Introduction to Body Temperature Regulation

00:00 Hello, today we are going to talk about the regulation of body temperature.

00:05 So let’s start right in to what is body temperature? Body temperature is really quite simple. It is the heat production minus the heat loss.

00:15 So there are five main ways to have heat production. But the most important, that it comes is the most kilocalories burnt per day is in basal metabolic rate or basal metabolism.

00:27 So this involves to simply not doing anything, just being alive you’re burning kilocalories, and this is an important process of your metabolism. This can a course change with there is a different condition, such as, if you have a high thyroid metabolism or a thyroid hormones, you have an increasing metabolism.

00:46 If you have a low amount of thyroid hormones, you have a decreasing metabolism.

00:51 The Thermic Effect of Food is another way you increase heat production. As you intake food, you need to digest and absorb those food macromolecules. You need to repackage them into different portion, so you can use fats, and carbohydrates, and proteins, and all that takes energy. And that energy part that is heat liberation.

01:16 Finally, anytime you move whether it be you are simple wiggling in your seat, you are walking to and throw with activities of daily living. Or if you are actively exercise it all produce heat.

01:29 So base on the metabolism, thermic effect of food, and exercise are all normal ways you increase heat production.

01:36 The final two ways of increasing heat production are usually associated with a cold stress.

01:42 If you are involved in an area, which is very cold, sometimes you can shiver.

01:47 Shivering is muscle contraction without involving any useful work and that produces heat.

01:54 The final way is through brown adipose tissue. Brown adipose tissue is a very specialize form of adipose tissue. And what happens here is, there is an increase in the heat production because your mitochondria will produce heat. And in this specific adipose tissue is there are high concentration of mitochondria, and have a specific protein in them that uncouples oxidized phosphorylation.

02:20 Therefore, as you increase the amount of energy production more heat is liberated.

02:25 Now, brown adipose tissue is most important in the infant less important in the adult.

02:32 Now, there are four primary wares of heat loss, and it involves radiation, conduction, convection and evaporation.

02:40 Radiation is the first one we talk about, and then involves simply a movement of heat between two bodies or two objects. And this base upon the temperature, which each of those objects are. And there’ll be electromagnetically waves between those two objects, a hot object to a cold object. So usually, your body is warmer, then let’s say, a wall that’s too next to, and so, you are radiate heat out towards that colder object.

03:11 Conduction is less important in terms of heat loss, because they’re need to be direct physical contact between two substances or items that are different temperatures. So you need to be right in close proximity to that object. And so, if you are standing up, you only parts that you have good conduction with is at your feet. Now, if you are sitting down on a chair, that’s a little bit different. Now, you have a little bit of conduction between your back and your upper legs.

03:41 But again, the amount of availability of losing heat via conduction is usually limited.

03:48 Convection is more widely used as heat loss mechanism, but this needs to have some sort of medium.

03:55 And that medium can either be air or water. And why this is important, is that air rushes across the skin, you heat up the air right above the skin layer. But then, the wind or movement blows past it. And therefore, you have to heat up another layer of air. And so, the more that’s wiped across or a more as blown across the skin the more you have to heat up.

04:22 Finally, Evaporation only occurs as a heat loss mechanism. And for this particular one, this is involved the amount of sweating that a person undergoes can then be used as vapotory sweat.