Immune System

How do pathogens get into the body? Openings NOSE MOUTH EYE CUTS AND PUNCTURES Pathogens are disease-producing agents, such as bacteria and viruses.

Immune System Disease can be transmitted to humans in various ways: Common inanimate objects Insects Airborne droplets or dust particles

Touch And of course… Immune System

Viruses Bacteria Vaccines Antibiotics Immune System What causes disease? Treatment for disease?

Skin is your first line of defense. Body secretions (mucus, oil, sweat, tears, and saliva) provide protection from pathogens. Immunity

If a pathogen gets passed your skin, the next step is inflammation of the tissues. –Redness, Swelling, Pain, and Heat are all part of the immune response to rid your body of harmful agents. –White blood cells rush to the scene of the accident to prevent the spread of the pathogen. Immunity You can own your own Red Blood Cell & White Blood Cell…. Call now! Supplies are limited!

Pus is a collection of living and dead white blood cells, and pathogens. The pus will continue to form until the infection has ended. Once over, the pus will be cleared away by macrophages (a type of white blood cell). Immunity

Immune System The organs, glands, and cells of the immune system provide protection through a network called the lymphatic system. They house the leukocytes, white blood cells.

Types of Leukocytes: Phagocytes: cells that engulf (take in), destroy, and digest invading organisms. Lymphocytes are cells that allow the body to remember and recognize previous invaders. When pathogens invade, leukocytes begin defending right away

Lymphocytes B lymphocytes or B cells – seek out pathogens and send antibodies (markers) to lock onto them T lymphocytes or T cells – T cells are like the soldiers, destroying the marked invaders.

White Blood Cells (WBC): –Large –several different types –all contain nuclei –defend the body against disease –transported by veins/arteries White Blood Cells

WBCs are created in the bone marrow –f–found in your: Humerus Femur Sternum Ribs Vertebrae Pelvis

Think of bone marrow as the cream filling of a Twinkie! White Blood Cells

Parts of the Lymphatic System: Lymph nodes Tonsils Thymus Spleen Appendix Adenoids Lymph Vessels Lymph Fluid Lymphocytes Immunity

Glands and Organs Lymph nodes: small masses of tissue that store lymphocytes and filter pathogens from the body. Where are they found in your body??? Lymph nodes swell when you have a viral or bacterial infection

Glands and Organs The spleen stores some lymphocytes, and filters and destroys bacteria and worn out red blood cells….in other words it cleans the blood.

Glands and Organs The Thymus gland stores lymphocytes until they mature and then are released to defend the body. Also creates and releases a hormone that stimulates the production of white blood cells in the bone marrow.

Immune System QUIZ

1. What is a pathogen?

2. How do pathogens enter the body?

3. What type of cell engulfs pathogens?

4. What system is responsible for immunity?

5. What is the difference between a B cell & a T cell?