Chemical and Biological Injury

Chemical Injury Poison to the cell It is the dose that makes something poisonous Affects permeability of the cell membrane Tylenol can by poisonous in high concentrations, lead is poisonous is small amounts

Chemical Injury Vitamins Vitamin C you can take as much as you want (as is B) It is water soluble and passes through you Vitamin E fat soluble and can be toxic to the liver (as can A,D,E,K) Carcinogens Chemicals that lead to cancer (CA)

Biological Injury Parasites world-wide problem malaria are not common in the USA person probably out of the country

Biological Injury

Biological Injury Bacteria: tiny, primitive cell lacking a nucleus too large to get inside of our cells they usually cause disease through a release of toxins take in glucose and release toxins which make you sick

Biological Injury What defenses do you have against bacteria? Mucus Protects every cell Conditions for optimal bacterial growth Heat 98.6*F Ideal for binary fission reproduction Moisture Food

Defense Strategies Besides mucus cells, our bodies have another defense mechanism Immune response First Line of Defense Against Bacteria Neutrophils Most common type of white blood cells Circulate in blood then move to tissue Attack and consume bacteria through phagocytosis Contain numerous lysosomes filled with digestive enzymes

Defense Strategies Provide chemical signals called CYTOKINES carry messages between the cells of the immune system Circulate in blood then move to tissue “Watch dogs” of your immune system Main constituent of pus

Defense Strategies

Defense Strategies 2nd Line of Defense Monocytes Another type of white blood cell Slower moving but much more lethal By the time monocytes arrive, most of the bacteria is already dead They would be the battleships of the military analogy

Defense Strategies If monocyte level is elevated on a blood test, the infection has been going on for a while Often elevated in chronic bacterial infections (most bacterial infections are acute)

Both neutrophils and monocytes are produced in the bone marrow Most effective production occurs when you are sleeping Why? You are using the least amount of energy which can then be used to produce wbc What is a common problem when students go to university?

Other Defenses Lymphocytes T-cells attack cells that contain viruses B-cells produce antibodies against antigens Eosinphils release enzymes for fighting parasites destroy allergens

Other Defenses Basophils Least common Prevent blood from clotting too quickly Contains vasodilator histamine Increases blood flow to the tissues

Inflammation Most common and visible response to injury Serves to destroy or remove bacteria and diseased tissue Inflammation of tissue or organ is designated by the suffix itis

Inflammation 2 stages vascular arterioles constrict and then dilate movement of plasma into the interstitial space causes edema (swelling) cellular release of histamine increases capillary permeability

Inflammation Signs Redness arterioles dilate circulation to the site increases Heat results from local vasodilation fluid leakage into interstitial spaces increased blood flow

Inflammation Pain pain receptors are stimulated by swollen tissue Edema (swelling) local vasodilation fluid leakage Loss of function occurs as a result of edema and pain

Kinins proteins in blood that increase blood flow make it easier for fluids to pass through small capillaries stimulate pain receptors activate white blood cells