Warming up in endotherms

How does vasoconstriction help?

Arterioles near skin’s surface constrict. The arteriovenous shunt vessels dilate so little blood flows through capillary networks close to the skin surface. Skin looks pale and warm blood is kept well below surface

How does decrease sweating help?

As core temp falls, rate of sweating decreases and sweat production stops entirely. This reduces cooling by evaporation of water from the surface to the skin,but some evaporation from the lungs continues

How does raising body hair or feathers help?

As body temp falls, erector pili muscles in the skin contract, pulling the animal’s hair or feathers erect. Traps insulating layer of air and reduces cooling through the skin

How does shivering help?

Rapid involuntary contracting and relaxing of large muscles in the body, the metabolic heat from the exothermic reactions warm up the body

What happens in cold climates?

SA:V is minimised to reduce cooling

What else helps with insulating?

Thick layer of insulating fat under the skin

What do some animals do?

Hibernate and build up fat stores, build a well insulated shelter and lower metabolic rate