B1.2 Responses To A Changing Environment

Question 1

What affect can too much water have on the body?

Answer 1

It can cause swellings and high blood pressure.

Question 2

What is the term used to describe the process of keeping the internal environment stable?

Answer 2

Homeostasis.

Question 3

What is sweat produced by?

Answer 3

Sweat glands.

Question 4

What is a gland?

Answer 4

A part of the body that makes substances and then releases them.

Question 5

What is the control of water in the body called?

Answer 5

Osmoregulation.

Question 6

What is blood glucose regulation?

Answer 6

The control of the amount of glucose in the blood, it’s a crucial process as if the glucose concentration is too high/low you can become very ill.

Question 7

What is the control of body temperature called?

Answer 7

Thermoregulation.

Question 8

What is the hypothalamus?
What does it do?
How does it receive information?

Answer 8

It is a small part of the brain that constantly monitors temperature.
The hypothalamus receives information from nerve endings in the dermis of the skin about the temperature of the body. The hypothalamus also receives information about temperature from the blood.

Question 9

What does the hypothalamus cause the muscles to do if the body temperature falls below 37 degrees?

Answer 9

The hypothalamus causes muscles to shiver, which release heat to warm the body up. It also reduces blood flow near the skin so that less heat is lost to the air.

Question 10

How do the erector muscles in the skin help to preserve heat?

Answer 10

The hypothalamus cause the muscles to contract, causing the body hairs to stand upright. In humans this has little effect, but it is very useful in other animals.

Question 11

How do the subaceous glands help to keep the skin in good condition?

Answer 11

They release oils to lubricate the skin ( at the bases of the hair) and keep it in good condition.

Question 12

What does the hypothalamus do when the temperature exceeds 37 degrees?

Answer 12

Sweat is produced, and as it evaporates heat is transferred from the skin to the surroundings, cooling down the skin. Blood flow is also increased near the skin so that more heat is lost, causing the skin to look pinker.

Question 13

What is vasoconstriction? Why does it take place?

What is vasodilation?

Answer 13

When it is cold, blood flow near to the skin reduces by narrowing the blood vessels closest to the surface.
The opposite process is called vasodilation and occurs when the body is too hot.

Question 14

What is the control of the body temperature an example?

Answer 14

Negative feedback.

Question 15

What do sense organs do?

Answer 15

They detect changes, both inside and outside of the body, a stimulus.

Question 16

What is the internal environment?

Answer 16

The conditions inside the body, they must remain stable e.g the correct amount of water to allow substances to dissolve and reactions to occur.

Question 17

What are impulses?

Answer 17

Electrical signals created by the receptor cells that travel to the brain with information.

Question 18

What do electrical impulses travel along?

Answer 18

Neurones.

Question 19

What is the travelling/transmission of impulses called?

Answer 19

Neurotransmission.

Question 20

What is a dendron?

Answer 20

Extension of a neurone that carries the impulse to the cell body. It ends in many dendrites and is usually shorter than an axon.

Question 21

What makes up the central nervous system?

Answer 21

The spinal cord and the brain, which process and control the transmission of electrical impulses.

Question 22

What are effectors?

Answer 22

Muscles and glands which carry out actions (response) based on the impulses sent.