Innate Immunity: First on the Scene
This branch of immunity is present before exposure to a pathogen and responds rapidly without requiring immunological memory.
What is innate immunity?
The general name for the white blood cells involved in immune defense.
What are leukocytes?
The process in which an immune cell engulfs a microorganism or other particle.
What is phagocytosis?
These molecules bind specifically to antigens and are produced by activated B cells/plasma cells.
What are antibodies?
A vaccine allows the immune system to “practice” recognizing a pathogen without requiring the person to first experience the disease. Which branch of immunity is being trained?
What is adaptive immunity?
Skin, mucous membranes, and antimicrobial substances are examples of this level of innate defense.
What is the first line of defense?
These granulocytes are particularly important during infections involving parasitic worms.
What are eosinophils?
During phagocytosis, the engulfed microorganism becomes enclosed inside this membrane-bound compartment.
What is a phagosome?
This antibody is typically produced first during a primary immune response.
What is IgM?
After an infection has been eliminated, most activated immune cells disappear but a smaller population remains behind for years. What is the purpose of these remaining cells?
What is immne memory/faster future response
Inflammation, fever, phagocytic cells, and complement are examples of this level of defense.
What is the second line of defense?
These short-lived phagocytes are often among the first immune cells to arrive at an infection site.
What are neutrophils?
After a phagosome forms, it fuses with this organelle containing digestive enzymes.
What is a lysosome?
This antibody is associated with longer-term immunity and can cross the placenta.
What is IgG?
Two people encounter the same pathogen. Person A has never encountered its antigens before. Person B encountered them several years ago.
Which person would generally begin producing a strong, specific immune response sooner?
Who is Person B?
An immune cell has receptors that recognize molecular features shared by many different bacteria rather than recognizing one specific bacterial strain. What type of receptor is allowing this recognition?
What is a pattern-recognition receptor (PRR)?
This long-lived phagocyte can engulf pathogens and release signals that influence other immune cells.
What is a macrophage?
A phagocyte successfully engulfs a bacterium, but a defect prevents the phagosome from fusing with lysosomes. What would be the most likely consequence?
What is the bacterium would be engulfed but would not be efficiently destroyed by lysosomal enzymes and other antimicrobial molecules?
A patient has very few functional CD4+ helper T cells. Which part of the adaptive immune response would likely become less effective because of this loss?
What is activation of other immune cells, especially B cells and their production of antibodies?
A researcher measures antibody levels following two separate exposures to the same antigen. After the second exposure, antibody levels rise much more rapidly.
What does this difference tell you about the immune system?
What is the immune system remembers previous exposure to an antigen?
A patient has normal neutrophils, but the cells cannot move toward chemical signals released from an infected tissue. Name the process that is defective.
What is chemotaxis?
An immune cell captures antigen in peripheral tissue, travels to a lymphoid organ, and activates a naive T cell. Identify the immune cell.
What is a dendritic cell?
Complement proteins coat the surface of a bacterium. A macrophage can now grab and engulf the bacterium much more efficiently. Name the complement function being demonstrated.
What is opsonization?
An antigen-presenting cell displays a piece of a pathogen to a T cell. Why is displaying the antigen important instead of simply destroying the pathogen and stopping there?
What is antigen presentation allows T cells to recognize the specific pathogen and helps activate a targeted adaptive immune response?
A vaccine does not create an immediate protective barrier around the body. Instead, its protection depends on something that happens after the vaccine antigen is recognized.
What must the adaptive immune system do for vaccination to provide future protection?
What is develop an antigen-specific response and establish immunological memory?