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Conspectus Of Disease


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Conspectus Of Disease

  1. 1. Chapter 1. conspectus of disease Yu-Hong Jia, Ph.D Department of pathophysiology Dalian medical university
  2. 2. <ul><li>concept of disease </li></ul><ul><li>etiology of diseas </li></ul><ul><li>pathogenesis of disease </li></ul><ul><li>outcome of disease. </li></ul>
  3. 3. 1. Concept of disease <ul><li>Disease: is referred as aberrant manifestation of deregulated homeostasis caused by harmful agents in a certain condition. </li></ul><ul><li>A certain condition </li></ul><ul><li>Cause of disease </li></ul><ul><li>The interation of damage and anti-damage </li></ul><ul><li>A series of funtional, metabolic and structural alterations in the body </li></ul><ul><li>Clinical Signs and symptoms </li></ul>Cold, low resistance Flu virus Increased immunoresponse Changes of Glucose, fat and protein metabolism Alteration of cardiopulmonary function Catarrh(nose running,sneeze,)Cough, fever, Flu
  4. 4. Health <ul><li>Former definition of health: </li></ul><ul><li>The state of the organism when it functions </li></ul><ul><li>optimally without any evidence of disease. </li></ul><ul><li>Definition of health from WHO: </li></ul><ul><li>Health indicates not only without any evidence </li></ul><ul><li>of disease, but also a state of complete well- </li></ul><ul><li>being physically, psychologically and socially. </li></ul>
  5. 5. Sub-health <ul><li>A situation in which the person does not show specific symptoms and signs of illness, but lives a low-quality of life both physically and mentally. </li></ul>
  6. 6. 2. Etiology of disease. Contributing factors that cause disease. Causative factors Predisposing factors Precipitating factors
  7. 7. <ul><li>Extrinsic factors </li></ul><ul><li>Intrinsic factors </li></ul>(1) Causes of disease (causative factors)
  8. 8. <ul><ul><li>Biological agents: microorganisms and parasites </li></ul></ul><ul><ul><li>Chemical agents: non-specific or specific </li></ul></ul><ul><ul><li>Physical agents: mechanical injuries, extremes of temperature, electricity and radiation. Participate in initiation but not development of disease. Non-specific injury. </li></ul></ul><ul><ul><li>Nutritional imbalance: excesses or deficiencies of nutrients. </li></ul></ul><ul><li>Extrinsic causes </li></ul>
  9. 9. <ul><li>Intrinsic factors </li></ul><ul><ul><li>Genetic factors: single or polygenic mutation </li></ul></ul><ul><ul><li>Congenital factors: abnormal embryonic developmental error </li></ul></ul><ul><ul><li>Immunological factors: the immune response is deficient or inappropriately strong or misdirected </li></ul></ul><ul><ul><li>Psychological factors: Anxiety, strong or persistent </li></ul></ul><ul><ul><li>psychological stress. </li></ul></ul>
  10. 10. (2) Predisposing factor <ul><li>influence the susceptibility or resistance to certain disease. </li></ul><ul><ul><li>Genetic constitution </li></ul></ul><ul><ul><li>Physiological diathesis </li></ul></ul><ul><ul><li>Psychological characteristics </li></ul></ul>
  11. 11. (3) Precipitating factor <ul><li>intensify the roles of causative factors and promote the onset and development of diseases. </li></ul><ul><ul><li>Natural condition e.g. weather condition, geographical environment </li></ul></ul><ul><ul><li>Physical condition e.g. physical or mental fatigue or anxiety </li></ul></ul><ul><ul><li>Social condition e.g. poor labor and hygiene condition </li></ul></ul>
  12. 12. <ul><li>Pathogenesis of disease refers to the rules and mechanisms underlying the development or evolution of the disease. </li></ul><ul><ul><li>General rules for pathogenesis of disease </li></ul></ul><ul><ul><li>Fundamental mechanisms for disease </li></ul></ul>3. Pathogenesis of disease
  13. 13. (1) General rule for pathogenesis of disease <ul><li>Disruption of homeostasis </li></ul><ul><li>Process of damage and anti-damage </li></ul><ul><li>Reversal rule of cause and result </li></ul><ul><li>Correlation between systemic and local regulations </li></ul>? ? ? ?
