Immune SystemAlex Wiemann

Immune System

The immune system defends the body against infection and disease-causing organisms.

Organs of the Immune SystemBone Marrow: where human immune

system cells are producedThymus Gland: produces more immune

system cells and lymphocytesSpleen: filters the blood using T-cells, B-

cells, macrophages, natural killer cells, and red blood cells

Lymph Nodes: filters the interstitial fluid between the cells

Recognizing Pathogens

Antibodies are proteins produced by B-cells that identify and neutralize pathogens.

The antibodies have receptors on them that connect to antigens, which are the part of the pathogens that allow antibodies to recognize them.

Innate and Acquired Immunity

Innate Immunity Acquired Immunity

Antigen-independent response Antigen-dependent response

Maximal response is immediate

Lag time between exposure and maximal response

Not antigen-specific Antigen-specific

No immunologic memory Immunologic memory

Skin, lysosomes, phagocytes, coughing, sneezing

Lymphocytes

Active and Passive Immunity

Active Immunity Passive Immunity

Host produces cells and factors responsible for immunity

Host acquires immune factors produced from another animal

Can work for a long time Usually lasts only for short time

The production of antibodies (due to disease or vaccination)

Injection of immune serum from an individual who previously had the disease

Humoral & Cell-Mediated Immunity

Humoral Immunity Cell-Mediated Immunity

Deals with infectious agents in the blood and body tissues

Deals with body cells that have been infected

Managed by B-cells Managed by T-cells

Uses antibodies Uses killer T-cells

B and T Lymphocytes

B-Cells T-Cells

Act against pathogens in the blood and lymph

Act against pathogens, organ transplants, cancer, etc.

Produce plasma cell clones, which produce antibodies

Produce T-cell clones, which can be killer, helper, or suppressor

Antibiotics Against Bacteria and Viruses

Antibiotics only work against bacteria, not viruses.

Antibiotics interrupt metabolic pathways in prokaryotic cells. This might prevent the formation of a cell wall or the completion of cell division.

Viruses have no metabolic pathways. For this reason, antibiotics do not work on them.

AllergiesAllergies are reactions your immune

system has to substances that most people don’t react to.

Symptoms include sneezing, breathing troubles, and vomiting.

One in every five Americans is affected by allergies.

There are several over-the-counter medications available to treat allergies.

HIV/AIDSHIV is the virus that causes AIDS. HIV/AIDS

weakens a person’s ability to fight cancer and disease and is transmitted sexually.

There usually are no immediate symptoms to HIV/AIDS, though some people do develop a flu-like illness.

0.6% of American adults have HIV/AIDS.HIV can be treated with certain

medications. There is no cure for AIDS.

Sources http://kidshealth.org/parent/general/body_basics/immu

ne.html http://pathmicro.med.sc.edu/ghaffar/innate.htm http://www.buzzle.com/articles/organs-of-the-immune-

system.html http://www.differencebetween.net/science/health/differ

ence-between-adaptive-and-innate-immunity/ http://en.wikipedia.org/wiki/Antibody http://www.textbookofbacteriology.net/immune.html http://library.thinkquest.org/C004367/be7.shtml http://www.circulatory-system.com/differences-betwee

n-b-cells-and-t-cells/

http://ibbiology.wetpaint.com/page/Explain+why+antibiotics+are+effective+against+bacteria+but+not+against+viruses

http://www.webmd.com/allergies/guide/allergies-treatment-care