Question

Heat and redness, or ____ occur when the small blood vessels in an inflamed area dilate (open up), bringing more blood much closer to the surface of the skin.

Short answer

swelling

Step-by-step solution

Identify the Possible Answers

The passage refers to symptoms of inflammation. Typical symptoms of inflammation include heat, redness, swelling, and pain. The task is to find which one fits in the context where small blood vessels dilate.

Check Context Clues

The passage mentions heat and redness as occurring due to blood vessels dilating. We need a term that fits with heat and redness, which are direct effects of increased blood supply near the skin surface.

Eliminate Incorrect Options

Swelling and pain do not directly relate to the description of blood vessels dilating and bringing more blood to the surface of the skin. Thus, swelling and pain can be ruled out.

Select the Correct Term

Given that heat and redness are mentioned, and blood supply increases near the skin surface, the correct term to complete the sentence is 'swelling'.

Key concepts

Heat

Heat is one of the classic signs of inflammation. When an area of the body becomes inflamed, the small blood vessels in that area dilate—or widen—allowing more blood to flow through. This increase in blood flow raises the temperature of the inflamed area, which is why it feels warm to the touch. Increased blood flow and heat help to speed up the process of healing by bringing more immune cells to the affected area. These cells help to fight off infection and repair damaged tissues. In summary, heat during inflammation acts as a natural defense mechanism.

Redness

Redness is another common symptom of inflammation, often noticed alongside heat. Much like heat, redness occurs because of the dilation of blood vessels. When these blood vessels widen, they bring a larger supply of blood closer to the skin's surface. This increased blood flow can make the skin appear red in the affected area. Redness is a visual indication that the body is actively working to address the inflammation by delivering essential nutrients and immune cells to the site.
Redness and heat usually go hand-in-hand due to the same underlying mechanism of increased blood flow in response to inflammation.

Dilation of Blood Vessels

Dilation of blood vessels is a crucial process during inflammation. The term 'dilation' means that the blood vessels open up or widen. This allows a greater volume of blood to flow into the affected area. When inflammation occurs, the body releases chemical signals that prompt the blood vessels to dilate.
Essentially, dilation helps in several ways:

• It increases the supply of oxygen and nutrients to the injured tissue.
• It helps transport immune cells to the site to fight off any potential infections.
• It aids in the removal of waste products from the inflamed area.

Dilation is fundamental to the body's inflammation response and helps accelerate the healing process.

Surface Blood Supply

Inflammation leads to a notable increase in surface blood supply. When the blood vessels dilate, they bring a higher amount of blood to the surface of the skin. This is why inflamed areas often appear red and feel warm. The increased surface blood supply serves multiple purposes:

• Delivering essential nutrients and oxygen to the damaged tissue.
• Providing a pathway for immune cells to reach the site of inflammation quickly.
• Helping to remove toxins and waste products from the affected area.

Thus, the increase in surface blood supply is not just a symptom but a vital part of the healing process, ensuring that all necessary elements reach the inflamed tissue efficiently.