Your Body’s Defense

Pathogens:  Bacteria- Some infections bacteria cause include sore throats (tonsillitis or strep throat), ear infections, cavities, and pneumonia  Viruses - Most viruses can't survive very long if they're not inside a living thing like a plant, animal, or person. Viruses cause chickenpox, measles, flu, and many other diseases!  Fungi - An example of something caused by fungi is athlete's foot, that itchy rash that teens and adults sometimes get between their toes.  Protozoa - Love moisture and often spread diseases through water. Some protozoa cause intestinal infections that lead to diarrhea & nausea.

Physical Defenses  First line of defense  Skin  Hair  Mucous  Cilia  Saliva  Tears  Sweat  Digestive tract

Skin  Protects from micro-organisms entering the body  Open cuts/ sores provide entrance  Cells die and are shed

Sweat  Our body has many sweat glands  Sweat is released to control body temp  Sweat contains acids that kill pathogens

Mucous Membranes  Moist linings around all entrances to body  Covered with mucous  Mucous = sticky substance  Mucous traps pathogens  Mucous is released from body

Saliva & Tears  Contain enzymes that fight pathogens  Tears wash away foreign substances

Cilia  Tiny hair-like structures  Trap pathogens  Help remove mucous from body

Digestive Tract  Moves pathogens out of body  Acids/ chemicals in digestive tract  Stomach/ intestines/ bladder  Chemicals kill pathogens

Second Line of Defense  Occurs after pathogen enters the body  Inflammation

Inflammation  1 st stage of healing  Increased blood flow to area  Increased size/ temperature/ redness  Caused by dilation of blood vessels

Phagocytes  Blood brings phagocytes & chemicals  Phagocytes = white blood cells Digest pathogens, dead cells, waste  Chemicals Kill pathogens & start tissue healing

Last line of defense- Immune System  Lymphatic system, lymph nodes, lymph, lymphocytes  Lymph nodes store and filter lymph  Lymph - fluid containing lymphocytes  Lymphocytes - white blood cells

Lymphocytes  B-cells & T-cells  T-cells Produce interferon- warns cells about pathogen Kill some pathogens directly  B-cells create antibodies Antibodies bind to pathogens/ toxins until phagocytes find them

Immunity  Active Immunity-body creates antibodies Through sickness or immunization  Immunization/ vaccine – injected with small amount of pathogen  Passive Immunity-passed from mother to child through birth or breast milk

Treatment  Antibiotics – kill living organisms Treat bacterial infections only  Fungi are treated with cream or topical treatment

Treatment of Virus  Anti-viral can stop a virus from reproducing Most viruses are fought by our immune system with… Rest Proper diet Water

Prevention  Eat well-balanced meals.  Get enough rest. (8 hours)  Get exercise. (30 minutes at least 3-4 x week)  Wash hands/ shower.  Keep hands out of eyes and mouth.  Have regular physicals/ dental visits.

Prevention  Get vaccinated  Don’t share utensils, glasses, cups etc.  Avoid sick people.  Avoid stress. Use stress management techniques.  Find time to relax.