Homeostasis Flashcards
What is homeostasis?
Any self-regulating process by which biological systems maintain stability whilst adjusting to variable environmental conditions
What are the control mechanism of homeostasis?
Receptor detects internal environment change
Control centre processes this information and determines if change is outside the equilibrium
If it is, sends a signal to the effector
Effector directs an appropriate response
Are most homeostatic feedbacks positive or negative?
Negative
Do naked mole rats maintain body temperature?
No
Air in burrows remains constant temperature so no need
Homeostatic mechanisms are costly so better to loss them if not needed
What did the experiment with Eastern Pygmy Possums show?
Enters torpor when temperatures drop
Go into a deeper hibernation if temperatures continue to stay low
Experiment measured body temperature, heart rate and oxygen consumption
Found body temperature matches external environment temperature
Oxygen and heart rate drop when temperature drop and stay low even if temperature increases
Can adapt to change in external environmental by switching off systems e.g. temperature regulation
What happens when black bears hibernate?
Can hibernate 5-7 months
Decreased metabolic rate when hibernating
Herat beats in small bursts to match breathing to conserve energy
So heart only beats to transport gases
What is erythropoietin?
Naturally produced as a response to decreased oxygen levels
Causes acclimatisation to higher altitudes
What are the problems with erythropoietin doping?
Thicker blood so heart has to work harder
Increases risk of heart attacks and strokes
What does doping do?
Manipulates homeostatic physiology
What can doping do?
Build muscle mass and strength
Increases oxygen delivery to exercising tissue
Masks pain/injury
Hide use of other drugs
