Question

1. Name and describe the body’s three lines of defense for immunity.

2. Name and describe the five major types of white blood cells. What are their lab values?

3. Local inflammation generally produces what classic signs?

4. Describe the multistep process of inflammation.

Answer 1

The immune system can be divided into three basic lines of defense against pathogenic infection:

• The first line of defense against infection are the surface barriers that prevent the entry of pathogens into the body
• The second line of defense are the non-specific phagocytes and other internal mechanisms that comprise innate immunity
• The third line of defense are the specific lymphocytes that produce antibodies as part of the adaptive immune response

Monocytes. They have a longer lifespan than many white blood cells and help to break down bacteria. 100-700 per mm³ (2–8%)

Lymphocytes. They create antibodies to fight against bacteria, viruses, and other potentially harmful invaders.1000-4000 per mm³ (20–40%

Neutrophils. They kill and digest bacteria and fungi. They are the most numerous type of white blood cell and your first line of defense when infection strikes.2500-8000 per mm³ (55-70%)

Basophils. These small cells seem to sound an alarm when infectious agents invade your blood. They secrete chemicals such as histamine, a marker of allergic disease, that help control the body's immune response.50-500 per mm³ (1–4%)

Eosinophils. They attack and kill parasites and cancer cells, and help with allergic responses.25-100 per mm³ (0.5-1%)

Classical signs of inflammation are

• Redness.
• Heat.
• Swelling.
• Pain.
• Loss of function

When inflammation happens, chemicals from your body's white blood cells enter your blood or tissues to protect your body from invaders. This raises the blood flow to the area of injury or infection. It can cause redness and warmth. Some of the chemicals cause fluid to leak into your tissues, resulting in swelling. This protective process may trigger nerves and cause pain.

Higher numbers of white blood cells and the things they make inside your joints cause irritation, swelling of the joint lining, and loss of cartilage (cushions at the end of bones) over time.