inflammation

Question 1

What is inflammation?

Answer 1

• Inflammation is a non-specific immune response
• Body’s response to tissue injury, creating an environment for restoration and repair. Inflammation of tissue arises in the connective tissue.

Question 2

What are the functions of inflammation?

Answer 2

• Limits spread of pathogens
• Removes any cell bodies & pathogens from damaged tissue
• Sets the stage for tissue repair
• Alerts the adaptive immune system to threat of infection.

Question 3

What are the 5 cardinal signs of inflammation?

Answer 3

• Pain
• Heat
• Redness
• Swelling
• Loss of function (but mostly only four, loss of function doesn’t usually count)

Question 4

Explain heat as an inflammation sign

Answer 4

• Hypermia (increased blood flow) results in more heat being transported by blood to affected areas.
• This leads to a faster repair process because heat increases metabolic rate of cells.
• The heat can also get rid of bacteria, reducing signs of infection

Question 5

Explain swelling as an inflammation sign

Answer 5

• Increased permeability (leakiness) of blood vessels results in more fluid leaking from the capillaries into interstitial space.
• This limits movement of injury site, enhancing speed of repair.

Question 6

Explain pain as an inflammation sign

Answer 6

• Chemicals released from cells stimulate local nerve endings, causing localised pain.
• This is important because it limits the site of injury, leading to faster repair.

Question 7

Explain redness as an inflammation sign

Answer 7

• Vasodilation of nearby blood vessels and hypermia (increased blood flow) to area.
• This means more white blood cells and chemicals to the area, leading to a faster repair.

Question 8

Explain the process of inflammation: inflammatory chemicals.

Answer 8

1. Inflammation begins with a chemical alarm, which is a large number of inflammatory chemicals being released from damaged cells. Mast cells are key to generating the alarm, they include: histamine, complement, kinins, prostaglandins.
2. Phagocytes which are white blood cells, eat the invading pathogens. This starts the process of phagocytosis which is gobbling up unwanted pathogens and bacteria.

Question 9

How are phagocytes mobilised?

Answer 9

1. Leukocytosis= increase in WBC which stimulates release of neutrophils
2. Margination= Inflamed endothelial cells tell phagocytes to cling to the inner wall of blood capillaries.
   Inflamed endothelial cells send out chemicals called ‘cell-adhesion molecules’ or
   CAMs.
   CAMs signal to phagocytes that this is the area that they should adhere to.
3. Diapedis= continued chemical signalling encourages neutrophils to flatten and squeeze through endothelial cells of the capillary wall.
4. Chemotaxis= inflammatory chemicals signal to neutrophils and WBC, to move towards them and the site of injury. They are known as chemotactic agents in this role.

Question 10

What are monocytes?

Answer 10

• Produce lysomes which turn into macrophages, and these are effective phagocytes. Monocytes follow neutrophils to site of injury. This happens after the process of mobilising the phagocytes.

Question 11

What are macrophages?

Answer 11

• Key in disposing remaining pathogens, dead tissue cells and other debris, ready for tissue repair and wound healing

Question 12

Pus=

Answer 12

Mix of dead/ dying neutrophils, tissue and living and dead pathogens.
This also happened after the process of mobilising the phagocytes.

Question 13

Explain a bit about the chemicals being released by damaged cells

Answer 13

• Histamine= vasodilation, increased permeability of blood vessels
• Kinins= vasodilation, increased permeability of blood vessels
• Prostaglandins= intensify histamine and kinin effects
• Leukotrienes= increased permeability of blood vessels, phagocytic attachment