Biology Chapter 21: Immune System Flashcards

Questions and Answers

The immune response is a short-term response to a specific pathogen.

True

The immune response is an innate response rather than acquired.

False

Which type of immunity is produced by an individual after either natural exposure to the antigen or after immunization against the antigen?

Passive acquired immunity

Active acquired immunity (correct)

Passive innate immunity

Active innate immunity

What type of immunity is produced when an immunoglobulin crosses the placenta?

Passive acquired immunity Signup and view all the answers

Where are antibodies produced?

In plasma cells Signup and view all the answers

Which immunoglobulin is present in blood, saliva, breast milk, and respiratory secretions?

Immunoglobulin G (IgG) Signup and view all the answers

Which antibody is found in the blood to indicate a typical primary immune response?

IgM Signup and view all the answers

If a person had very low levels of Ig__, he or she may be more susceptible to infections of mucous membranes.

A Signup and view all the answers

When a person is exposed to most antigens, how long does it take before an antibody can be detected in the circulation?

3-6 days Signup and view all the answers

How do antibodies protect the host from bacterial toxins?

By binding to the toxins to neutralize their biologic effects Signup and view all the answers

Which T cell controls or limits the immune response to protect the host's own tissues against an autoimmune response?

Helper 1 (Th1) cells Signup and view all the answers

At birth, samples of blood from the umbilical cord indicate which immunoglobulin levels, if any, are near adult levels?

Immunoglobulin G (IgG) Signup and view all the answers

What is the first line of defense in the immune system?

skin and mucous membranes Signup and view all the answers

What is the second line of defense in the immune system?

inflammatory response Signup and view all the answers

What is the adaptive defense system also known as?

immune response Signup and view all the answers

What are small proteins secreted by virus-infected cells called?

interferons Signup and view all the answers

What major innate mechanism mediates the destruction of foreign substances in the body?

complement Signup and view all the answers

Which cells stimulate the proliferation of other lymphocytes?

helper T cells Signup and view all the answers

Which cells decrease the activity of both T cells and B cells?

regulatory T cells Signup and view all the answers

What cells present antigens to activate T cells?

APC's (Antigen-Presenting Cells) Signup and view all the answers

What is the main antibody of both primary and secondary immune responses?

IgG Signup and view all the answers

Which antibody protects mucosal barriers?

IgA Signup and view all the answers

Which antibody is involved in allergies?

IgE Signup and view all the answers

What is the antibody that, along with IgM, serves as a B cell receptor?

IgD Signup and view all the answers

Which of the following is associated with passive immunity?

Passage of IgG antibodies from a pregnant mother to her fetus Signup and view all the answers

Which of the following is a type of T cell?

Cytotoxic Signup and view all the answers

B lymphocytes develop immunocompetence in the:

Bone marrow Signup and view all the answers

Which of the following is not a function of the inflammatory response?

Replaces injured tissue with connective tissue Signup and view all the answers

The redness and heat of an inflamed area are due to a local hyperemia caused by:

Vasodilation Signup and view all the answers

In clonal selection of B cells, which substance is responsible for determining which cells will eventually become cloned?

Antigen Signup and view all the answers

The process whereby neutrophils and other white blood cells are attracted to an inflammatory site is called:

Chemotaxis Signup and view all the answers

Small molecules that bind with self-proteins to produce antigenic substances are called:

Haptens Signup and view all the answers

The only T cells that can directly attach and kill other cells are the:

Cytotoxic cells Signup and view all the answers

Select the correct statement about phagocytic cells.

Neutrophils are the first phagocytes at an injury site Signup and view all the answers

_______ predominate at the sites of chronic infection.

Macrophages Signup and view all the answers

Interferons:

Interfere with viral replication within cells Signup and view all the answers

Select the correct statement about regulatory T cells.

May function in preventing autoimmune diseases Signup and view all the answers

Select the correct definition about tissue grafts.

