Immune System Test AP Bio

Innate immunity

The body's first line of defense against pathogens, using non-specific barriers and cells for example skin and phagocytes

Acquired immunity

Specific immunity developed after exposure to a pathogen, involving B cells, T cells, and memory cells.

Lysozyme

An enzyme that breaks down bacterial cell walls, found in tears, saliva, and mucus

Neutrophil

A type of white blood cell that engulfs and destroys pathogens during an infection.

Macrophage

A large white blood cell that engulfs pathogens and dead cells and can present antigens to T cells.

Interferons

Cytokine that helps fight viruses

Complements System

Protein cascade enhancing immunity

Inflammatory response

A defense mechanism involving redness, swelling, heat, and pain to bring immune cells to an infection site.

Mast cells

Release histamine during allergic reactions

Histamine

Triggers inflammation and increases blood flow

Pyrogens

Substances that cause fever by raising the body's temperature.

Natural killer cells

Kills infected or abnormal cells

Lymphocytes

White blood cells, including B and T cells, involved in adaptive immunity

T cells

Lymphocytes that mature in the thymus and help kill infected cells or activate other immune cells.

B cells

Lymphocytes that mature in the bone marrow and produce antibodies.

Antigen

A molecule or part of a pathogen that triggers an immune response.

Antigen receptors

Proteins on B and T cells that specifically recognize and bind to antigens.

Antibody/ immunoglobulin

Protein that binds to antigens

Class I MHC

Proteins on all nucleated cells that display antigens to Cytotoxic T cells

Helper T cells

Activates B and cytotoxic T cells

Effector cells

Act immediately (plasma cells produce antibodies)

Memory cells

Provide long-term immunity by recognizing antigens upon re-exposure

Clonal selection

The process where specific B or T cells are activated and multiplied in response to an antigen

Primary immune response

The body's initial response to an antigen, slower because it's the first exposure

Plasma cells

Activated B cells that produce antibodies.

secondary response

and stronger immune response during re-exposure to an antigen, thanks to memory cells

Humoral immune response

B cell-mediated; involves antibodies

Cell mediated response

T cell-mediated; targets infected cells

CD4

A surface protein on Helper T cells that helps them bind to MHC class II molecules

CD8

A surface protein on Cytotoxic T cells that helps them bind to MHC class I molecules

Active immunity

Immunity developed through exposure to an antigen for example infection or vaccination

Passive immunity

Temporary immunity from receiving antibodies for example from mother to baby or through antibody injections

AIDS

A disease caused by HIV, which destroys Helper T cells and weakens the immune system

Allergens

Substances that trigger allergic reactions for example pollen or dust

Autoimmune disease

where the immune system attacks the body's own cells for example lupus or type 1 diabetes

What are the components of the innate immune system? And what is the function of each?

• Skin and mucous membranes: Physical barriers to pathogens.

• Phagocytic cells (e.g., macrophages, neutrophils): Engulf and destroy pathogens.

• Natural Killer (NK) cells: Kill infected or cancerous cells.

• Dendritic cells: Present antigens to adaptive immune cells.

• Complement system: Proteins that enhance pathogen destruction.

• Cytokines: Signaling molecules that regulate immune responses.

• Inflammatory response: Mobilizes immune cells to sites of injury or infection.

What is the order of events for an inflammatory response

• Tissue injury causes release of histamines and cytokines.

• Blood vessels dilate, increasing permeability.

• Phagocytes migrate to the site (chemotaxis).

• Pathogens are engulfed, and debris is cleared.

What are the components of the adaptive immune response

• B cells: Produce antibodies.

• T cells: Includes Helper T (CD4+) and Cytotoxic T (CD8+) cells.

• Antibodies: Bind specifically to antigens.

• Antigen-presenting cells (APCs): Present antigens to activate T cells.

What is the order of events that initiates an adaptive immune response

•Pathogen is engulfed by an APC.

•APC presents antigen on its MHC molecule to a Helper T cell.

•Helper T cell activates B cells and Cytotoxic T cells.

•B cells produce antibodies; Cytotoxic T cells destroy infected cells.

Which immune response happens in response to a SPECIFIC invader

Adaptive immune response

HIV infects which type of immune cell

Helper T cells (CD4+ cells)

Which special surface protein is found on Helper T that helps it interact with the MHC

CD4, which interacts with MHC class II

Which special surface protein is found of Cytotoxic T that helps it interact with the MHC

CD8, which interacts with MHC class I.

Differentiate between class I and class II MHC

• Class I MHC: Found on all nucleated cells; presents antigens to Cytotoxic T cells.

• Class II MHC: Found on APCs; presents antigens to Helper T cells.

What are two examples of active immunity

Vaccination, recovery from an infection.

What are two examples of passive immunity

Maternal antibodies through placenta or breast milk, antibody injections like for snake venom

How are these terms related: B lymphocytes and plasma cells

B lymphocytes change into plasma cells, which produce antibodies.

Which type of antigens does each red blood cell have for each blood type

• Type A: A antigens.

• Type B: B antigens.

• Type AB: A and B antigens.

• Type O: No antigens.

Which type of antibodies does each blood type have circulating in the blood plasma

• Type A: Anti-B.

• Type B: Anti-A.

• Type AB: None.

• Type O: Anti-A and Anti-B.

Which type of antigen does the Rh(+) and RH(-) person have

• Rh (+): Rh antigen present.

• Rh (-): No Rh antigen.

Describe what happens when a generic phagocyte engulfs a cell

The phagocyte engulfs the pathogen into a vesicle (phagosome), fuses it with a lysosome, digests the pathogen, and expels debris.

Describe what happens when B lymphocytes get activated

B cells bind to antigens, receive signals from Helper T cells, and differentiate into plasma cells (antibody producers) and memory B cells.

What cell type activates BOTH the humoral and cell mediated response

Helper T cells (CD4+)

Why are B cells and T cells called by each letter

• B cells: Mature in the bone marrow.

• T cells: Mature in the thymus.

What does cytotoxic T cell antigen bind to? Yes antigens but where are they displayed?

Bind to antigens presented on Class I MHC molecules on infected cells.

Make sure you KNOW the diagrams on the slideshow

;)