Integumentary System: Thermoregulation

In this video, we're going to continue to talk about the integumentary system as we talk about one of its main functions of thermoregulation. And so recall that the integumentary system has a lot of different functions. And one of those functions is that it plays an important role in maintaining homeostasis or maintaining internal conditions. Despite the fact that outside conditions change. Now thermoregulation is the process of maintaining a stable internal body temperature. Now, the the integumentary system actually has two main methods of thermoregulation that we have numbered down below. Number one and number two, the first main method is altering the diameter of blood vessels near the skin via vasoconstriction and vasodilation. And the second main method is sweating. And so moving forward in our course, we're going to talk about each of these two methods of thermoregulation in their own separate videos starting with vasoconstriction and vasodilation. So I'll see you all in our next video.

In this video, we're going to talk about the integumentary system's first method of thermoregulation, which is vasoconstriction and vasodilation and so altering the diameter of blood vessels in the dermis of our skin, which we know is near the surface of the skin. Actually thermo regulates the body allowing our body to maintain internal body temperature despite the fact that the temperature on the outside of our bodies can change. And so the term vasoconstriction refers to blood vessels constricting, which means that those blood vessels decrease in their diameter. Now, the vasoconstriction of blood vessels occurs when the body is cold. And what helps me remember that vasoconstriction occurs when the body is cold. Is the co in constriction reminds me of the co in cold. And so when blood vessels and the dermis near the surface of the skin undergo vasoconstriction, this actually decreases blood flow to the skin. And ultimately, this allows the body to retain heat under cold conditions. Now, the reason that the body is able to retain heat through vasoconstriction is because with a decrease in blood flow to the skin, there is less blood near the surface of the skin and less blood radiating heat to the external environment. And so ultimately, we are able to retain heat by preventing heat loss to the environment through vasoconstriction. Now, on the other hand, vasodilation is a term that refers to blood vessels dilating or increasing in their diameter. And this occurs when the body is hot or when the temperatures are high. And so, notice that vaso dilation rhymes with high temperatures. And so hopefully, that can remind you that vasodilation occurs when the body is hot. Now, when blood vessels in the dermis near the surface of the skin undergo vasodilation, this actually increases blood flow to the skin. And with increased blood flow to the skin, blood will be rushing toward the surface of the skin. And that means that more heat can radiate from the blood to the external environment, allowing our body to cool off again by facilitating heat loss to the environment. And so let's take a look at this image down below where we can start to piece things together. And notice that on the left hand side, we're focusing on vasoconstriction. Whereas on the right hand side, we're focusing in on vasodilation. Now recall that vasoconstriction uh occurs when it's cold outside and when it's cold, the blood vessels are going to constrict. And so notice that here we have these little snowflakes to show you that uh it is cold and notice that this person is shivering. So we know it's really, really cold and notice that their blood vessels are actually constricting, their diameter is smaller. And so here, the diameter of the inside of the blood vessel is very, very small. And so ultimately, what this means is less blood rushing toward the surface of the skin. And that means that there will be less heat radiating from the blood to the external environment. And so notice that these little yellow arrows that you see throughout represent heat, the body's heat loss. And so there's a lot less heat loss when uh vasoconstriction of the blood vessels in the dermis occurs, allowing the body to retain heat and ultimately helping to warm the body. Now, on the right hand side, we're showing you vasodilation and again, vasodilation occurs when it's hot outside and the temperatures are high. And that allows the blood vessels to widen or to dilate if you will. And so notice that the diameter of the blood vessel here is much, much larger in comparison to the diameter of the blood vessel uh with vasoconstriction on the left hand side. And so when the blood vessels dilate like this, more blood rushes toward the surface of the skin, and that allows heat to radiate from the blood to the external environment. And so notice that there's a lot more heat loss with the vasodilation of the blood vessels near the surface of the skin. And so that will facilitate heat loss to help cool off the body under these hot conditions. And so when there's more blood rushing to the surface of your skin, that can actually allow for your skin to turn a reddish color. And so that's responsible for the red flushing face that you get when your body is really, really overheated. And so this year concludes our brief lesson on the vasoconstriction and vasodilation of blood vessels in the dermis of the skin to allow for thermoregulation. And we'll be able to get some practice learning this and talk more about thermoregulation via sweating as we move forward. So I'll see you all in our next video.

So here we have an example problem that says after exercising on a hot day, Paula has a red flushed appearance on her face, what caused this and we've got these four potential answer options down below. Now, option A says the heat release from sweat evaporating. Now, although it's true that Paula is probably sweating a lot after exercising on a hot day, that sweat is not going to create a red flushed appearance on her face. And so for that reason, we can eliminate answer option A as we'll learn, moving forward, sweat is a water based solution. And so it is going to be clear and colorless. And so again, it's not going to create a red flushed appearance on our face. Now, moving on, option B says increased oxygen levels in the blood, but when we're exercising, our muscles are actually consuming more oxygen in the blood. And so it's very possible that the blood oxygen levels are actually decreased instead of increased as option B suggests. And oxygen itself is a colorless gas and the oxygen levels in the blood is not going to be enough to create the red flushed appearance on her face And so uh for that reason, we can eliminate answer. Option B. So now we're between either option C or option D. And what you'll notice is option C says vasoconstriction of blood vessels. Whereas option D says vasodilation of blood vessels. And so recall that on a hot day when the temperatures are high, our blood vessels are going to die late. And so this tells us that vasodilation of blood vessels is going to be the correct answer and recall that with vasoconstriction, the co here can remind you that this occurs when it is cold outside. But again, this is a hot day. So we know that it's not going to be vasoconstriction. That's why we can eliminate answer option C and indicate that option D is the correct answer to this example. And that concludes this example. So I'll see you all in our next video.

Given what you know about homeostasis, which type of feedback loop do you think vasoconstriction and vasodilation are classified as?

• A. Negative feedback loop.
• B. Positive feedback loop.

In this video, we're going to talk about the integumentary system's second method of thermoregulation, which is sweating. And so sweat or perspiration is a water based solution secreted onto the surface of the skin by sweat glands when the body gets too hot. Now, the body is actually cool down when the sweat evaporates off of the surface of the skin. And so notice down below, we have a diagram of the integumentary system and notice you can see these sweat glands throughout the Dermus here and notice that these sweat glands are exocrine glands because they secrete the sweat onto the surface of the skin. And so notice here that these little bubbles that you see are the sweat puddles themselves. Now notice that these red lines coming off of the sweat puddles are lines that represent the evaporation of the sweat. And again, it's when the sweat evaporates off the surface of the skin when the body is actually cooled down. Now, later in our course, we're going to talk more details about sweat and sweat glands. But for now, this year concludes our video on sweating and we'll be able to get some practice applying these concepts moving forward. So I'll see you all in our next video.

What happens in the integumentary system of a person who is overheating?

• A. Blood vessels dilate and sweat glands are inactive.
• B. Blood vessels dilate and sweat glands are active.
• C. Blood vessels constrict and sweat glands are inactive.
• D. Blood vessels constrict and sweat glands are active.