Fisiologi Demam, Pathway Demam

Summary

This video explains the pathophysiology of fever, focusing on how infections or injuries trigger immune responses that raise body temperature. The process begins when cells are damaged, leading to the release of toxins that activate immune cells. These cells release histamine and pyrogens that induce inflammation and raise the body’s temperature set point in the hypothalamus. Fever helps fight infection by weakening bacteria, but excessive heat can be dangerous, especially for children. The video emphasizes the immune system's crucial role in defending the body and the mechanisms that contribute to fever.

Takeaways

• 😀 Fever is often caused by infections or tissue injuries, triggering an immune response in the body.
• 😀 White blood cells, like mast cells and basophils, release histamine, which causes blood vessels to expand and attract more white blood cells to the infection site.
• 😀 Histamine plays a key role in inflammation by increasing blood flow and helping immune cells migrate to the affected area.
• 😀 The release of pyrogens (such as interleukins) by white blood cells signals the brain to increase the body's temperature setpoint.
• 😀 The hypothalamus, when triggered by pyrogens, raises the body's temperature to help fight infection.
• 😀 To reach a higher temperature, the body responds with mechanisms like shivering and vasoconstriction to conserve heat.
• 😀 Shivering increases muscle activity, which raises body temperature by boosting metabolism.
• 😀 Vasoconstriction helps retain heat by narrowing blood vessels near the skin, preventing heat loss.
• 😀 Elevated body temperature weakens bacterial cells, making them easier to defeat by the immune system.
• 😀 While fever is helpful in fighting infections, excessively high temperatures, especially in children, can be harmful and may cause seizures.
• 😀 The immune system’s role in fighting infection is supported by raising the body's temperature, but excessive heat must be monitored carefully to avoid complications.

Q & A

What triggers the onset of fever?

Fever is triggered by tissue injury or infection. This could be physical injury to the tissue or infection caused by bacteria, viruses, or other microorganisms.

How do mast cells and basophils contribute to the immune response during an infection?

Mast cells and basophils are immune cells that release histamine in response to infection or injury. Histamine increases blood vessel permeability, attracting white blood cells to the site of infection or injury.

What is the role of histamine in the immune response?

Histamine acts as an inflammatory mediator that causes blood vessels to dilate, allowing white blood cells like monocytes, macrophages, and fibroblasts to accumulate at the site of infection. It also causes swelling and redness in the affected area.

What are pyrogens and how do they affect the body?

Pyrogens are substances that induce fever. Endogenous pyrogens like IL-1 and IL-6 are released by white blood cells during infection, and they travel to the brain, where they stimulate the hypothalamus to raise the body's temperature set point.

How does the body increase its temperature when the set point is raised?

The body increases its temperature through mechanisms like shivering, which generates heat by activating muscles, and vasoconstriction, which reduces heat loss by narrowing blood vessels in the skin.

What is the role of prostaglandin in the fever response?

Prostaglandins are produced in the hypothalamus in response to pyrogens like IL-1 and IL-6. They help to raise the body’s temperature set point, leading to fever as part of the immune response.

Why does the body experience chills during fever?

Chills occur as the body attempts to reach a new, higher temperature set point by generating heat through muscle activity. This is part of the process of increasing body temperature to fight infection.

What is the purpose of vasoconstriction during fever?

Vasoconstriction helps the body retain heat by reducing blood flow to the skin, preventing heat from escaping the body. This assists in raising the body temperature during a fever.

Why does the body need to increase its temperature during an infection?

Raising the body temperature helps to weaken bacterial proteins, making it easier for white blood cells to attack and eliminate the bacteria, thus aiding in the fight against infection.

What are the risks of high fever, particularly in children?

High fever can be dangerous, especially in children, as it can lead to complications like seizures due to the sensitivity of their brain to temperature changes.