Homoestasis

Question 1

What is homeostasis?

Answer 1

Keeping internal conditions stable in the body.

Question 2

Why is homeostasis important?

Answer 2

So that enzymes and cells work properly.

Question 3

What 3 things are controlled in homeostasis?

Answer 3

Body temperature, blood glucose level, and water level.

Question 4

What are the 3 parts of a control system?

Answer 4

Receptor, coordination centre, effector.

Question 4

What do effectors do?

Answer 4

Muscles or glands that carry out the response.

Question 5

What does a receptor do?

Answer 5

Detects changes (stimuli) in the environment.

Question 6

What is the job of a coordination centre?

Answer 6

Processes the information (e.g. brain, spinal cord, pancreas).

Question 7

What does the nervous system do?

Answer 7

Sends electrical messages quickly between body parts.

Question 8

What is a reflex?

Answer 8

A quick automatic response to danger, without thinking.

Question 8

What is a synapse?

Question 9

What is the path of a reflex arc?

Answer 9

Stimulus → receptor → sensory neurone → relay neurone → motor neurone → effector → response

Question 10

What is normal human body temperature?

Answer 10

About 37°C.

Question 11

What part of the brain controls temperature?

Answer 11

The thermoregulatory centre in the brain.

Question 12

What happens when you get too hot?

Answer 12

sweat is produced and blood vessels widen (vasodilation).

Question 13

What happens when you get too cold?

Answer 13

You shiver and blood vessels narrow (vasoconstriction).

Question 14

What organ controls blood glucose?

Question 14

What organ controls blood glucose?

Answer 14

The pancreas.

Question 15

What happens when blood glucose is too high?

Answer 15

Insulin is released, glucose moves into cells.

Question 16

What happens when blood glucose is too low?

Answer 16

Glucagon is released, glucose is released from the liver.

Question 17

What is insulin?

Answer 17

A hormone that lowers blood sugar by moving glucose into cells.

Question 18

What is glucagon?

Answer 18

A hormone that raises blood sugar by releasing glucose from the liver.

Question 19

What is Type 1 diabetes?

Answer 19

The pancreas makes no insulin – treated with insulin injections.

Question 20

What is Type 2 diabetes?

Answer 20

The body doesn’t respond to insulin – treated with diet and exercise.

Question 21

What is osmoregulation?

Answer 21

The control of water levels in the body.

Question 22

What organ controls water balance?

Answer 22

The kidneys.

Question 23

What hormone controls water reabsorption?

Answer 23

ADH (Anti-Diuretic Hormone).

Question 24

What happens if you drink lots of water?

Answer 24

More ADH is released, so you produce less urine.

Question 25

What does ADH do?

Answer 25

Makes kidneys reabsorb more water.

Question 26

What is excretion?

Answer 26

Removing waste products from the body. poo

Question 27

What are the 3 main waste products removed?

Answer 27

Carbon dioxide (lungs), urea (kidneys), excess water/salts (kidneys).

Question 28

What is urea and where is it made?

Answer 28

A waste product from breaking down proteins, made in the liver.

Question 29

How is urea removed?

Answer 29

Filtered by kidneys and passed out in urine.

Question 30

What are the problems with dialysis?

Answer 30

time-consuming, expensive, risk of infection.

Question 30

What is dialysis?

Answer 30

A machine that filters the blood when kidneys fail.

Question 31

What is a kidney transplant?

Answer 31

Replacing a damaged kidney with a healthy donor kidney.

Question 32

What are the pros of a kidney transplant?

Answer 32

Long-term solution, more freedom than dialysis.

Question 33

What are the cons of a kidney transplant?

Answer 33

Risk of rejection, need immunosuppressant drugs.

Question 34

what are the 3 control systems

Answer 34

Receptors- Detect a change Coordination centres- Link the brain or spinal cord Effectors- Muscle glands that respond

Question 35

what's vasodilation?

Answer 35

vasodilation is when blood vessles widen

Question 36

what is vasocontriction?

Answer 36

blood vessles narrow

Question 37

what's a reflex?

Answer 37

"A reflex is a quick, automatic response to danger." "A reflex is a fast, automatic response that helps protect the body from harm. It does not involve the conscious part of the brain

Question 38

⚡ Reflex Arc Pathway

Answer 38

Stimulus – e.g. something hot touches your skin Receptor – detects it (in your skin) Sensory neurone – carries message to spinal cord Relay neurone – in the spinal cord (part of CNS) Motor neurone – carries message to a muscle Effector – muscle moves (e.g. hand pulls away) Response – quick movement to protect you

Question 39

What part of the brain controls body temperature?

Answer 39

The hypothalamus

Question 40

What is vasodilation?

Answer 40

The widening of blood vessels near the skin to release heat when the body is too hot.

Question 41

❗ What Happens When Blood Glucose is Too Low?

Answer 41

Glucagon is released by the pancreas. Glucagon stimulates the liver to break down glycogen into glucose and release it into the blood.

Question 42

What hormone is released when blood glucose is too high?

Answer 42

Insulin.

Question 42

What hormone is released when blood glucose is too low?

Answer 42

Glucagon.

Question 43

What does insulin do?

Answer 43

It helps cells absorb glucose and stores glucose as glycogen in the liver.

Question 44

What does glucagon do?

Answer 44

It stimulates the liver to release glucose into the blood by breaking down glycogen.

Question 45

Where is insulin and glucagon produced?

Answer 45

In the pancreas.