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

First-Line Defenses: Chemical Barriers

Anatomy & Physiology

21. The Immune System

First-Line Defenses: Chemical Barriers

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3:40 minutes

Problem 16

Textbook Question

Interferons are referred to as antiviral proteins. What stimulates their production, and how do they protect uninfected cells?

Verified step by step guidance

Understand that interferons are a type of cytokine, which are signaling proteins produced by cells in response to specific stimuli, particularly viral infections.

Recognize that the production of interferons is stimulated when a cell detects the presence of viral components, such as double-stranded RNA or viral proteins, which are foreign to the host cell.

Learn that once produced, interferons bind to receptors on neighboring uninfected cells, triggering a signaling cascade that activates antiviral defense mechanisms within those cells.

Explore how interferons stimulate the production of antiviral proteins, such as protein kinase R (PKR), which inhibits viral replication by interfering with the translation of viral RNA.

Understand that interferons also enhance the activity of immune cells, such as natural killer (NK) cells and macrophages, to destroy infected cells and prevent the spread of the virus.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Interferons

Interferons are a group of signaling proteins produced by host cells in response to viral infections. They play a crucial role in the immune response by signaling neighboring cells to enhance their antiviral defenses. There are three main types: Type I (e.g., IFN-alpha and IFN-beta), Type II (IFN-gamma), and Type III (IFN-lambda), each with distinct functions in immune regulation.

Stimuli for Interferon Production

The production of interferons is primarily stimulated by the presence of viral components, such as double-stranded RNA, which is often produced during viral replication. Other stimuli include certain cytokines and pathogen-associated molecular patterns (PAMPs) recognized by pattern recognition receptors (PRRs) on host cells. This recognition triggers signaling pathways that lead to the transcription of interferon genes.

Mechanism of Action

Interferons protect uninfected cells by binding to specific receptors on their surface, initiating a signaling cascade that activates genes responsible for antiviral defenses. This results in the production of proteins that inhibit viral replication, enhance the immune response, and promote apoptosis in infected cells. Consequently, interferons create an antiviral state in neighboring cells, limiting the spread of the virus.