 36

How is diabetes treated in general?

Answer 36

With insulin injections, which help convert glucose into glycogen, lowering blood glucose levels.

Question 37

What causes Type 1 diabetes?

Answer 37

The pancreas fails to produce enough insulin.

Question 38

How is Type 1 diabetes managed?

Answer 38

Insulin injections Monitoring blood glucose Controlled diet Regular exercise

Question 39

What causes Type 2 diabetes?

Answer 39

Body cells no longer respond to insulin.

Question 40

Who is most likely to develop Type 2 diabetes?

Answer 40

Older individuals, especially those with obesity.

Question 41

How is Type 2 diabetes managed?

Answer 41

Carbohydrate-controlled diet Exercise regime

Question 42

What is glucagon?

Answer 42

A hormone produced by the pancreas that raises blood glucose levels.

Question 43

When is glucagon released?

Answer 43

When blood glucose levels are too low.

Question 44

How does glucagon affect the liver?

Answer 44

It causes the liver to convert stored glycogen back into glucose, which is released into the blood.

Question 45

What is the role of insulin in blood sugar control?

Answer 45

Insulin causes glucose to move into cells and be stored as glycogen, lowering blood glucose.

Question 46

What is the role of glucagon in blood sugar control?

Answer 46

Glucagon causes glycogen to be converted to glucose, increasing blood glucose.

Question 47

What type of control system is the interaction of insulin and glucagon an example of?

Answer 47

Negative feedback

Question 48

What is puberty?

Answer 48

The stage when a child's body develops into an adult's body, usually between ages 10 and 16.

Question 49

What causes the changes that occur during puberty?

Answer 49

Hormones – chemical messengers produced by glands.

Question 50

What hormone is responsible for puberty in males?

Answer 50

Testosterone, produced by the testes.

Question 51

What does testosterone do during puberty?

Answer 51

It controls the development of male secondary sexual characteristics.

Question 52

What hormone is responsible for puberty in females?

Answer 52

Oestrogen, produced by the ovaries.

Question 53

What does oestrogen do during puberty?

Answer 53

It controls the development of female secondary sexual characteristics.

Question 54

Name three secondary sexual characteristics that develop in both boys and girls during puberty.

Answer 54

Growth of pubic hair, underarm hair, and development of sexual organs.

Question 55

Name three puberty changes in boys only.

Answer 55

Voice breaks, facial/body hair growth, and muscle development.

Question 56

Name three puberty changes in girls only.

Answer 56

Breast development, hips widen, and menstruation begins.