B1.10/11 - Controlling body temperature/blood glucose levels

Question 1

What are the chemical reactions inside all the cells in our body controlled by?

Answer 1

They are controlled by enzymes

Question 2

Your cells will not function well if your body is…

Answer 2

• If your body is the wrong temperature
• If your body does not have the right amount of water
• If your body has too much carbon dioxide in the blood

Question 3

If your body is the wrong temperature, if your body does not have the right amount of water and if your body has too much carbon dioxide in the blood it does not function well. Why is this?

Answer 3

This is because if your body is under going any of these, the enzymes cannot work properly.

Question 4

What is homeostasis?

Answer 4

Homeostasis is the maintenance of a constant internal environment and to maintain this inputs and outputs need to be balanced in the body.

Question 5

What is the core body temperature of humans?

Answer 5

37 degrees Celsius, however this will be cooler at our feet and hands.

Question 6

Name two ways you can measure body temperature

Answer 6

-A clinical thermometer in the ear, mouth or anus.
-Temperature sensitive strips on the forehead.
Scientists can also use thermal imaging.

Question 7

Why is it dangerous if your body goes above 40 degrees Celsius?

Answer 7

Above 40 degrees Celsius you will get heat stroke and dehydration. Also enzymes cannot work properly.

Question 8

Why is it dangerous if your body goes below 35 degrees Celsius?

Answer 8

Below 35 degrees Celsius your body develops hypothermia. Also enzymes cannot work properly.

Question 9

How does your body lose and gain heat to keep the core temperature constant?

Answer 9

If your internal organs start to get too hot, the blood flowing through them carries away the excess heat. The increase temperature is monitored by the brain. The brain brings about the mechanisms to control temperature.

Question 10

How does the body gain heat in cold conditions?

Answer 10

• Respiration in cells releases some energy as heat
• Shivering (muscles contracting) generates heat
• Vasoconstriction (less blood flows near the skins surface)
• Wearing more clothes
• Exercise generates heat because muscles need to respire more to contract more

Question 11

How does the body lose heat in hot conditions?

Answer 11

• Vasodilation (more blood flows near the skins surface and gives off heat into the environment
• Sweating, the water in sweat evaporates taking heat from the skins surface into the environment.
• Wearing fewer clothes

Question 12

What is negative feedback?

Answer 12

Negative feedback is a mechanism in the body that keeps things at a steady level e.g body temperature

Question 13

What is a hormone?

Answer 13

A hormone is a chemical substance produced in the body and transported in tissue fluids such as blood to stimulate specific cells or tissues into action.

Question 14

What do hormones do?

Answer 14

• They are secretes from the glands into the bloodstream
• Travel in the blood to target organs
• Regulate the functions of many organs and cells
• Coordinate many processes in the body

Question 15

Why does the body react more slowly to hormones than to nerve impulses?

Answer 15

This is because hormones coordinate long-term changes such as growing up (maturing). Hormones also have to released from the cells they were made and then travel all over the body to reach their target organs. Nerve impulses travel directly to the effector via neurones.

Question 16

Name a type of hormone that acts quickly?

Answer 16

Adrenaline (this is produced when you are frightened)

Question 17

What hormone is made in the pancreas?

Answer 17

Insulin

Question 18

What does insulin do?

Answer 18

Insulin controls the amount of glucose (sugar) that is in the blood. The blood must have the right amount of glucose to deliver to all the cells. The cells can then get energy from the glucose.

Question 19

What happens if their is too much glucose in the body, in terms of insulin?

Answer 19

If there is too much glucose:

• The pancreas secretes insulin
• This travels to the liver via blood
• The insulin then makes the liver take up the extra energy, which is then converted into another carbohydrate (glycogen) and stored as glycogen. This is a way of storing energy.

Question 20

What happens if your pancreas does not make enough insulin and their is too much glucose in the blood?

Answer 20

If this occurs, you may get a disease called diabetes.

Question 21

How else can diabetes suffers control their glucose levels other than controlling what they eat and injecting themselves with insulin?

Answer 21

They can also exercise as excess glucose is converted into energy during exercise.