Chapter 22

Question 1

What are pathogens?

Answer 1

Microscopic organism that causes diseases:
- viruses
- bacteria
- fungi
- parasites

Question 2

What does the lymphatic system do?

Answer 2

protects us against disease
Lymphatic system cells respond to:
- Environmental pathogens
- toxins
- Abnormal body cells, such as cancers

Question 3

What does Immune system do?

Answer 3

Immunity
- The ability to resist infection and disease
All body cells and tissues involved in production of immunity

Question 4

What are the types of Lymphocytes

Answer 4

1. T cells - Thymus-dependent
2. B cells - bone-marrow - derived
3. NK cells - Natural killer cells

Question 5

Organization of the Lymphatic System

Answer 5

1. Lymph - a fluid similar to plasma but does not have plasma proteins (most water)
2. Lymphatic vessels (lymphatics)- Carry lymph from peripheral tissues to the venous system
3. Lymphoid tissues and lymphoid organs
4. Lymphocytes, phagocytes, and other immune system cells