31.3 Immune Responses

Bell Ringer: Review! What is one of the bodies nonspecific defenses against an invading pathogen?

A)AntibodiesB)Killer T CellsC)Mucous, sweat and tearsD)Antibiotics

31.3 Immune Responses

KEY CONCEPTThe immune system has many responses to pathogens and foreign cells.

31.3 Immune Responses

• The job of the immune systems is to fight off pathogens & infections.

– Skin is a physical barrier to infection.– Mucous Membranes trap pathogens entering

the body.

31.3 Immune Responses

Two nonspecific responses.

1. Inflammation - blood vessels become leaky.• characterized by swelling,

redness, and pain

2. Fever - body temperature increases • Low fevers stimulate white

blood cells to mature.

31.3 Immune Responses

Cells of the immune system produce SPECIFIC RESPONSES

• Specific Immune response: –Antigens are surface

proteins on pathogens.–Each pathogen has a

different antigen.

antigens

31.3 Immune Responses

White Blood Cells attack infections inside the body.1.Phagocytes engulf and destroy pathogens.

2.T cells destroy infected cells.

3.B cells produce antibodies.- Antibodies make

pathogens ineffective.

31.3 Immune Responses

pathogen

antigens

T cell

receptors activated T cells

antigens

memory T cells

There are 2 specific immune responses.

1. Cellular Immunity T-cells to destroy infected body cells.

31.3 Immune Responses

31.3 Immune Responses

2. Antibody (humoral) Immunity B-cells produce antibodies.

memory B cells

activated B cells

antibodies

B cell

T cell

pathogen

31.3 Immune ResponsesBoth responses produce memory cells

31.3 Immune Responses

• Vaccines –Allow person to acquire immunity without

contracting disease–Contain the antigen of a weakened

pathogen–Does not cure a person who is sick

31.3 Immune Responses

– stimulates a specific immune response

– causes memory B & T cells to be produced

– allows immune system to respond quickly to infection next time

– has such a fast response, a person will not get sick

A memory B cell isstimulated when the real pathogen binds to it.

2

The B cell quickly activates and makes antibodies that fight the pathogens before you get sick.

3

Antigens in a vaccinetrigger an immune response, and memory B cells are made.

1memory B cells

• Vaccination provides immunity.

31.3 Immune Responses

To Do:

• Go to: http://www.biomanbio.com/GamesandLabs/Physiogames/conflictimmunity.html

• Play through the game, think about the steps required for the establishment of immunity

• In groups of 2-3, make a short powerpoint presentation walking through the steps of acquiring cell mediated or humoral immunity

• Once done, one group from each will present in front of class

31.3 Immune Responses

Bell Closer:

• What is the role of the macrophage?

A) Produces antibodies

B) Engulfs pathogens

C) Produces long lasting memory cells

D) Protects against pathogen entry