Homeostasis Flashcards
What are constants within the body?
Core body temperature, blood glucose concentration, water potential of blood, concentration of ions in blood, blood pressure and blood pH
Why is core body temprature kept constant?
For enzymes
Why is blood glucose concentration kept constant?
For ATP
Why is water potential of blood kept constant?
So cells do not burst or dehydrate
Why is blood pressure kept constant?
To prevent damage to capillaries
Why is blood pH kept constant?
For enzymes
How are conditions kept stable?
Dynamic equilibrium - they fluctuate around a set point
How are conditions kept constant around a certain point?
Positive and negative feedback
What is positive feedback?
Increasing a change
What are examples of positive feedback?
Lactation, oxytocin and childbirth
What is negative feedback?
Opposing a change and stabilising
What are examples of negative feedback?
Metabolic reaction pathways, insulin production, ADH and body temperature
How are metabolic pathways an example of negative feedback?
The final product inhibits rate of reaction
What are the 2 different types or organisms when it comes to temperature control?
Ectotherms and endotherms
What are ectotherms?
body heat is derived from environment
What are endotherms?
body heat is derived from metabolism
What are characteristics of ectotherms?
Often large diurnal variation, try to control by behavioural methods and behaviour depends on body temperature
What are characteristics of endotherms?
Internal heat from respiration and maintain a constant internal core temperature by controlling amount of heat produced and lost
How do endotherms get heat from respiration?
Enzyme reactions are not 100% efficient
How do endotherms control amount of heat produced and lost?
Physiological and behavioural traits
What are advantages of endotherms?
Able to maintain body temperature independant and markedly different from environment, allowed to be active at al times in all seasons and can exploit areas of the earth that ectotherms cannot survive in
What are disadvantages of endotherms?
body heat is derived from respiration so have high metabolic rate compared to ectotherms, most food intake used for respiration so spend much more time searching for food and eating, usually live in areas lower than body temperature so constantly loosing heat to environment and producing enough heat takes up *0% of food intake
What are ways ectotherms manage body temperature?
Hiding in burrows, body orientation, basking in sun, opening mouth and restricting body contact with hot ground
