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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

Major Histocompatibility Complex Molecules

Anatomy & Physiology

21. The Immune System

Major Histocompatibility Complex Molecules

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Multiple Choice

Once an MHC II molecule on an APC presents an antigen:

Effector cells with CD8 markers activate the APC.

Effector cells with CD4 kill the APC.

Effector cells with CD8 kill the APC.

Effector cells with CD4 activate the APC.

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Verified step by step guidance

Understand the role of MHC II molecules: MHC II molecules are found on antigen-presenting cells (APCs) and are responsible for presenting processed antigens to helper T cells.

Identify the type of T cells that interact with MHC II: Helper T cells, which have CD4 markers, recognize antigens presented by MHC II molecules.

Clarify the function of CD4 T cells: CD4 T cells, also known as helper T cells, do not kill cells directly. Instead, they activate other immune cells, including APCs, to enhance the immune response.

Differentiate between CD4 and CD8 T cells: CD8 T cells, also known as cytotoxic T cells, interact with MHC I molecules and are responsible for killing infected or cancerous cells.

Conclude the correct interaction: When an MHC II molecule on an APC presents an antigen, effector cells with CD4 markers (helper T cells) activate the APC, enhancing the immune response.