  14. 14. 1) Disruption of homeostasis <ul><li>Homeostasis denotes the process whereby the internal environment of an organism tends to remain balanced and stable, which is required for optimum functioning. </li></ul><ul><li>Disruption of homeostasis by harmful agnents may cause disease. </li></ul>
  15. 15. 2) Process of damage and anti-damage <ul><li>Any disease is a process full of battle between damage and anti-damage. </li></ul><ul><li>The contrast between strength of damage and anti-damage determine the development of a disease. </li></ul>
  16. 16. renin angiotensinogen Angiotensin Ⅰ Angiotensin Ⅱ Increased water and sodium reaborption ↑ effective circulatory blood volume hemorrhage ↓ effective circulatory blood volume ↓ Renal artery pressure ↓ GFR->↓Na + at macula densa ↑ Sympathetic nerve glomerulus Juxtaglomerular cells Converting enzyme + Organ ischemia, dysfunction damage (JG cells) Adrenal cortex
  17. 17. 3) Reversal rule of cause and result Primary cause Result (cause) Further alteration Secondary alteration (cause) (+) (-)
  18. 18. Severe hemorrhage ↓ Cardiac output ↓ Blood pressure ↑ Symphathetic nerve ↑ catecholamine Constriction of Microartery & microvein Tissue hypoxia acidosis Re-open of capillary Blood stagnant in microcirculation ↓ Blood volume returned to heart + ↓↓ BP v i c o u s i c y c l e
  19. 19. 4) Correlation between systemic and local regulations Systemic alteration Local alteration disease Neural-humoral regulation Neural-humoral regulation
  20. 20. Furuncle, Local inflammation Systemic reaction of fever and elevated leukocyte Systemic metabolic disorder caused by diabetes mellitus furuncle
  21. 21. (2) Fundamental mechanisms for diseases <ul><li>1) Neural mechanism </li></ul><ul><li>2) Humoral mechanism </li></ul><ul><li>3) Cellular mechanism </li></ul><ul><li>4) Molecular mechanism </li></ul>
  22. 22. <ul><li>Alteration of neural system is tightly related with pathogenesis of disease. </li></ul><ul><li>The alterations of neural system induced by pathogens include: </li></ul><ul><ul><li>Direct injury of neural system (e.g. type B encephalitis) </li></ul></ul><ul><ul><li>Change of neural reflex (e.g. Parkinson’s disease) </li></ul></ul><ul><ul><li>Change of metabolism of neural cells (e.g. Alzheimer’s disease) </li></ul></ul><ul><li>Among neural mechanism, sympathetic system is of important role. </li></ul><ul><ul><li>Sympathetic nerve participates in many pathologic processes, e.g. edema, stress, shock </li></ul></ul>1) Neural mechanism
  23. 23. Sympathetic system <ul><li>Distribution of sympathetic system </li></ul><ul><li>Organs of head, neck, trunk, & external genitalia </li></ul><ul><li>Adrenal medulla </li></ul><ul><li>• Sweat glands in skin </li></ul><ul><li>• Arrector muscles of hair </li></ul><ul><li>• All vascular smooth muscle </li></ul>
  24. 24. 2) Humoral mechanism <ul><li>Humoral dysfunction indicates the alterations in number and activities of some humoral factors. </li></ul><ul><li>Humoral factors include: </li></ul><ul><ul><li>Hormones (i.e. Renin-Angiotensin-Aldosterone system, ADH ) </li></ul></ul><ul><ul><li>Chemical mediators (i.e. histamine, prostaglandin) </li></ul></ul><ul><ul><li>Cytokines (i.e. interleukines, tumor necrosis factors) </li></ul></ul><ul><li>Function manner of humoral factors include: </li></ul><ul><ul><li>Endocrine </li></ul></ul><ul><ul><li>Paracrine </li></ul></ul><ul><ul><li>Autocrine </li></ul></ul><ul><ul><li>intracrine </li></ul></ul>?
  25. 25. Renin Regulation of Renin-Angiotensin-Aldosterone system Decreased blood pressure Angiotensin Ⅰ Angiotensin Ⅱ Aldosterone Decreased urine volume conserves blood pressure
  26. 26. Regulation and effect of ADH Osmoreceptors Increased osmotic pressure Baroreceptors (aortic arch, carotid sinus) Decrease blood pressure Neurosecretory cell Posterior pituitory vasoconstriction Blood vessel Increased blood volume and increased blood pressure kidney Increased reabsorption of water ADH
  27. 27. <ul><ul><li>Endocrine action : the hormone is distributed in blood and binds to distant target cells. Paracrine action : the hormone acts locally by diffusing from its source to target cells in the neighborhood. Autocrine action : the hormone acts on the same cell that produced it. </li></ul></ul>Manners with which humoral factors exerts its function
  28. 28. Neural-humoral regulation endocrine glands neural system effect one loop of neural system