Isografts are between identical twins Signup and view all the answers

The only immunoglobulin to exist as a pentamer is:

IgM Signup and view all the answers

_______ are released by activated T cells and macrophages to mobilize immune cells.

Cytokines Signup and view all the answers

B cells respond to the initial antigen challenge by:

Producing progeny cells that include plasma cells and memory cells Signup and view all the answers

Cancer cells and virus-infected body cells can be killed before the activation of adaptive immunity by:

Natural killer cells Signup and view all the answers

Complement proteins and antibodies coat a microorganism, enabling macrophages and neutrophils to phagocytize the organism. This phenomenon is termed:

Opsonization Signup and view all the answers

Which of the following is not characteristic of the adaptive immune system?

It is non-specific Signup and view all the answers

Which of the following would be classified as a delayed hypersensitivity reaction?

Allergic contact dermatitis Signup and view all the answers

Innate immune system defenses include:

Phagocytosis Signup and view all the answers

Select the correct statement about inflammation.

Exudate is the cause of localized edema Signup and view all the answers

Phagocyte mobilization involves:

Mainly neutrophil and macrophage migration into inflamed areas Signup and view all the answers

Fever:

Production is regulated by chemicals called pyrogens Signup and view all the answers

Immunocompetence:

Is the ability of individual cells to recognize a specific antigen Signup and view all the answers

Select the correct statement about the prevention of an immune attack on 'self.'

Tolerance to self is developed during fetal development Signup and view all the answers

Select the correct statement about active and passive immunity.

Active and passive immunity are both mechanisms of specific immunity Signup and view all the answers

Cytotoxic T cells:

Are the only T cells that can directly attack and kill other cells Signup and view all the answers

Helper T cells:

Function in adaptive immunity activation Signup and view all the answers

Select the correct statement about immunodeficiency.

The causative agent in AIDS is a virus that recognizes helper T cells Signup and view all the answers

Natural killer (NK) cells:

Are a type of lymphocyte Signup and view all the answers

Clonal selection of B cells:

Results in the formation of plasma cells Signup and view all the answers

The primary immune response:

Has a lag period while B cells proliferate Signup and view all the answers

Which of the following is not an autoimmune disease?

Type II diabetes Signup and view all the answers

Select the correct statement about complement.

Complement may be directed to its target by an adaptive immune mechanism Signup and view all the answers

Which secretion provides antibacterial and antifungal fatty acids and lactic acid?

Sebaceous glands Signup and view all the answers

What process causes edema during the inflammatory process?

Endothelial cell contraction Signup and view all the answers

What process causes heat and redness during the inflammatory process?

Vasodilation Signup and view all the answers

What is a vascular effect of histamine released from mast cells?

Vasodilation Signup and view all the answers

What is an outcome of the complement cascade?

Attacks bacterial cell membranes Signup and view all the answers

Which chemical mediators induce pain during an inflammatory response?

Prostaglandins and bradykinin Signup and view all the answers

What effect does chemotactic factor have on the inflammatory process?

It directs leukocytes to the inflamed area Signup and view all the answers

When looking at white blood cell differentials, which leukocyte indicates early, acute inflammatory reactions?

Neutrophils Signup and view all the answers

The predominant phagocytic cells in later stages of an inflammatory response are:

Macrophages Signup and view all the answers

Which cells are responsible for presenting the antigen to immune cells during clonal selection?

Antigen-processing cells Signup and view all the answers

Both B and T cells are originally derived from cells of the:

Bone marrow Signup and view all the answers

The immunoglobulin that crosses the placenta confers _____ immunity to the fetus.

Passive acquired Signup and view all the answers

A 16-year-old male bitten by a rabid dog is given _____ to prevent infection.

