Immunology Overview 2
44 Questions
6 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary role of the Fas molecule in the action of cytotoxic T cells?

  • To increase the binding affinity to antigens
  • To promote the differentiation of B cells
  • To enhance the granule exocytosis process
  • To initiate apoptosis in infected cells (correct)

Which of the following describes a function of antibodies?

  • Neutralize toxins and prevent their effects (correct)
  • Inhibit the production of plasma cells
  • Enhance infection by promoting antigen recognition
  • Clump pathogens to enhance their spread

What characteristic of antibodies allows them to attach specifically to different pathogens?

  • The shape of the Y-structure
  • The variable region of the antibody (correct)
  • The fixed region of the antibody
  • The molecular weight of the antibody

What is the process by which cytotoxic T cells destroy infected cells called?

<p>Granule exocytosis (C)</p> Signup and view all the answers

What molecules do plasma cells produce to combat pathogens?

<p>Antibodies (A)</p> Signup and view all the answers

How do antibodies function as opsonins?

<p>They enhance the recognition of pathogens by immune cells. (A)</p> Signup and view all the answers

What is one mechanism by which antibodies can stop viral infections?

<p>By binding to viral receptors and blocking cell recognition (C)</p> Signup and view all the answers

Which component of the antibody structure is recognized by many cells in the immune system?

<p>Fixed region (B)</p> Signup and view all the answers

What is the end result of granul exocytosis performed by a cytotoxic T cell?

<p>Cell lysis and death of the infected cell (A)</p> Signup and view all the answers

Which of the following pathways trigger the complement system?

<p>The Classical pathway (D)</p> Signup and view all the answers

What is the primary function of opsonins in the complement cascade?

<p>To enhance the ability of phagocytes to engulf pathogens (D)</p> Signup and view all the answers

Where are B cells primarily stored in the body?

<p>In the mucosa-associated lymphoid tissue (B)</p> Signup and view all the answers

How are T cells specifically activated during an immune response?

<p>By the interaction with dendritic cells that present antigens (A)</p> Signup and view all the answers

Which complement protein is involved in initiating the complement cascade?

<p>C1 (A)</p> Signup and view all the answers

What is the main role of dendritic cells in the adaptive immune response?

<p>Alerting the appropriate T and B cells during infection (C)</p> Signup and view all the answers

Which of the following correctly describes T cell receptors?

<p>They are specific to a single type of antigen (C)</p> Signup and view all the answers

What is a consequence of the complement cascade triggering inflammation?

<p>Enhanced ability of the immune system to respond to pathogens (C)</p> Signup and view all the answers

What is one key characteristic of B cells?

<p>They primarily reside in mucosa-associated lymphoid tissue (D)</p> Signup and view all the answers

Which complement protein is most associated with forming the membrane attack complex?

<p>C9 (D)</p> Signup and view all the answers

What do T helper cells release to facilitate the activation of B cells?

<p>Cytokines. (A)</p> Signup and view all the answers

Which cells are responsible for killing infected cells in the immune response?

<p>Cytotoxic T cells. (C)</p> Signup and view all the answers

How do dendritic cells initiate the adaptive immune response?

<p>By presenting antigens to CD4 T cells. (C)</p> Signup and view all the answers

What is the function of memory B cells in the immune system?

<p>To provide long-term immunity and quicker responses to future infections. (B)</p> Signup and view all the answers

What mechanism do cytotoxic T cells use to recognize infected cells?

<p>Binding to HLA class I molecules displaying specific antigens. (B)</p> Signup and view all the answers

Which cell type acts as a bridge between the innate and adaptive immune systems?

<p>Dendritic cells. (D)</p> Signup and view all the answers

What role do cytokines play in the immune response?

<p>They act as chemical signals to regulate immune functions. (C)</p> Signup and view all the answers

What distinguishes T helper cells from cytotoxic T cells?

<p>T helper cells activate other cells, while cytotoxic T cells kill infected cells. (D)</p> Signup and view all the answers

Which of the following statements is true regarding dendritic cells?

<p>They play a crucial role in antigen presentation. (D)</p> Signup and view all the answers

What is a consequence of cytokine release during the inflammatory response?

<p>Vasodilation of blood vessels (B)</p> Signup and view all the answers

Which process is primarily responsible for marking pathogens for phagocytosis?

<p>Opsonization by opsonins (B)</p> Signup and view all the answers

What systemic effect is caused by interleukins during an inflammatory response?

<p>Fever development (B)</p> Signup and view all the answers

How does the acute phase response affect the liver?

<p>It enhances production of acute-phase proteins like opsonins. (A)</p> Signup and view all the answers

Which of the following is a primary role of macrophages during the inflammatory response?

<p>To recruit other immune cells and destroy pathogens (C)</p> Signup and view all the answers

What is the role of C-reactive protein (CRP) in measuring inflammation?

<p>CRP indicates the severity of inflammation. (C)</p> Signup and view all the answers

What is the role of macrophages in the initial immune response?

