Thermoregulation - C6 Flashcards
Define positive and negative feedback loops
Positive = amplifies stimulus
Negative = reduces stimulus
What is hypothermia?
A temperature too low for metabolic reactions
Death will occur below 32 degrees
What is hyperthermia?
A temperature too high and tissue is damaged
Deadly above 40 degrees
Can be an example of a positive feedback loop
What does the receptor TRPV1 detect?
Can detect both change in temperature and spice within food
Outline an example of a negative feedback loop in relation to temperature?
- Temperature stress or inflammatory response
- An action potential is generated
- Thermoreceptors in brain access the information
- A response in initiated using motor neurons
- Hormone action
What hormone action is created in a negative feedback loop with regard to temperature?
Stimulus - low temperature (detected by nerves in skin)
Control center/effector 1 - hypothalamus creates more Thyroid Stimulating Hormone
Effector 2 - Thyroid gland makes more Thyroxine
Effect - Thyroxine carried through blood and acts on most cells causing them to increase their metabolic rate (cellular respiration) which increases core body temperature through the byproduct of heat produced in these reactions
Define Vasoconstriction
Motor neuron response when cold
Define Vasodilation
Motor neuron response when hot
Name three adaptations to cold
Huddling, a round shape and high metabolic rate
Name three adaptations to heat
Licking fur/skin, long thin shape, low metabolic rate
How is positive feedback dangerous in hyperthermia?
The metabolic rate is raised which further increases core temperature, resulting in a chain reaction of tissue destruction and proteins denature (lose their shape)