Immunoglobulins Signup and view all the answers

The most abundant class of antibody in the blood is:

IgG Signup and view all the answers

The predominant antibody of a typical primary immune response is:

IgM Signup and view all the answers

The primary role of secretory IgA is to prevent infections in:

Mucous membranes Signup and view all the answers

Histocompatibility antigens help the immune system:

Distinguish self from nonself Signup and view all the answers

A 20-year-old female diagnosed with AIDS would reveal diminished levels of:

Helper T cells Signup and view all the answers

After exposure to a specific antigen, B cells differentiate into:

Plasma cells Signup and view all the answers

What are primary characteristics that differentiate the immune response?

The immune response is specific to the antigen Signup and view all the answers

Study Notes

Immune System Overview

The immune system has two main defensive lines: non-specific (first line) and specific (adaptive immune response).
First Line of Defense: Skin and mucous membranes act as barriers to pathogens.
Second Line of Defense: Inflammatory response promotes the production of white blood cells to combat tissue damage.

Key Proteins and Cells

Interferons: Small proteins secreted by virus-infected cells to inhibit viral replication in neighboring cells.
Complement System: Major innate mechanism that aids in the destruction of foreign substances.
Helper T Cells: Stimulate the proliferation of other lymphocytes and enhance immune response.
Regulatory T Cells: Decrease the activity of T cells and B cells, preventing overactive immune responses.

Antigens and Antibodies

APCs (Antigen-Presenting Cells): Present antigens to activate T cells.
Immunoglobulin G (IgG): Main antibody in both primary and secondary immune responses.
Immunoglobulin A (IgA): Protects mucosal surfaces by preventing pathogen entry.
Immunoglobulin E (IgE): Involved in allergic reactions.
Immunoglobulin D (IgD): Functions as a B cell receptor, alongside IgM.
Immunoglobulin M (IgM): Activates complement and is the first antibody produced during an immune response.

Immunity Concepts

Passive Immunity: Primarily involves the transfer of antibodies (e.g., IgG from mother to fetus).
T Cells: Include cytotoxic, helper, and regulatory types, critical for adaptive immunity.
B Cells: Develop immunocompetence in the bone marrow; differentiate into plasma cells to produce antibodies upon activation.

Inflammation and Immune Response

Inflammatory Response: Involves vasodilation, increased permeability, and attracts phagocytes to the injury site.
Chemotaxis: Process where leukocytes are directed to inflammation sites.
Fever: Regulated by pyrogens, indicates an immune response and helps inhibit bacterial replication.

Immune Deficiencies and Disorders

AIDS: Characterized by lower levels of helper T cells, leading to reduced immune response.
Clonal Selection: B cells undergo clonal selection upon encountering specific antigens, resulting in the creation of plasma cells.

Additional Key Points

Opsonization: The process where antibodies and complement proteins coat pathogens for enhancement of phagocytosis.
Autoimmunity: Results from producing antibodies against one's own tissues, as seen in diseases like multiple sclerosis and lupus.
Histocompatibility Antigens: Help differentiate self from non-self, crucial in immune responses and organ transplants.
Active vs. Passive Immunity: Active immunity develops after exposure to antigens, while passive immunity involves the transfer of antibodies.

Antibody Production

Antibodies are produced in plasma cells, derived from activated B cells.
IgA is prevalent in mucosal secretions, providing localized immunity.
IgM indicates a primary immune response, while IgG indicates memory and secondary response capabilities.

Summary of Mechanisms

Complement Activation: Triggered through classical, alternative, or lectin pathways leading to pathogen lysis.
Phagocyte Mobilization: Involves diapedesis and margination, facilitating white blood cell movement to sites of injury.
Antigen Recognition: Mediated by specific receptors on B and T cells, essential for initiating immune responses.

These notes cover essential functions, pathways, and components of the immune system, providing a comprehensive overview for study and understanding.

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Test your knowledge on the immune system with these flashcards from Chapter 21. This quiz covers key concepts like the first and second lines of defense and the adaptive defense system. Perfect for students studying biology and immunology.