<p>They release signaling proteins to activate T &amp; B cells. (C), They phagocytose pathogens directly after recognition. (D)</p> Signup and view all the answers

What are Pathogen-Associated Molecular Patterns (PAMPs)?

<p>Unique characteristics recognized by innate immune cells. (B)</p> Signup and view all the answers

Which process is primarily associated with the immediate response of the innate immune system?

<p>Phagocytosis and secretion of cytokines. (B)</p> Signup and view all the answers

How do dendritic cells activate the adaptive immune system?

<p>By transporting antigens to T &amp; B cells via the bloodstream. (B)</p> Signup and view all the answers

What are the two main categories of immune responses?

<p>Innate and Adaptive (A)</p> Signup and view all the answers

Which of the following statements is true regarding innate immune responses?

<p>They provide immediate but non-specific responses. (D)</p> Signup and view all the answers

What distinguishes adaptive immune responses from innate responses?

<p>They involve T &amp; B cells and generate long-term immunity. (D)</p> Signup and view all the answers

Which of the following is primarily a physical barrier of the innate immune system?

<p>Skin (A)</p> Signup and view all the answers

What is the purpose of chemical barriers like low pH in the stomach?

<p>To kill or inhibit pathogen growth. (B)</p> Signup and view all the answers

What triggers the activation of the adaptive immune response?

<p>Arrival of antigens at T &amp; B cells. (A)</p> Signup and view all the answers

Flashcards

Cytotoxic T cell action

Cytotoxic T cells destroy infected cells by releasing enzymes or activating apoptosis pathways.

Granul Exocytosis

A method of cytotoxic T cell action where enzymes destroy infected cell membranes, leading to cell death.

Fas Molecule Activation

A method of cytotoxic T cell action triggering apoptosis (programmed cell death) in the infected cells.

Plasma cell

A differentiated B cell that produces large amounts of antibodies.

Signup and view all the flashcards

Antibody structure

Y-shaped protein with variable regions that match antigens and fixed regions recognized by immune cells.

Signup and view all the flashcards

Antibody function: Agglutination

Antibodies clump pathogens, slowing spread.

Signup and view all the flashcards

Antibody function: Opsonization

Antibodies help immune cells recognize pathogens, aiding phagocytes.

Signup and view all the flashcards

Antibody function: Toxin neutralization

Antibodies bind to toxins, rendering them harmless.

Signup and view all the flashcards

Antibody function: Blocking pathogen function

Antibodies bind to virus or bacteria receptors, preventing them from infecting cells.

Signup and view all the flashcards

Complement System

A part of the immune system that helps destroy pathogens, working with innate and adaptive immunity.

Signup and view all the flashcards

Complement Cascade

A series of complement protein activations that leads to the destruction of pathogens.

Signup and view all the flashcards

Opsonins

Complement system products that mark pathogens for destruction by phagocytes.

Signup and view all the flashcards

Lectin Pathway

One way the complement system is triggered.

Signup and view all the flashcards

Alternative Pathway

Another way to trigger the complement system, not antibody-dependent.

Signup and view all the flashcards

Classical Pathway

The complement system activation that starts with antibodies.

Signup and view all the flashcards

B-cells

Lymphocytes that produce antibodies, part of the adaptive immune response.

Signup and view all the flashcards

T-cells

Lymphocytes that have receptors to recognize specific antigens, part of the adaptive immune response.

Signup and view all the flashcards

Dendritic cells

Immune cells that alert the right T & B cells to fight infection.

Signup and view all the flashcards

Antibodies

Proteins that bind to specific antigens (pathogens, toxins).

Signup and view all the flashcards

Innate Immunity

The body's first line of defense against pathogens. It's a rapid, non-specific response that acts immediately upon infection.

Signup and view all the flashcards

Adaptive Immunity

The body's specific defense system. It targets specific pathogens and develops a memory for future encounters.

Signup and view all the flashcards

Physical Barriers

The first line of defense in innate immunity. They prevent pathogens from entering the body. Examples include skin, respiratory tract lining, and the gastrointestinal tract lining.

Signup and view all the flashcards

Chemical Barriers

The second line of defense in innate immunity. They use chemicals to fight pathogens. Examples include stomach acid, lysozyme in tears and saliva, and lactic acid in the vagina.

Signup and view all the flashcards

Pathogen-Associated Molecular Patterns (PAMPs)

Molecular patterns recognized by the innate immune system. These patterns are unique to pathogens and are not found in healthy human cells.

Signup and view all the flashcards

Macrophage

A type of white blood cell that acts as the first responder in the innate immune system. They engulf and destroy pathogens (phagocytosis).

Signup and view all the flashcards

Cytokines

Signaling proteins released by macrophages and other immune cells. They help coordinate the immune response by activating other cells.

Signup and view all the flashcards

Initial Immune Response

The sequence of events that occur when a pathogen enters the body. It involves the innate immune system initially, followed by the activation of the adaptive immune system.

Signup and view all the flashcards

Why is the adaptive immune response slower than the innate immune response?

