Homeostasis 1

Question 1

Tissues

Answer 1

Groups of cells that share the same characteristics or specialisations

Question 2

Organs

Answer 2

Collections of tissues, usually of several different types, that synchronise to perform a particular function

Question 3

What is the equation of life?

Answer 3

Nutrients +O2 =Energy (ATP) + CO2 + Wastes

Question 4

Homeostasis

Answer 4

Preventing disturbance in the system to maintain an optimum internal environment

Question 5

What does homeostasis require?

Answer 5

Integration of organ systems

Regulation at cell, tissue and system level

Question 6

What does homeostasis mean?

Answer 6

Similar condition

Question 7

What does homeostasis aim to do?

Answer 7

Maintain a constant internal environment

Question 8

What are examples of homeostasis in action?

Answer 8

Cooling down when hot

Heating up when cold

Question 9

What are 3 common everyday challenges to our internal environment?

Answer 9

External temperatures

Diet

Exercise

Question 10

What do external temperatures, diet and exercise impact on?

Answer 10

Body fluid composition

Energy stores

Body temperature

Question 11

What happens to homeostasis at extremes?

Answer 11

It becomes less effective

Question 12

How is the regulation of tissues and organ systems in order to minimise change brought about?

Answer 12

Through negative feedback control

Question 13

What is the mechanism of negative feedback control?

Answer 13

• Receptor senses change (stimulus)
• Information sent to integrating centre
• Compared to reference level
• Signal generated and sent to effector
• Response produced

Question 14

What is the magnitude of the generated signal in proportion to?

Answer 14

The magnitude of difference from normal and the magnitude of response

Question 15

What is the aim of negative feedback control?

Answer 15

To restore the internal environment to optimal conditions

Question 16

What can homeotherms do?

Answer 16

Maintain a constant temperature over a wide range of external temperatures

Question 17

What are the characteristics of negative feedback systems?

Answer 17

• There is oscillation around the set point

- Restore the regulated variable after its initial displacement but cannot prevent it happening.

Question 18

What happens in feed forward control?

Answer 18

Additional receptors permit system to anticipate change and therefore activate response earlier

Question 19

What is an example of feed forward control?

Answer 19

Temperature receptors in our skin detect external temperature and activate response before any significant change in core temperature occurs

Question 20

What doe positive feedback do?

Answer 20

An initial disturbance sets off a chain of events that lead to an even greater disturbance

Question 21

What does positive feedback control lead to?

Answer 21

Instability

Question 22

When does positive feedback control occur?

Answer 22

In the nerve action potential

Ovulation

Question 23

What occurs during positive feedback control?

Answer 23

Self Amplification

Question 24

What happens when the muscle and liver cells are unable to take up glucose from the blood in diabetes?

Answer 24

The body thinks it is starving. In response the liver releases glucose from its stores which increases the already high blood glucose levels

Question 25

What does diabetes associated hyperglycaemia cause?

Answer 25

Loss of salt and H2O and acid/base disturbances

Blindness

Neural dysfunction

Kidney damage

Question 26

How is the integration of systems coordinated?

Answer 26

Endocrine and nervous systems

Question 27

What are homeostatic mechanisms represented by?

Answer 27

Reflexes

Question 28

What can reflexes be/

Answer 28

Neural and/or hormonal

Simple or complex

Question 29

How much of our body weight is made up of water?

Answer 29

60%

Question 30

What processes are regulated in order to maintain H2O balance?

Answer 30

Input: thirst mechanism

Output: regulation of urinary losses