Immunology & Immune System Intro

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Questions and Answers

What is the primary function of the immune system?

To produce energy for the body

To facilitate digestion

To regulate hormone levels (correct)

To recognize and destroy foreign materials (correct)

Which of the following is NOT a part of the innate immune system?

Sweat

Tears

Lymphocytes (correct)

Skin

Which organs are classified as primary lymphoid organs?

Thymus and bone marrow (correct)

Appendix and Peyer’s patches

Lymph nodes and spleen

Tonsils and tissue lymphatics

Which type of immunity is characterized as nonspecific?

Innate immunity Signup and view all the answers

What role do cytokines play in the immune response?

They facilitate communication between immune cells Signup and view all the answers

How does sweat contribute to the immune system?

By containing chemicals that kill pathogens Signup and view all the answers

Which of the following structures is considered a secondary lymphoid organ?

Spleen Signup and view all the answers

What is the main component of the body's first line of defense against pathogens?

Physical and chemical barriers Signup and view all the answers

What characterizes active immunity?

It requires a latent period for immune response activation. Signup and view all the answers

Which statement accurately describes passive immunity?

It relies on the introduction of pre-formed antibodies. Signup and view all the answers

What is an antigen?

A substance that specifically binds an antibody or T cell receptor. Signup and view all the answers

What makes each species chemically and antigenically unique?

Differences in its proteins, carbohydrates, and other organic substances. Signup and view all the answers

What are antigenic determinants also known as?

Epitopes. Signup and view all the answers

Which of the following is NOT a common source of antigens?

Conjugated vaccines. Signup and view all the answers

What is the main function of an antigen in the immune system?

To stimulate an immune response. Signup and view all the answers

How do antigenic determinants relate to the immune response?

They serve as specific targets for immune cells. Signup and view all the answers

What type of antigens are derived from a person's own tissues?

Autoantigens Signup and view all the answers

Which immunoglobulin is primarily associated with immediate allergic reactions?

Immunoglobulin E (IgE) Signup and view all the answers

What is the function of antibodies in the humoral immune response?

They recognize and bind to specific antigens. Signup and view all the answers

What initiates the production of antibodies during the immune response?

B-lymphocytes Signup and view all the answers

Which type of immune response is mediated by helper T-lymphocytes?

Both humoral and cellular immune responses Signup and view all the answers

What determines the effectiveness of the immune response?

The site of infection and type of pathogen Signup and view all the answers

What role do cytotoxic T-lymphocytes play in the immune system?

They kill infected or foreign cells. Signup and view all the answers

Which immunoglobulin is found in mucosal areas and is responsible for mucosal immunity?

Immunoglobulin A (IgA) Signup and view all the answers

What characterizes passive immunization?

It involves the administration of preformed antibodies. Signup and view all the answers

What is a primary cause of autoimmunity?

Loss of self-tolerance. Signup and view all the answers

Which of the following is NOT one of the four types of hypersensitivity reactions?

Type V Signup and view all the answers

What are immunodeficiencies?

Defects in components of the immune system. Signup and view all the answers

What is the primary indication of hypersensitivity diseases?

An abnormal immune reaction occurs upon subsequent exposure to an antigen. Signup and view all the answers

How many types of hypersensitivity reactions are there?

Four types Signup and view all the answers

Which statement about active immunization is accurate?

It provides long-term protection through antigen exposure. Signup and view all the answers

Which of the following best explains hypersensitivity reactions?

They occur due to an overreaction to harmless antigens. Signup and view all the answers

What role does mucus play in the body's defense mechanisms?

It traps pathogens which can then be expelled or destroyed. Signup and view all the answers

Which of the following is NOT a characteristic of the inflammatory response?

Production of specialized antibodies. Signup and view all the answers

How does the immune system differ from the first and second lines of defense?

It recognizes and remembers specific pathogens. Signup and view all the answers

What is active immunity?

Immunity acquired through vaccination and infection. Signup and view all the answers

What primarily causes redness and heat during an inflammatory response?

Capillary dilation resulting in increased blood flow. Signup and view all the answers

What is the main purpose of lysozyme found in saliva?

To kill bacteria by breaking their cell walls. Signup and view all the answers

What happens to plasma during inflammation?

It leaks into damaged tissue causing swelling. Signup and view all the answers

What defines the adaptive immunity?

Response to a specific antigen with memory. Signup and view all the answers

Study Notes

Overview of the Immune System

The immune system includes all body parts that recognize and destroy foreign materials, comprising white blood cells, phagocytes, lymphocytes, bone marrow, lymph nodes, tonsils, thymus, and spleen.
Immunity provides protection against infections via a coordinated immune response involving various cells, tissues, and molecules.

Classification of Immune System Organs

Primary Lymphoid Organs: Thymus and bone marrow are essential for developing immune cells.
Secondary Lymphoid Organs: Includes tonsils, lymph nodes, spleen, Peyer’s patches, appendix, and tissue lymphatics where immune responses are initiated.

Types of Immunity

Innate (Non-Specific) Immunity:
- First-Line Defenses: Includes physical and chemical barriers like skin, sweat, tears, saliva, mucus, and stomach acid that act as the body’s initial defenses against pathogens.
- Second-Line Defenses: Involves the inflammatory response characterized by redness, heat, swelling, and pain upon pathogen invasion.
Adaptive (Specific) Immunity:
- Involves antigen-specific immune responses, producing specialized cells and antibodies that destroy pathogens, with memory for faster response during re-exposure.

Active vs. Passive Immunity

Active Immunity: Develops resistance through active engagement of the immune system in response to an antigenic stimulus, involving the production of antibodies over time.
Passive Immunity: Involves transfer of pre-formed antibodies without engaging the recipient's immune response, offering immediate but temporary protection.

Antigens and Antibodies

Antigen: Foreign substances that specifically bind to antibodies or T cell receptors, triggering an immune response; common antigens include proteins and polysaccharides.
Types of Antigens: Autoantigens (self), alloantigens (from other individuals of the same species), and heterophile antigens (identical antigens across different species).
Antibody (Immunoglobulin): A protein produced by B cells that binds specifically to antigens; classified into IgM, IgG, IgA, IgD, and IgE.

Immune Response Mechanisms

Humoral Immunity: Involves antibodies secreted by B cells that bind to antigens.
Cellular Immunity: Mediated by cytotoxic T lymphocytes that destroy infected cells and helper T cells that assist B cells and T cells in responding.

Immunization Strategies

Passive Immunization: Administration of pre-formed antibodies for immediate protection.
Active Immunization: Vaccination with microbes or their antigens to induce an immunological response enabling future protection.

Disorders of the Immune System

Hypersensitivity Reactions: Over-reactions of the adaptive immune response to harmless antigens, categorized into four types.
Autoimmunity: Misdirected immune response leading to damage of self-tissues due to loss of self-tolerance; consists of three types of reactions.
Immunodeficiencies: Result from absent or defective components of the immune system, with genetic or acquired causes.

Hypersensitivity Diseases

Definition: Abnormal immune responses upon re-exposure to previously encountered antigens.
Types of Hypersensitivity: Identified by their pathogenesis and resulting clinical manifestations; the terminology prefers descriptive terms over numerical classification.

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Description

This quiz covers the fundamental concepts of immunology and the immune system. It explores the roles of various components such as white blood cells, phagocytes, and lymphocytes in recognizing and combating foreign materials. Test your knowledge on how the body defends itself against infections.