The adaptive immune response takes longer to activate because it needs to identify specific antigens and produce specialized immune cells (T and B cells) to target them.

Signup and view all the flashcards

Antigen Presentation

The process where dendritic cells display antigens on their surface to T and B cells, triggering an immune response.

Signup and view all the flashcards

T Helper Cell

A type of T cell that helps activate other immune cells, including cytotoxic T cells and B cells, to fight infection.

Signup and view all the flashcards

Cytotoxic T Cell

A type of T cell that directly kills infected cells by releasing enzymes or inducing apoptosis.

Signup and view all the flashcards

Memory B Cell

A long-lived B cell that remembers specific antigens, allowing for a faster immune response upon re-exposure to the same pathogen.

Signup and view all the flashcards

What do cytokines do?

Cytokines are chemical messengers that regulate the immune response, like a command system for immune cells.

Signup and view all the flashcards

How do cytotoxic T cells kill infected cells?

They directly kill infected cells by releasing enzymes that destroy the cell membrane or by inducing apoptosis (programmed cell death).

Signup and view all the flashcards

Role of B Cells in Adaptive Immunity

B cells differentiate into plasma cells that produce antibodies, which target and neutralize specific antigens.

Signup and view all the flashcards

How do antibodies contribute to immunity?

Antibodies can neutralize toxins, agglutinate pathogens, opsonize pathogens for phagocytosis, and block pathogen function.

Signup and view all the flashcards

What is the difference between T helper cells and cytotoxic T cells?

T helper cells activate other immune cells, while cytotoxic T cells directly kill infected cells. Think of the T helper cell as the commander and the cytotoxic T cell as the soldier.

Signup and view all the flashcards

What is inflammation?

The body's natural response to injury or infection, marked by redness, swelling, heat, and pain. It involves recruiting immune cells to fight off pathogens.

Signup and view all the flashcards

What are cytokines?

Signaling molecules released by immune cells that help coordinate the immune response by attracting other immune cells, activating them, and triggering inflammation.

Signup and view all the flashcards

What is the acute phase response?

The body's immediate response to inflammation, involving increased blood vessel permeability, mast cell activation, and cytokine release, leading to fever and lethargy.

Signup and view all the flashcards

What are opsonins?

Molecules that attach to pathogens, making it easier for phagocytes to recognize and engulf them.

Signup and view all the flashcards

What is CRP?

A type of opsonin that is produced in the liver during inflammation. Its levels can be measured to assess the severity of inflammation.

Signup and view all the flashcards

How does the innate immune system fight infections?

The innate immune system uses two main strategies: recruiting immune cells to the site of infection and engulfing and destroying pathogens through phagocytosis.

Signup and view all the flashcards

Study Notes

Cytotoxic T Cells

  • Cytotoxic T cells are responsible for killing infected cells
  • They bind to the infected cell via the T cell receptor binding to the MHC class 1 molecules expressing the relevant antigen
  • This binding triggers two mechanisms of cell destruction
    • Granule exocytosis: This is where the cytotoxic T cell sprays enzymes that destroy the infected cell's membrane. This leads to cell lysis and death
    • Fas molecule activation: The Fas molecule acts as a switch triggering apoptosis (programmed cell death) in the infected cell.

Plasma Cells & Antibodies

  • Plasma cells are B cells that have differentiated and become antibody-producing cells
  • Their role is to produce large amounts of antibodies specific to the invading pathogen
  • Antibodies are Y-shaped proteins
  • Antibodies have a variable region that matches different antigens
  • Antibodies are transported around the blood and bind to specific antigens
  • Functions of antibodies -Act as opsonins: Antibodies may sometimes be difficult for macrophages and neutrophils to recognise and engulf, but antibodies can act as opsonins to make it easier for phagocytosis to take place.
    • Agglutination: Antibodies can clump together pathogens after attaching to them, preventing the spread of the pathogen and making it easier for phagocytes to engulf them.
    • Neutralisation: Antibodies can attach to toxins and neutralise their effect by blocking their receptors
    • Attach to receptors of viruses and bacteria: Antibodies can prevent virus or bacteria function, e.g., stopping viruses from invading cells

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Description

Dive into the functions of cytotoxic T cells and plasma cells in the immune response. Learn how cytotoxic T cells kill infected cells and how plasma cells produce antibodies. This quiz explores critical mechanisms of immune defense and their implications in pathogenesis.

More Like This

Cytotoxic T cells
3 questions

Cytotoxic T cells

EnthralledDanburite avatar
EnthralledDanburite
Cytotoxic T Cells
5 questions

Cytotoxic T Cells

PhenomenalSmokyQuartz avatar
PhenomenalSmokyQuartz
Cytotoxic T Cells Quiz
5 questions

Cytotoxic T Cells Quiz

MarvellousPelican avatar
MarvellousPelican
Immunology Overview
28 questions

Immunology Overview

EthicalSine avatar
EthicalSine
Use Quizgecko on...
Browser
Open
Browser
Browser