Immune System

• Innate Immunity - first and second line of defense
• 1st line of defense: skin and mucus
• skin - physical barrier
• mucus - traps debris and pathogens
• 2nd line of defense: inflammatory response
• inflammatory response (non-specific defense)
• Larger phagocytes/macrophages - eat pathogens and antigens outside of the cell for T-cell recognition
• fever - chemicals released to increase core body temperature
• 3rd line of defense - acquired immunity
• Acquired immunity response (specific defense)
• Specific defense requires lymphorytes
• Lymphorytes = T and B cells
• B-cells receive signal and create antibodies that bind to pathogens to mark destruction
• Killer T-cells bind to infected cells and kill/burst them
• Whole Blood = 55% plasma and 45% cells & platelets
• Plasma is made mostly of water
• Plasma transports nutrients, wastes, hormones, enzymes, and salts
• blood volume = amount of flluid in plasma
• Red blood cells are produced in bone marrow
• red blood cells have no nucleus and organalles
• red blood cells last for around 102 days until recycled in the liver and spleen
• red blood cells contain hemoglobin and surface proteins that determine blood type
• red blood cells job is to transport cells
• platelets - cell fragments produced in bone marrow
• platelets stick to wounds and release clotting factors
• hemophilia - deficiency in clotting factor
• white blood cells are produced from stem cells in the bone marrow
• white blood cells attack foreign substances
• some types of white blood cells must be mature (T-cells in the thymus or B-cells in bone marrow)
• When B and T cells are activated (Primary response), they also create long-lasting memory cells
• If memory cells encounter the antigen again, the memory cells will trigger a secondary response to eliminate the antigen much faster
• If you get a vaccine, you get a weakened or dead version of an antigen
• when the majority of people got a vaccine, people who haven't gotten it still are protected since the disease is less likely to spread
• herd immunity threshold - amount of people for herd immunity (usually 80-90%)