MIC 205 1st Edition Lecture 20Outline of Last LectureI. Administration of Antimicrobial DrugsII. Side effectsIII. Development of resistant organismsIV. Defense mechanismsOutline of Current Lecture V. Nonspecific defensesa. Second line i. Phagocytosisii. Inflammationiii. Feveriv. Nonspecific chemical defensesv.Current Lecture Nonspecific- Second Line Defenses:- Bloodo Fluid components (plasma) Mostly water, contains electrolytes, nutrients, proteins- Fluid without clotting factors = serumo Cellular components (formed elements)- Hematopoiesis= how formed elements come to be Erythrocytes- red blood cells carry oxygen and CO2 Platelets- cell fragments for blood clotting Leukocytes- white blood cells, defend the body against invaders- Macrophageso Phagocytic cells in the second line of defense Wandering macrophages leave the blood and eat up foreign invaders- Leave blood by process called diapedesis Fixed macrophages stay in home tissue (resident)o CBC (complete blood count)- differential white blood cell count can signal signs of disease Viral infection = increase in lymphocytes Bacterial disease = increase in white blood cellsThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Phagocytosiso Phagocytes (leukocytes or derivatives of them) 5 stages1. Chemotaxis2. Adherence3. Indigestion4. Digestion5. Elimination- Phagocytosis Blocking Mechanisms:o Chemotaxis: chemical attractants o Adherence: attach phagocyte to microbe with cellular receptorso Indigestion: phagosome (vacuole)o Digestion: phagosome fusion to lysosomeo Elimination:Phagocytosis- Protection to self:- Body cells are marked with autoantigens that project them from phagocytosisInflammation-Second line defense mechanism (Know general steps of inflammation)- Nonspecific response caused by TISSUE DAMAGEo Signs: Redness, heat, swelling, pain- Acute inflammation: o Develops quick, short lived, beneficial Dilate and increase permeability of blood vessels Migration of phagocytes Tissue repair- Chronic inflammation:o Develops slowly and lasts longo Can cause tissue damageFever-2nd line defense: (Know general steps of fever production)- Body temp over 98.6 degrees F (37 C)- Chemicals called pyrogens trigger the hypothalamus to increase body core tempNonspecific Chemical Defenses-2nd line:- Chemical responses provide protection against broad classes of foreign invaders (viruses, bacteria, fungi)o Complement System** (cellular pathogens)o Interferon System** (viral pathogens)- Complement Systemo Set of serum proteins activated by cellular invaders Promotes inflammation Stimulate phagocytosis Formation of membrane attack complex for lysis of a cellular invader- Interferon Systemo Group of proteins released by virus infected cells to nonspecifically inhibit the spread of viral infections Interferons signal neighboring cells to produce antiviral proteins (AVP) AVPs block viral replication to slow infectiono Interferon can cause signs and symptoms of viral infectionso (DON’T NEED TO KNOW
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