Homeostasis & Negative Feedback Control

Question 1

What forms the internal environment of the body?

Answer 1

• tissue fluid and blood
• (which are extracellular fluids)

Question 2

What needs to happen for cells to function properly?

Answer 2

• the optimal levels of many factors in the internal environment must remain constant

Question 3

What is homeostasis?

Answer 3

• the process of maintaining the internal environment in a constant optimal state, despite constant changes in the external environment

Question 4

How is homeostasis maintained?

Answer 4

• the body detects any change from the set point or norm of the internal environment and then corrects this change or deviation

Question 5

What is negative feedback?

Answer 5

• a control mechanism whereby a change from the set point of any factor is corrected by bringing about a change in the opposite direction

Question 6

What is a negative feedback system made up of?

Answer 6

• a receptor
• a control centre
• an effector

Question 7

What does a receptor do in a negative feedback system?

Answer 7

• detects a change (deviation) from the set point
• sends information to the control centre (usually the brain)

Question 8

What does a control centre do in a negative feedback system?

Answer 8

• processes the information from the receptor
• and activates corrective mechanisms that it sends to the effector

Question 9

What does an effector do in a negative feedback system?

Answer 9

• responds and corrects the change
• returning conditions to the set point