Body defends itself from any sort of threat not belonging the body.

Any threat = Antigen

Anything that causes diseases = Pathogen

Bacteria: capable of living on its own.

Virus: tiny and has DNA; must hijack other cells for energy. 

Protozoans: larger eukaryotic organisms

Fungi: molds & yeast

Worms: Parasitic on humans

Prions: protein that causes infections

Granulocytes & Agranulocytes

Maintains blood volume

Transports products of fat digestion from small intestine to blood stream

Defends against disease-causing organisms

Spleen:

Destroys red blood cells

Produces Lymphocytes

Lymph Nodes:

Contains Lymphocytes & Macrophages

Filters lymphs and removes foreign bodies

Physical & Chemical Barriers

Non-specific Defense

Specific defense

Physical: skin and mucous membrane.

Chemical: oil, tear, sweat, HCl in stomach, acidity in urine, enzymes

Reacts to anything that breaks through the first line of defense

Defensive proteins (2) - interferon and complement system

Inflammation - swell

Fever- hot temperature allows blood to flow faster

interferon - interferes viruses & slows viral reproduction. attracts macrophages & protects surrounding cells

complement system - helps out the rest of the immune system directly destroys, inflammation and attracts macrophages and WBC's

destroys invaders & repairs damaged tissue.

redness, heat, swelling and pain!

aka Immnue Response

Specific & Remembers

Threat

Detection

Alert

Builds Specific Defense

Defense

Continues surveillance

Withdrawal of forces

Immune Response (Steps 1 & 2)

Threat - Foreign cell or molecule enters the body

Detection - Macrophages engulfs foreign cells.

Alert - Macrophages engulfs material; breaks it into smaller pieces and some moved to plasma membrane

Alarm - T helper cells help activate both specific & non-specific defense

Build Specific Defenses:

Tcells and Bcells go into duty

Once active both T cells and B cells multiply

Cells produced designed to kill ONLY  that specific antigen

Antibody-mediated defense: B-cells clump antigen together

Cell-mediated defense: T-cells cause antigen to burst.

Immune Response (Step 7)

Continued Surveillance:

Memory cells formed once T-cells and B-cells are activated. Continously patrols for antigen.

Withdrawal of forces:

when immune system begins to conquer invader.

Supressor T-cells release chemicals and shut down B-cells & T-cells

turns off immunte system when antigen is no longer a threat

When antigen first enters the body:

Needs time to produce antibodies to fight off antigen

No lapse since antibodies are already formed (thanks to memory!)

exposure to innert or weakened antigen therefore triggering the immune system to produce antibodies

involnurable due to secondary response

When body begins attacking itself

organ-specific - occurs within one specific organ

non-specific-organ - occurs throughout the body