Table of contents

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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

First-Line Defenses: Chemical Barriers

Anatomy & Physiology

21. The Immune System

First-Line Defenses: Chemical Barriers

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Multiple Choice

Which of the following is/are secreted by leukocytes and macrophages and result(s) in a fever?

histamine

pyrogens

keratin

heparin

antibodies

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Identify the role of leukocytes and macrophages in the immune response. Leukocytes, or white blood cells, and macrophages are key players in the body's defense mechanism against infections.

Understand the concept of fever as a physiological response. Fever is a common response to infection, where the body's temperature is elevated to help fight off pathogens.

Learn about pyrogens, which are substances that can induce fever. Pyrogens are typically released by leukocytes and macrophages in response to infection.

Differentiate between the substances listed in the problem: histamine, keratin, heparin, and antibodies. Recognize that pyrogens are specifically involved in the fever response.

Conclude that pyrogens are the substances secreted by leukocytes and macrophages that result in a fever, as they act on the hypothalamus to increase body temperature.