Your Body’s Defense

Your Body’s Defense

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

Mouth/Esophagus/ Stomach/ intestines

Chemicals kill pathogens

Second Line of Defense

Occurs after pathogen enters the body Inflammation

Inflammation 1st 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

Immune System Last line of defense 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 of

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

Fungus 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.

Questions