Homeostasis Basics Flashcards
Define homeostasis
Physiological control systems that maintain the internal environment within restricted limits
Why does the internal environment need to be kept stable
For cells to function normally and stop damage
And not reduce enzyme activity
What happens if the body temp is too high
Enzymes denature = vibrate too much breaking H bonds of tertiary structure changing shape of active site
Metabolic reactions are less efficient
What happens if the body temp is too low
Enzyme activity reduced
Slow rate of metabolic reactions
What happens if the ph isn’t optimum
Enzymes denature
Metabolic reactions are less efficient
What detects when a level is too high/low
Receptors
How is info communicated
Nervous or hormonal system
What do effectors do
counteracts the change and brings it back to normal
What is a negative feedback system
Restores level back to normal
When do negative feedback systems no longer work
If the change is too big for effectors to be able to counteract it
Why does the body have multiple negative feedback systems
Gives more control over changes
Actively increasing or decreasing levels (control over both directions) so faster response
What is a positive feedback system
Amplifies change away from the normal level
Explain the positive feedback system at blood clots
Platelets are activated
Release chemical to activate more platelets
Injury quickly clotted
When it’s formed a negative feedback system takes over
Explain a positive feedback system with hypothermia
Body temp decreases
Brain function decreases
Shivering stops
Body temp falls even more
Why is positive feedback not used in homeostasis
Doesn’t keep internal environment stable but away from the normal
