5.1 Communication And Homeostasis Flashcards
What is the definition of homeostasis?
Act of keeping conditions internally stable
What do good communication systems consist of?
-1. Covers whole body
2. Allows cells to communicate
3. Allows specific communication
4. Allows rapid communication
5. Enables short and long term responses
What is the definition of negative feedback?
Change to internal environment is detected so change is signalled to cells and a response occurs
What is the definition of positive feedback?
Increases the original change which destabilises the system
E.g. while in labour
What are ectotherms?
Animals that use their surroundings to warm their bodies so their core temperature is dependent on their environment
What are the advantages of being ectothermic?
- Less energy required
- Less food in respiration
- Can survive longer without food
What are the disadvantages of being ectothermic?
- Not sustainable in cold conditions
- Not capable of activity in winter months
- Metabolic reactions are slower
What point must you include in a question about temperature regulation of ectotherms?
Mention surface area/radiation
What is the definition of an endotherm?
Animals that rely on metabolic processes to warm their bodies and maintain their core temperature
What are the advantages of being endothermic?
- Body temperature is easier to maintain and constant in cooler environments
- Capable of activity throughout the year
- Can inhabit colder parts of the planet
What are the disadvantages of being endothermic?
- More energy to maintain
- Need to eat more
- Less energy used in growth
What part of the brain detects changes in body temperature?
Thermoregulatory centre in Hypothalamus
What are peripheral temperature receptors?
Skin receptors monitor changes in skin temperature
‘Early warning system’
What happens in vasoconstriction?
Arteriole is constricted and less blood to surface
Sphincter is contracted
Shunt vessels in use
What happens in vasodilation?
Arteriole is relaxed and dilated,sphincter is relaxed so shunt vessel is relaxed as well
What is the definition of a exocrine gland?
Do not release hormones into blood but instead via ducts