Temperature Regulation Flashcards
What is homeostasis?
Maintaining the bodies internal environment to be constant whilst external environmental conditions change. Constant refers to small fluctuations/ stable.
What is negative feedback?
When conditions change away from the ideal, to cause a response to reverse the change back to the normal.
What is the difference between homeostasis and negative feedback?
Homeostasis is the outcome. Negative feedback is the mechanism that allows homeostasis to be achieved.
Describe the basic mechanism of negative feedback?
Change 》Detection by receptors》 Response by effectors 》 Conditions back to norm.
What is the average body temp in humans?
37 °C
Methods for heat generation?
Muscle contraction Release of chemicals- thyroxin Respiration Metabolism Piloerection Vasoconstriction
Methods for heat loss?
Sweating
Vasodilation
Behavioural
What is an endotherm?
An organism that can use internal sources of heat, such as heat generation from metabolism in the liver, to maintain its body temperature.
What is a Ectotherm?
An organism that relies on external sources of heat, e.g.the sun; to regulate its body temperature.
How active are Endotherms?
Endotherms can maintain high activity levels during day and night.
How active are Ectotherms?
Activity levels severly reduced when it’s cold. May be completely inactive in winter.
Energy requirements of Endotherms?
More enegy needed for metabolism
Energy requirements of Ectotherms?
Less energy needed for metabolism
Food requirments of Endotherms?
High food requirements to meet energy demands. Eat regularly.
More food is used for maintaining temperature, less is available for growth.
Food requirments of Ectotherms?
Less food needed in total so can survive long periods without eating.
More food used for growth.
Habitat of Endotherms?
Wide range of habitats including places that are very cold.
Habitat of Ectotherm?
Restricted to tropical or temperate regions a on land but can be found throughout all oceans.
What are the receptors found in the skin that detect temperature changes in skin surface temperature?
Peripheral temperature receptors
What muscles cause you to shiver?
Skeletal Muscles
What is piloerection?
Hairs stand up on skin surface. Create insulating layer to retain body heat.
What receptors detects change in blood temperature?
Receptors in Hypothalamus
What is vasoconstriction?
Where blood vessels near the surface of the skin constrict , moving away from the skin surface. Causing lower amounts of heat to be radiated.
What makes vasoconstriction happen?
- Smooth muscle consricts the arteriole to the capillaries.
- Shunt vessel dilated due to arteriole relaxing.
What is vasodilation?
Where blood vessels near the surface of the skin dilate causing more blood to flow near the skin surface. More heat is radiated/lost.
What causes vasoldilation?
- Arteriole to capillaries dilated.
2. Arteriole to shunt vessel constricted forcing blood into capillaries near skin surface.
How does sweating reduce body temperature?
Sweating results in water on the skin’s surface to evapourate. Evaporation uses lots of heat energy so heat is lost.
How does burrowing help regulate temperature?
- Deserts are cold at night. Ground retains heat from day.
- During hot day send is cooler from night.
- Less air convection in tunnel can increase heat.
How do locusts regulate body temperature?
While body facing Sun to increase surface area. Gain of heat. If too hot, only head faces Sun.
Spiracles increase air flow and evaporation.
How do bees regulate heat?
- Flapping wings creates increased convection. Hear loss.
2. Heat gain by muscle contraction of wings.
How do lizards basking in the sun help with temperature regulation?
- Conduction of heat from ground/rock to lizard. Raising body off ground lowers conduction.
- Frills increase surface area. More hest absorbed from Sun.
