A PII Exam 3 Study Guide The Immune System Immune system Functional system made up of two intrinsic defense systems that act independently and cooperatively to provide resistance to disease o Lines of defense innate and adaptive systems are intertwined Proteins released during an innate response alerts cells of the adaptive system about the presence of a foreign substance o Innate and adaptive systems are intertwined proteins during an innate response alerts cells of the adaptive system about the presence of foreign substances Innate system nonspecific Recognizes and destroys foreign substances but the responses to them is the same each time because in innate immunity specificity and memory do not exist o 1st and 2nd lines of defense o 1st external membranes o 2nd takes effect when 1st has been penetrated It contains internal defenses o surface barriers skin resistant to weak acids bases toxins mucous membranes stomach secretes HCl and protein digesting enzymes to kill microorganisms saliva and lacrimal fluid contain lysozymes to destroy bacteria mucus traps microorganisms trying to enter openings o internal defenses phagocytes fever NK cells Antimicrobial proteins inflammation Adaptive system specific o 3rd line of defense o attacks foreign substances o takes longer than innate to work o Humoral immunity B cells o Cellular immunity T cells Surface barriers o Function skin mucous membranes and their secretions are the bodys first line of defense Keratin in the skin provides a tough barrier as the first line Mucous membranes provide the lining for all body cavities that open to the exterior Skin is keratinized epithelial membrane Nonspecific Cellular and Chemical Defense o 2nd line killing pathogens and repair tissue Second line of defense o Phagocytes 2 types confront pathogens Macrophages leaves the bloodstream in search of foreign substances Has a larger life span and can ingest more debris than neutrophils Neutrophils type of white blood cell that becomes phagocytic upon an encounter This is usually the first cell to leave the blood and enter infected tissue o Phagocytosis the process of phagocytes ingesting and destroying foreign substances Phagocyte adheres to a microbe and plasmic extensions bind to the particle and pull it inside a membrane lined vesicle Phagosome fuses with a lysosome to form a phagolysosome The microbe is then killed and digested by lyosomal enzymes leaving a residual body The residual material is removed from the phagocyte by exocytosis o Phagocyte mobilization Phagocytes flooding injured area after inflammation by 4 steps 1 Leukocytosis neutrophils enter blood from bone marrow 2 Margination neutrophils cling to capillary wall 3 Diapedesis neutrophils flatten and squeeze out of capillaries 4 Chemotaxis neutrophils follow chemical trail o Other factors Response o Injury Release of chemical mediators such as cytokines promote inflammation and attract WBCs histamine kinins prostaglandins leukotrienes and complement will induce vasodilation of small blood vessels in the injured area Chemicals also increase permeability of capillaries exudates accumulate which causes swelling pressure on nerves causes pain o Reactive hyperemia the opposite of hyperemia Instead of vasodilation vasoconstriction occurs limiting blood flow An example is Raynaud s Phenomenon More blood flow hyperemia accounts for redness and heat o Mechanisms of occlusion training Results in reactive hyperemia mediated vasodilation closing of a blood vessel Fiber type recruitment accumulation of metabolites lactate GH mTOR activation protein synthesis pathway o Inflammatory response is triggered when body tissues are injured To prevent the spread of damaging agents to nearby tissues disposes of cell debris and pathogens and sets the stage for repair Antimicrobial Proteins enhance the innate defenses by attacking microorganisms not allowing reproduction o Interferons secreted by virus infected cells Stimulate production of proteins that will interfere with viral replication in healthy cells IFN alpha used to treat genital warts hepatitis C IFN Beta used to treat MS IFN Gamma used to treat granulomatous disease abnormal WBCs o Complement inactive proteins in blood Cascade of activation of proteins This activation releases chemicals which amplify inflammation through vasodilatory release causing cell lysis apoptosis Biochemical pathways o Classical pathway part of the adaptive immunity because it is involved with the binding of antibodies to the invading pathogen Gets initiated when antibodies bind to antigens of a pathogen o Alternative pathway part of the innate immunity and is spontaneously activated It begins after the classical pathway when C3 becomes activated and is split Adaptive defense system also called specific recognizes and destroys foreign objects but the response to them gets faster and stronger each time because it has specificity and memory o cells engulf and digest antigens that it encounters and present fragments of the antigen on their own surfaces to be recognized by T cells o Acquired through a persons lifetime o Contains 3rd line of defense B cells and T cells o Can be broken down into two types Humoral and Cellular o Humoral involves proteins antibodies B cells are responsible for humoral immunity Antibodies bind to bacteria and their toxins and free viruses o Cellular involves T cells Lymphocytes attack virus or parasite infected cells o Response are elicited by ANTIGENS Antigens large complex molecules stimulate an adaptive immune response complete and incomplete Complete immunogenicity and reactivity Antigenic Determinants specific parts of an antigen that is Incomplete reactivity ex Haptens immunogenic where antibodies attach themselves Self Antigens MHC proteins a group of proteins that are coded for by genes and are unique to each individual except for twins divided into Class I and Class II Class I is gound on virtually all body cells class II is found on certain cells in the immune response Fever elevated body temperature a systemic response to invading microorganisms Body temp is regulated by neurons in hypothalamus The Integumentary System Skin Characteristics Layers of the epidermis epithelial cells o Surface area 1 2 2 2 sq meters o Weight 4 5 kg o 7 of total body weight o Hypodermis subcutaneous tissue deep to the skin also called superficial fascia and is mostly adipose tissue o Color is determined by melanin carotene and hemoglobin o Melanin is made of
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