Immune System

Fights Germs and Infections Carries white blood cells & filters out harmful bacteria and viruses Removes Waste and Toxins Collects waste from body tissues & moves it to the bloodstream for removal Maintains Fluid Balance Collects extra fluid (lymph) from tissues & returns it to the bloodstream Transports Fats Absorbs fats and vitamins from the small intestine & moves them into the bloodstream

The purpose of the immune system is to provide protection against disease-causing agents.

Filter lymph before it is returned to the blood near the heart and aids the body’s Immune System White Blood Cells (WBC’s) cells in nodes:

Several other organs contribute to lymphatic function Spleen Thymus Tonsils Peyer’s patches

Pathogens = disease-producing agents. Not all microorganisms are pathogenic. Microorganisms live on skin, in the intestines, upper respiratory tract, lower urinary tract, reproductive tract, etc… Some have symbiotic relationships with our bodies, help maintain homeostasis.

Passive Immunity - immune defenses transferred from mothers to babies, or from monoclonal antibody therapy

Active Immunity - when your body makes its own antibodies against a specific pathogen because of exposure or vaccination.

Vaccines–small amounts of weakened or dead pathogens that stimulate an immune response to develop active immunity.

1st Line- ( Non specific ) In order for pathogens to enter… they must first break through your skin. They will first encounter the body’s secretions (sweat, oil, mucus, tears, saliva) Main function of mucus is to prevent areas from drying out. It also traps microorganisms. 2nd Line - ( Non specific ) White blood cells, are responsible for protecting your body from infection. They circulate in your blood and respond to injury or illness. In the 2nd line of defense, the WBCs respond in a non-specific way, attacking ANY invaders that break in the body’s outer barriers. 3rd Line- ( Specific )- Specific white blood cells can locate the site of an infection and notify other white blood cells of their location. They fight the invader by producing specific antibody proteins to attach to the organism and destroy it.

Macrophages - ingest and break down foreign materials. T-Cells - recognize antigens* and reproduce rapidly. Some attack foreign material and some signal for B cells.