Physiology of fever

Question 1

What is a fever?

Answer 1

Fever is a physiological response normally to an infection.
It is initiated as part of an immune response.
High temperature of greater than 37.8 degrees Celsius.

Question 2

What cells does the immune system send in response to infections?

Answer 2

• White blood cells
• Cytokines

Question 3

What are macrophages?

Answer 3

A type of white blood cell that ‘eat’ and destroy bacteria and other antigens.

Question 4

What are cytokines?

Answer 4

Chemical messengers that are released by white blood cells to assist with fighting infections.
One type is pyrogen that is responsible for generating a fever.

Question 5

What is the hypothalamus’ role in fever?

Answer 5

The Pyrogenic Cytokines target the hypothalamus region in the brain.
They stimulate the hypothalamus to release a chemical called prostaglandin.

Question 6

What affects does prostaglandin have on the body?

Answer 6

• Vaso-constriction (narrowing) of blood vessels
• Shivering response via muscles

Question 7

What are the benefits of fever?

Answer 7

• Raised temperature stimulates immune system function and white blood cell production
• Higher temperatures directly inhibit growth of bacteria or harms them
• Most infectious antigens can’t survive long a few degrees hotter than body temperature

Question 8

What are the negatives of fever?

Answer 8

• A 2 degree rise in temperature equals 20% extra energy requirement
• Causes discomfort and pain
• Can lead to serious levels of dehydration
• Affects and damages normal processes of the body including all enzyme reactions
• Rarely can lead to organ damage if very high for a longer period of time

Question 9

What is the medical term for fever?

Answer 9

Pyrexia