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

Previous problemNext problem

Problem 8

Textbook Question

Which of the following functions is/are performed by complement proteins?
a. Cell lysis
b. Opsonization
c. Enhancing inflammation
d. Only a and b
e. All of the above

Verified step by step guidance

Step 1: Understand the role of complement proteins in the immune system. Complement proteins are part of the innate immune system and help defend the body against pathogens by enhancing various immune responses.

Step 2: Define the term 'cell lysis.' Complement proteins can form a membrane attack complex (MAC) that creates pores in the membranes of pathogens, leading to their destruction through cell lysis.

Step 3: Define 'opsonization.' Complement proteins can coat the surface of pathogens, making them easier for phagocytes (like macrophages) to recognize and engulf. This process is called opsonization.

Step 4: Explain how complement proteins enhance inflammation. Complement proteins can stimulate the release of inflammatory mediators, such as histamine, which increases blood flow and attracts immune cells to the site of infection.

Step 5: Evaluate the options provided in the question. Since complement proteins perform all three functions (cell lysis, opsonization, and enhancing inflammation), the correct answer would include all of the above functions.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Play a video:

Was this helpful?

Key Concepts

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

Complement System

The complement system is a part of the immune system consisting of proteins that enhance the ability of antibodies and phagocytic cells to clear pathogens from an organism. It plays a crucial role in immune responses, including opsonization, cell lysis, and inflammation. Understanding how these proteins function helps in grasping their importance in both innate and adaptive immunity.

Opsonization

Opsonization is a process where pathogens are marked for destruction by immune cells. Complement proteins bind to the surface of pathogens, making them more recognizable to phagocytes like macrophages and neutrophils. This enhances the efficiency of the immune response, allowing for quicker and more effective clearance of infections.

Cell Lysis

Cell lysis refers to the destruction of a cell's membrane, leading to its death. In the context of the complement system, certain complement proteins form a membrane attack complex that creates pores in the target cell's membrane, causing it to burst. This mechanism is particularly effective against bacteria and is a key function of the complement system in combating infections.