Homeostasis- Basics Flashcards
What is homeostasis?
The maintenance of a stable internal environment
What can changes in the external environment do?
Affect your internal environment- the blood and tissue fluid that surrounds cells
What does homeostasis involve?
Control systems that keep the internal environment roughly constant
Why is keeping the internal environment stable vital?
So that cells can function normally and stop them from being damaged
Why is it particularly important to maintain the right core body temperature and blood pH?
Temperature and pH affect enzyme activity and enzymes control the rate of metabolic reactions
Why is it important to maintain the right concentration of glucose in the blood?
Because cells need glucose for energy and blood glucose concentration also affects the water potential of blood
What do homeostatic systems involve?
Receptors, a communication system and effectors
What happens when receptors detects when a level is too high or too low?
The information is communicated via the nervous system or the hormonal system to effectors
How do effectors respond in negative feedback?
To counteract the change and bring the level back to normal
What is a negative feedback mechanism?
The mechanism that restores the level to normal
What is the purpose of negative feedback?
To keep things around the normal level
How does negative feedback only work within certain limits?
If the change is too big then the effectors may not be able to counteract
Why does homeostasis involve multiple negative feedback mechanisms for each thing being controlled?
Having more than one mechanism gives more control over changes in your internal environment, and means you can actively increase or decrease a level so it returns to normal
What does a positive feedback mechanism do?
Amplifies the change
How do effectors respond in positive feedback?
To further increase the level away from the normal level
