b and t cell response

b cell response

B cells respond to pathogens and other cells from outside the body in the blood and lymph. Most B cells fight infections by making antibodies. An antibody is a large, Y-shaped protein that binds to an antigen, a protein that is recognized as foreign. Antigens are found on the outside of bacteria, viruses and other foreign microorganisms. Each antibody can bind with just one specific type of antigen ( Figure 1.1). They fit together like a lock and key. Once an antigen and antibody bind together, they signal for a phagocyte to destroy them. Phagocytes are white blood cells that engulf targeted antigens by phagocytosis. As the antigen is on the outside of a pathogen, the pathogen is destroyed by this process. At any one time the average human body contains antibodies that can react with about 100,000,000 different antigens. This means that there can be 100,000,000 different antibody proteins in the body.


b and t cell response

Some defenses, like your skin and mucous membranes, are not designed to ward off a specific pathogen. They are just general defenders against disease. Your body also has defenses that are more specialized. Through the help of your immune system, your body can generate an army of cells to kill that one specific pathogen. There are two different types of specific immune responses. One type involves B cells. The other type involves T cells. Recall that B cells and T cells are types of white blood cells that are key in the immune response. Whereas the immune systems first and second line of defense are more generalized or non-specific, the immune response is specific. It can be described as a specific response to a specific pathogen, meaning it uses methods to target just one pathogen at a time. These methods involve B and T cells.

t cell response

There are different types of T cells, including killer T cells and helper T cells. Killer T cells destroy infected, damaged, or cancerous body cells ( Figure 1.2). When the killer T cell comes into contact with the infected cell, it releases poisons. The poisons make tiny holes in the cell membrane of the infected cell. This causes the cell to burst open. Both the infected cell and the pathogens inside it are destroyed. Helper T cells do not destroy infected or damaged body cells. But they are still necessary for an immune response. They help by releasing chemicals that control other lymphocytes. The chemicals released by helper T cells switch on both B cells and killer T cells so they can recognize and fight specific pathogens.


instructional diagrams

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the human body can detect well over 1,000,000 different antigens.

-->  a. true

b. false

pathogens are destroyed by antibodies.

a. true

-->  b. false

how do killer t cells do their job?

a) they engulf targeted cells so they can be destroyed.

-->  b) they release poisons that cause targeted cells to burst.

c) they make antibodies that bond to cells with antigens.

d) all of the above

how do helper t cells do their job?

a) they help to make antibodies.

b) they help by poisoning infected cells.

-->  c) they release chemicals that activate other t cells and b cells.

d) they help by marking infected cells for destruction.

which cell will fight cancerous cells?

a) b cell

b) helper t cell

-->  c) killer t cell

d) killer b cell

what signals a pathogen for destruction during the immune response?

-->  a) the binding of an antibody to its antigen.

b) the antigen on the surface of a pathogen.

c) the antibody on the surface of a pathogen.

d) the binding of an antigen to a pathogen.

what statement best describes the immune response?

a) the immune response fights pathogens by producing antigens.

b) the immune response fights pathogens with b and t cells.

c) the immune response is a general response to a specific pathogen.

-->  d) the immune response is a specific response to a specific pathogen.

diagram questions

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