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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 Heart2h 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

Introduction to the Immune System

21. The Immune System

Introduction to the Immune System: Videos & Practice Problems

Video Lessons Practice Worksheet

Topic summary

Immunity is the body's ability to eliminate disease-causing microbes, divided into innate (nonspecific) and adaptive (specific) immunity. Innate immunity provides routine protection from various pathogens at birth, utilizing physical barriers like skin and chemical defenses. Adaptive immunity evolves over time, targeting specific pathogens through antibodies and specialized cells like B and T cells. Antigens, foreign substances that trigger immune responses, interact with antibodies, which are Y-shaped proteins that bind to these antigens, facilitating pathogen elimination. Understanding these mechanisms is crucial for comprehending how the immune system functions.

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Introduction to Immunity

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Introduction to Immunity Video Summary

Immunity is the body's ability to eliminate disease-causing microbes and protect against environmental agents, such as pollen. It is essential to understand that immunity can be categorized into two main types: innate immunity and adaptive immunity. Innate immunity, also known as nonspecific immunity, provides routine protection that is present at birth. This type of immunity acts against a broad range of pathogens without the need for prior exposure. Key components of innate immunity include physical barriers like skin and mucous membranes, as well as chemical defenses such as antimicrobial substances and acids.

On the other hand, adaptive immunity, or specific immunity, develops over time and is tailored to respond to specific pathogens. This type of immunity is characterized by its ability to adapt and improve its response based on previous encounters with various environmental agents. Adaptive immunity involves the production of antibodies—Y-shaped proteins that bind to foreign molecules—and the activation of specialized immune cells, including B cells and T cells. These components work together to provide targeted protection against specific pathogens.

While innate and adaptive immunity are often discussed separately, it is important to note that they can complement each other. Certain aspects of innate immunity can enhance the effectiveness of adaptive responses, and vice versa. As you continue to study immunity, keep in mind the interplay between these two systems, as they collectively contribute to the body's defense mechanisms against infections and diseases.

Problem

Factors that work generically against any foreign substance entering the host are described as:

Innate immunity.

Specific immunity.

Irregular immunity.

Immune metabolism.

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Antigens & Antibodies

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Antigens & Antibodies Video Summary

Antigens and antibodies are crucial components of the immune system, particularly in the context of adaptive immunity, which is also known as specific immunity. An antigen is any substance, often a toxin or foreign microbe, that can provoke an immune response by inducing the production of antibodies. Antibodies, which are Y-shaped proteins, specifically recognize and bind to these antigens through their two antigen-binding sites.

When an antibody binds to an antigen, it can trigger various immune responses. For instance, the binding can facilitate the targeting and elimination of pathogens, such as bacteria or viruses, by immune cells. This process often involves the release of specific chemicals that help destroy the pathogen. The interaction between antibodies and antigens is fundamental to the body's ability to defend itself against disease-causing agents.

As we delve deeper into the study of immunity, we will explore the different types of immune responses that antibodies can generate and their significant role in protecting the body from infections. Understanding the mechanisms of how antibodies function will enhance our comprehension of adaptive immunity and its importance in health and disease.

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What is the difference between innate and adaptive immunity?

Innate immunity, also known as nonspecific immunity, provides routine protection from a broad range of pathogens and is present at birth. It includes physical barriers like skin and mucous membranes, as well as chemical defenses such as antimicrobials and acids. Adaptive immunity, or specific immunity, evolves over time and targets specific pathogens. It involves specialized cells like B cells and T cells, and antibodies that bind to antigens to facilitate pathogen elimination. While innate immunity offers immediate defense, adaptive immunity provides a more tailored response that improves with exposure to different pathogens.

How do antibodies function in the immune system?

Antibodies are Y-shaped proteins that play a crucial role in adaptive immunity. They recognize and bind to specific antigens, which are foreign substances like toxins or microbes. Once bound, antibodies can trigger various immune responses, such as marking the pathogen for destruction by immune cells. For example, an antibody can bind to an antigen on a pathogen's surface, signaling immune cells to attack and eliminate the pathogen. This process helps the body to effectively target and neutralize specific threats, enhancing the overall immune response.

What are the main components of innate immunity?

Innate immunity consists of several key components that provide immediate defense against a wide range of pathogens. These include physical barriers like the skin and mucous membranes, which prevent pathogen entry. Chemical defenses such as antimicrobial peptides, acids, and enzymes also play a role in neutralizing invaders. Additionally, innate immunity involves various immune cells like macrophages, neutrophils, and natural killer cells, which can quickly respond to and eliminate pathogens. These components work together to offer a broad, nonspecific defense that is present from birth.

What role do B cells and T cells play in adaptive immunity?

B cells and T cells are essential components of adaptive immunity. B cells are responsible for producing antibodies that bind to specific antigens, marking pathogens for destruction. They can also differentiate into memory B cells, which provide long-term immunity by remembering past infections. T cells, on the other hand, come in two main types: helper T cells and cytotoxic T cells. Helper T cells assist in activating B cells and other immune cells, while cytotoxic T cells directly attack and destroy infected cells. Together, B cells and T cells provide a targeted and adaptable immune response.

What are antigens and how do they trigger an immune response?

Antigens are foreign substances, such as toxins or microbes, that can induce an immune response. When an antigen enters the body, it is recognized by antibodies, which are Y-shaped proteins that bind specifically to the antigen. This binding can trigger various immune responses, such as marking the pathogen for destruction by immune cells. For example, an antibody-antigen complex can signal macrophages to engulf and destroy the pathogen. This process helps the immune system to effectively target and eliminate specific threats, ensuring a precise and efficient defense.