15.3 Thermoregulation In Endotherms

Question 1

How do endotherms detect temperature changes

Answer 1

Use peripheral temperature receptors that are located in the skin and detect changes in surface temp

Question 2

What do the temperature receptors in the hypothalamus detect and what do they act as

Answer 2

Temperature changes deep within the blood

They act as the thermostat of the body controlling the responses that maintain the core temp

Question 3

What ways do endotherms cool down

Answer 3

Vasodilation by forcing blood to skin surface
Increased sweating - lose heat and cools blood
Reduce insulating effect of hair/feathers

Question 4

How does the reduced insulation effect of hair and feathers work

Answer 4

Hair elector muscles in skin relax and this avoids trapping an insulating layer of hair

Question 5

How do endotherms warm up

Answer 5

Vasoconstriction- little blood flows through the capillary network close to skin surface
Decreased sweating
Raising body hair and feathers
Shivering

Question 6

How can raising body hairs and feathers warm up endotherms

Answer 6

Erector pili muscles in skin contract and hairs go erect this traps an insulating layer of air and reducing cooling

Question 7

How does shivering warm up endotherms

Answer 7

Rapid involuntary contracting abs relaxing of large voluntary muscles
The metabolic heat warms up the body

Question 8

What physiological adaptations have endotherms got to help them keep warm

Answer 8

Thick layers of insulting fat underneath skin

Hibernation - lowers metabolic rate and build up fat stores

Question 9

What centres are used in endotherms to control thermoregulation

Answer 9

Heat loss centre - when temp of blood flowing through hypothalamus increases this centre is activated

Heat gain centre