Temperature Regulation By the end of the lesson you will know How the body corrects overheating How the body corrects overcooling What thermo receptors do? What voluntary responses are carried out to control temperature

Why do we need to regulate: Internal body temperature To provide the optimum conditions for enzymes and chemical reactions

Body Temperature Normal body temperature is 370C. Temperatures above this: denature enzymes and block metabolic pathways Temperatures below this: slow down metabolism and affect the brain.

Thermostats Temperature is set on a thermostat Too cool? Heater kicks on and temperature goes up Too warm? Heater stays off until room cools down Constant checking : turning on and off

Homeostasis: feedback control of temperature Feedback loop- A cycle Conditions continually monitored, brought into balance, re-monitored etc. ( many homeostatic loops regulate our bodies) Examples? Examples Blood sugar, heart rate, breathing rate, etc

3 basic components of a feedback system 1) receptor(s) Sensor(s) that reports a change (stimuli) 2) control center evaluates input and sends output 3) effector receives output to produce a response

Body Temperature Control The Hypothalamus acts as a thermostat Receives info from thermo receptors in the skin. Receptors in the hypothalamus monitor blood temperature.

Primary skin response Vasoconstriction & Vasodilation

It’s too hot…. Vasodilation Sweating

Cooling down When it's hot and you need to cool down, muscles relax. Hairs lie close to the skin. Air does not act as an insulating layer.

Cooling Down Sweating How does it work? Heat energy in the body is absorbed by H20 converting liquid to gas. Leaves the body cooler

It’s too cold…. Causes vasoconstriction. Shivering- burning fuel To make heat

Keeping warm When it's cold, the muscle pulls the hair up. A layer of warm air accumulates around the hair to insulate Holds Heat

Voluntary responses In humans our cerebrum “Knows” that we feel cold or hot We then put on more clothes, eat a hot meal, exercise etc.

This powerpoint was kindly donated to www.worldofteaching.com http://www.worldofteaching.com is home to over a thousand powerpoints submitted by teachers. This is a completely free site and requires no registration. Please visit and I hope it will help in your teaching.