Table of contents

1. Introduction to Anatomy & Physiology5h 43m
2. Cell Chemistry & Cell Components12h 36m
3. Energy & Cell Processes10h 6m
4. Tissues & Histology10h 3m
5. Integumentary System2h 20m
6. Bones & Skeletal Tissue2h 16m
7. The Skeletal System2h 35m
8. Joints2h 17m
9. Muscle Tissue2h 33m
10. Muscles1h 11m
11. Nervous Tissue and Nervous System1h 35m
12. The Central Nervous System1h 6m
- Introduction to the Central Nervous System
  18m
- The Cerebrum
  48m
13. The Peripheral Nervous System1h 26m
14. The Autonomic Nervous System1h 38m
15. The Special Senses2h 41m
16. The Endocrine System2h 48m
17. The Blood3h 22m
18. The Heart3h 42m
19. The Blood Vessels3h 35m
20. The Lymphatic System3h 16m
21. The Immune System14h 37m
22. The Respiratory System3h 20m
23. The Digestive System2h 5m
24. Metabolism and Nutrition4h 0m
25. The Urinary System2h 39m
26. Fluid and Electrolyte Balance, Acid Base Balance37m
27. The Reproductive System2h 5m
28. Human Development1h 21m
29. Heredity3h 32m

21. The Immune System

Antigens

Anatomy & Physiology

21. The Immune System

Antigens

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Multiple Choice

Which of the following correctly describes the relationship between a pathogen and an antigen?

Pathogens are molecules that bind to antigens to neutralize them.

Antigens are the cells that pathogens use to replicate within the host.

A pathogen is a type of antigen that directly attacks immune cells.

An antigen is a substance that can trigger an immune response, often found on the surface of a pathogen.

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Verified step by step guidance

Begin by understanding the definitions of 'pathogen' and 'antigen'. A pathogen is an organism, such as a virus, bacteria, or fungus, that can cause disease. An antigen is a molecule or molecular structure, often found on the surface of pathogens, that is recognized by the immune system.

Recognize that antigens are not cells, but rather substances that can trigger an immune response. They are typically proteins or polysaccharides on the surface of pathogens.

Understand that pathogens do not bind to antigens to neutralize them. Instead, the immune system produces antibodies that bind to antigens to neutralize or mark them for destruction.

Clarify that pathogens do not use antigens to replicate within the host. Pathogens may use host cells to replicate, but antigens are simply markers that the immune system recognizes.

Conclude that the correct relationship is that an antigen is a substance that can trigger an immune response, often found on the surface of a pathogen, helping the immune system identify and respond to the pathogen.