immunity adapted from adlai e. stevenson high school
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Immunity
Adapted from Adlai E. Stevenson High School
Primary Function of the Immune System
Provides protection against disruption by pathogens or toxins
Helps discriminate between “self” and “nonself” Pathogen - Definition:
– Any disease causing agent (microorganisms) Types:
– Bacteria– Viruses– Parasites– Fungi
The DefensesNon-Specific
Definition:– Agents do not have to recognize a foreign
invader to fight it (work by preventing pathogen from entering the body)
Examples:– Skin– Tears– Saliva– Sweat – Mucus– Macrophage
The DefensesSpecific Definition:
– Agents attacks only certain invaders, specialized defense
Types of Cells– Helper T cells
• 1st line of specific defense• Help recruit other immune cells & tell them to
attack certain invaders
– Killer T cells• Can distinguish virus infected cells from
uninfected cells by the unique molecular signals on the infected cells surface
– B cells• Told by helper T cells to make antibodies to
prevent specific antigens from hurting the body…. “Memory”
Lymphocyte Function
T cell response– Attach to foreign
antigen bearing cells and interact directly
Cell Mediated Immunity
Humoral
Immunity B cell response
– Differentiate into plasma cells
– Produce antibodies
Antibodies & Antigens Proteins Can recognize
chemical signals from another cell (pathogen)
“Self” Y shape
Chemical signal on the surface of a pathogen
Cell Mediated Immunity
Cytotoxic T cells
Killer T cells recognize body cells infected with a virus; then destroy those cells by drilling holes in their plasma membranes.
Cell or Antibody Mediated Immunity
Helper T cells
Helper T cells start the immune response by activating B or T cells.
Macrophage Antigen-presenting cell
Helper T cell
Antigen-presenting cell APCB cell
suppressorT cell
cytotoxicT cell
T cells and cell-mediated immunity
Antibody Mediated Immunity
B cells– Activated when it
encounters an antigen that fits its antigen receptor
– Proliferates (colonial expansion)
• Plasma cells-->antibodies
• Memory cells-->future fights
Vaccines What is in the shot they give you?
– Dead or inactive (attenuated) pathogens How does it work?
– Cause B cells to make antibodies against the foreign antigen
The Memory of Infection
Autoimmune Disorders “Auto” = self Definition: a disease in
which the immune system attacks the tissue of the body; cause is generally unknown
Immune system distinguishes “self” from “non-self
Examples: – multiple sclerosis (MS) - T
cells destroy myelin sheath around neurons
Cold Virus, Rubella, & Strep Common Cold Virus
– Influenza; contagious viral infection of the nose, throat and lungs which often occurs in the winter.
Rubella virus– German measles
Streptococcus bacterium– Strep throat is an
infection of the pharynx caused by streptococcus bacteria.
Treatments:– Strep Throat
• Antibiotics such as penicillin or erythromycin
– Rubella• Vaccine
– Influenza
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