Integumentary System: Thermoregulation - Online Tutor, Practice Problems & Exam Prep

The integumentary system regulates body temperature through two primary methods: vasoconstriction and vasodilation, and sweating. Vasoconstriction narrows blood vessels to retain heat in cold conditions, while vasodilation widens them to release heat when the body is hot. Additionally, sweating cools the body as sweat evaporates from the skin's surface. These processes are essential for maintaining homeostasis, ensuring the body can adapt to varying external temperatures effectively.

Introduction to Thermoregulation

This video, we're going to continue to talk about the integumentary system as we talk about one of its main functions of thermoregulation. Recall that the integumentary system has many 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. Thermoregulation is the process of maintaining a stable internal body temperature. The integumentary system actually has two main methods of thermoregulation that we have numbered down below: Number 1 and Number 2.

The first main method is altering the diameter of blood vessels near the skin via vasoconstriction and vasodilation. The second main method is sweating. 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.

Vasoconstriction & Vasodilation

In this video, we're going to talk about the integumentary system's first method of thermoregulation, which is vasoconstriction and vasodilation. Altering the diameter of blood vessels in the dermis of our skin, which is near the surface, actually thermoregulates the body, allowing our body to maintain internal body temperature despite the fact that the temperature on the outside of our bodies can change. Vasoconstriction refers to blood vessels constricting, which means that those blood vessels decrease in their diameter. Vasoconstriction of blood vessels occurs when the body is cold.

What helps me remember that vasoconstriction occurs when the body is cold is that the 'CO' in constriction reminds me of the 'CO' in cold. When blood vessels in the dermis near the surface of the skin undergo vasoconstriction, this decreases blood flow to the skin. Ultimately, this allows the body to retain heat under cold conditions. The body is able to retain heat through vasoconstriction because a decrease in blood flow to the skin results in less blood near the surface of the skin and less blood radiating heat to the external environment. We are able to retain heat by preventing heat loss to the environment through vasoconstriction.

On the other hand, vasodilation is a term that refers to blood vessels dilating or increasing in their diameter. This occurs when the body is hot or when the temperatures are high. Hopefully, the rhyming of vasodilation with high temperatures can remind you that vasodilation occurs when the body is hot. When blood vessels in the dermis near the surface of the skin undergo vasodilation, this increases blood flow to the skin.

With increased blood flow to the skin, blood will rush toward the surface of the skin, meaning more heat can radiate from the blood to the external environment, thereby allowing our body to cool off by facilitating heat loss to the environment. Let's take a look at this image below, where we start to piece things together, focusing on vasoconstriction on the left hand side and on vasodilation on the right hand side.

Recall that vasoconstriction occurs when it's cold outside, and the blood vessels constrict. Notice the little snowflakes to indicate that it is cold, and that the person is shivering, showing it's really cold. The diameter of the inside of the blood vessels is very small, which means less blood rushes toward the surface of the skin, leading to less heat radiating from the blood to the external environment. The yellow arrows represent the body's heat loss, showing there's a lot less heat loss during vasoconstriction of the blood vessels in the dermis, allowing the body to retain heat and ultimately helping to warm the body. On the right hand side, we are showing vasodilation, which occurs when it's hot outside and the temperatures are high, allowing the blood vessels to widen or dilate.

The diameter of the blood vessel here is much larger in comparison to that with vasoconstriction. When the blood vessels dilate, more blood rushes toward the surface of the skin and allows heat to radiate from the blood to the external environment. There's a lot more heat loss with the vasodilation of the blood vessels near the surface of the skin, and this will facilitate heat loss to help cool off the body under these hot conditions. When there's more blood rushing to the surface of your skin, that can actually cause your skin to turn a reddish color, responsible for the red flushing face that you get when your body is really overheated. This concludes our brief lesson on the vasoconstriction and vasodilation of blood vessels in the dermis of the skin to allow for thermoregulation. We'll be able to get some practice learning this and talk more about thermoregulation via sweating as we move forward. I'll see you all in our next video.

Integumentary System: Thermoregulation Example 1

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 4 potential answer options down below. Now, option A says the heat released from sweat evaporating. 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.

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. So, again, it's not going to create a red flushed appearance on her 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.

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 are not going to be enough to create the red flushed appearance on her face. And so, 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 dilate. This tells us that vasodilation of blood vessels is going to be the correct answer.

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.

Sweating

This video we're going to talk about the integumentary system's second method of thermoregulation, which is sweating. Sweat or perspiration is a water-based solution secreted onto the surface of the skin by sweat glands when the body gets too hot. The body is actually cooled down when the sweat evaporates off the surface of the skin. Notice in the diagram of the integumentary system below, you can see these sweat glands throughout the dermis. These sweat glands are exocrine glands because they secrete the sweat onto the surface of the skin.

Notice here that these little bubbles that you see are the sweat puddles themselves. The red lines coming off of the sweat puddles represent the evaporation of the sweat. It's when the sweat evaporates off the surface of the skin that the body is actually cooled down. Later in our course, we're going to talk more about sweat and sweat glands. But for now, this 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.

Here’s what students ask on this topic:

What is the role of the integumentary system in thermoregulation?

The integumentary system plays a crucial role in thermoregulation by maintaining a stable internal body temperature. It achieves this through two primary methods: vasoconstriction and vasodilation, and sweating. Vasoconstriction narrows blood vessels near the skin's surface to retain heat in cold conditions, while vasodilation widens them to release heat when the body is hot. Additionally, sweating cools the body as sweat evaporates from the skin's surface. These processes are essential for maintaining homeostasis, ensuring the body can adapt to varying external temperatures effectively.

How does vasoconstriction help in thermoregulation?

Vasoconstriction helps in thermoregulation by narrowing the blood vessels near the skin's surface when the body is cold. This reduces blood flow to the skin, minimizing heat loss to the external environment. By retaining more heat within the body, vasoconstriction helps maintain a stable internal temperature under cold conditions. The reduced diameter of the blood vessels means less blood is exposed to the cooler external temperatures, thereby conserving body heat.

What is the difference between vasoconstriction and vasodilation in thermoregulation?

Vasoconstriction and vasodilation are two opposing mechanisms in thermoregulation. Vasoconstriction occurs when blood vessels near the skin's surface narrow, reducing blood flow and heat loss, which helps retain heat in cold conditions. In contrast, vasodilation involves the widening of these blood vessels, increasing blood flow to the skin and facilitating heat loss to cool the body in hot conditions. Both processes are essential for maintaining a stable internal body temperature and ensuring homeostasis.

How does sweating contribute to thermoregulation?

Sweating contributes to thermoregulation by cooling the body when it gets too hot. Sweat, a water-based solution, is secreted onto the skin's surface by sweat glands. As the sweat evaporates, it absorbs heat from the skin, thereby cooling the body. This process is particularly effective in hot conditions, helping to lower the internal body temperature and maintain homeostasis. The evaporation of sweat is a key mechanism for dissipating excess heat and preventing overheating.

What are the primary methods of thermoregulation in the integumentary system?

The primary methods of thermoregulation in the integumentary system are vasoconstriction and vasodilation, and sweating. Vasoconstriction narrows blood vessels to retain heat in cold conditions, while vasodilation widens them to release heat when the body is hot. Sweating cools the body as sweat evaporates from the skin's surface. These mechanisms work together to maintain a stable internal body temperature, ensuring the body can adapt to varying external temperatures effectively.