Module 5.1.2 - Homeostasis Flashcards
What is homeostasis?
Body maintaining a dynamic equilibrium, with small fluctuations over narrow range of conditions
What do receptors and effectors do for homeostasis?
- receptors and effectors are vital for body to maintain dynamic equilibrium
- receptors detect environmental change
- effectors create an appropriate response
What factors control homeostasis?
- blood glucose
- temperature
- water content
- pH
What is negative feedback?
- ideal conditions
- increase detected
- responses lower levels
- ideal conditions
- decrease detected
responses raise levels
What is positive feedback?
- conditions change
- change detected
- responses reinforce change
e.g. platelets clotting blood, labour contractions
What is thermoregulation?
Maintenance if a relatively constant core body temp to maintain optimum enzyme activity
What does ectotherm mean?
Core body temp is dependent on environment to warm body
‘outside heat’
What does endotherm mean?
Rely on metabolic processes to warm up, usually stable core body temp no matter the environment
‘inside heat’
What does behavioural responses mean?
Changes in an organisms activity in response to a stimulus
What does physiological responses mean?
Measurable reaction of the body to an internal or external stimulus
What physical processes cause heating up or cooling down?
Exothermic - chemical reactions
Latent heat - evaporation
Radiation - electromagnetic waves
Convection - heat travelling in liquids
Conduction - heat travelling in solids
Why is it good that many ectotherms live in water?
Don’t need to thermoregulate because of high heat capacity of water
Why can ectotherms live in difficult habitats with limited food?
Require less food due to requiring less energy to regulate temp
- are more vulnerable to fluctuations in environment
