Thermoregulation

Rise in temperature

• receptors in skin + hypothalamus detect change.

• Thermoregulatory centre detects and sends signals to effectors.

• effectors in skin lay hairs flat, vasodilation, sweat.

• Fall in temp.

Fall in temperature

• receptors in skin + hypothalamus detect change.

• Thermoregulatory centre detects change + sends signals to effectors.

• effectors make hairs stand, vasoconstriction, shivering.

• rise in temp.

Skin as an organ of thermoregulation

• large surface area.

• large capillary network.

• sweat glands.

• Fat cells for insulation

Vasoconstriction

TOO COLD.

• wants to keep blood away from skin.

• arterioles constrict to prevent blood going to capillaries. keeps blood closer to arteries/veins.

Vasodilation

TOO HOT

• wants to keep blood closer to skin.

• arterioles dilate to allow blood to flow close to skin. heat is lost.

Hairs standing

• hairs stand and trap a layer of air. Air acts as insulation.

Endotherms

• maintain a constant body temperature through metabolic processes

Ectotherms

• regulate body temp by external sources.

• unable to increase respiration rate so expose body to sun