Feedback Mechanisms Flashcards
Define negative feedback
Reverse the direction of change back towards the optimum
Define positive feedback
Causes more and more change away From the optimum
Why have separate mechanisms That control departures in different directions from of state
Allows for greater control
Importantance of negative feedback
Without feedback the receptors continue to stimulate the effector and over correct leading to deviation away from the original
What does positive feedback lead to
Usually occurs when control systems breaks down and leads to death
What part of the brain monitors blood temp
The hypothalamus
Receptor that detects temp change
Thermoreceptors
Physiological mechanisms to cold down the body
Vasodilation, sweating, lowering body hair
Physiology mechanisms to raise body temp
Vasoconstriction, shivering , raising body hair
Vasodilation
- diameter of kin arteries near the surface of the is made larger
- warm blood passes close to the skin surface via capillaries
- heat from blood is radiated way from the body
Vasoconstriction
- diameter of arteries near the surface of the skin is made smaller
- reduces volume of blood reaching skin surface through capillaries
- most blood passes under insulating fat