  29. 29. <ul><li>For example: </li></ul><ul><li>Sympathetic nerve excites->increased secretion of epinephrine and norepinephrine by medulla of adrenal gland -> α 、 ß receptors excitation in cardiac vascular system -> heart rate↑ and blood vessels contract -> BP↑ </li></ul>
  30. 30. 3) Cellular mechanism <ul><li>Cell damage </li></ul><ul><ul><li>Some pathogens destroy the cells with no selection, i.e. strong acid and alkali </li></ul></ul><ul><ul><li>Others attack cells selectively, i.e. hepatitis virus </li></ul></ul><ul><li>Selective damage of cells involves: </li></ul><ul><li>cell membrane Na + pump( Na + -K + -ATPase) -> cellular edema </li></ul><ul><li>Ca 2+ pump(Ca 2+ -ATPase) -> Ca 2+ overload </li></ul><ul><li>organelles mitochondrium-> ATP↓ </li></ul><ul><li>lysosome-> cell autolysis </li></ul>
  31. 32. 4) Molecular mechanism <ul><li>abnormal alteration at molecular level </li></ul><ul><ul><li>macro-molecule ->nucleic acid, protein </li></ul></ul><ul><ul><ul><li>Molecular disease </li></ul></ul></ul><ul><ul><ul><li>i.e. sickle cell anemia </li></ul></ul></ul><ul><ul><li>micro-molecule </li></ul></ul>
  32. 33. 4. Outcome of disease. <ul><li>Recovery </li></ul><ul><ul><li>Complete recovery : the pathological alterations are perfectly restored and the signs and symptoms of disease disappear entirely. </li></ul></ul><ul><ul><li>Incomplete recovery: the main symptoms disappear but some pathological changes are still there. </li></ul></ul><ul><ul><ul><li>i.e. myocardial infarction </li></ul></ul></ul><ul><li>Death </li></ul>
  33. 34. Death <ul><li>The body as a whole stop working forever </li></ul><ul><li>The cessation of heartbeats was used as criterion of death before. </li></ul><ul><li>The accepted definition of death now is brain death. </li></ul>
  34. 35. Brain Death ( WHO criteria ) <ul><li>Cessation of spontaneous respiration </li></ul><ul><li>Irreversible coma </li></ul><ul><li>Absence of cephalic reflexes </li></ul><ul><li>Dilated or fixed pupils </li></ul><ul><li>Absence of any electrical activity of the brain </li></ul><ul><li>Absence of brain blood flow </li></ul>
  35. 36. Significance for diagnosis of brain death <ul><li>In favor of recording the time of death </li></ul><ul><li>Define the time to terminate for the rescue </li></ul><ul><li>In favor of organ transplantation </li></ul>
  36. 38. review <ul><li>Concept of disease </li></ul><ul><ul><li>Disease ※ , health, sub-health </li></ul></ul><ul><li>Etiology of disease </li></ul><ul><ul><li>Causative factors </li></ul></ul><ul><ul><li>Predisposing and precipitating factors </li></ul></ul><ul><li>Pathogenesis of disease </li></ul><ul><ul><li>General rule </li></ul></ul><ul><ul><ul><li>Disruption of homeostasis </li></ul></ul></ul><ul><ul><ul><li>Damage and anti-damage </li></ul></ul></ul><ul><ul><ul><li>Alternation of cause and result </li></ul></ul></ul><ul><ul><ul><li>Correlation of System and local </li></ul></ul></ul><ul><ul><li>Fundamental mechanism </li></ul></ul><ul><ul><ul><li>Neural mechanism </li></ul></ul></ul><ul><ul><ul><li>Humoral mechanism </li></ul></ul></ul><ul><ul><ul><li>Cellular mechanism </li></ul></ul></ul><ul><ul><ul><li>Molecular mechanism </li></ul></ul></ul>
  37. 39. <ul><li>The alterations of neural system </li></ul><ul><ul><li>Direct injury of neural system, i.e. </li></ul></ul><ul><ul><ul><li>Type B encephalitis </li></ul></ul></ul><ul><ul><li>Change of neural reflex and metabolism of neural cells, i.e. </li></ul></ul><ul><ul><ul><li>Exciting of sympathetic nerve -> release of catecholamine->biological effects; </li></ul></ul></ul><ul><ul><ul><li>Alzheimer’s disease -> β - amyloid peptide accumulation in brain cell </li></ul></ul></ul>1) Neural mechanism
  38. 40. <ul><li>alterations in number and activities of humoral factors. </li></ul><ul><ul><li>Hormones (i.e. Renin-Angiotensin-Aldosterone system, ADH ) </li></ul></ul><ul><ul><li>Chemical mediators (i.e. histamine, prostaglandin) </li></ul></ul><ul><ul><li>Cytokines (i.e. interleukines, tumor necrosis factors) </li></ul></ul>2) Humoral mechanism
  39. 41. <ul><li>Function manner of humoral factors include: </li></ul><ul><ul><li>Endocrine </li></ul></ul><ul><ul><li>Paracrine </li></ul></ul><ul><ul><li>Autocrine </li></ul></ul><ul><ul><li>intracrine </li></ul></ul>
  40. 42. 3) Cellular mechanism <ul><li>Cell damage </li></ul><ul><ul><li>cell membrane </li></ul></ul><ul><ul><ul><li>Na + pump </li></ul></ul></ul><ul><ul><ul><li>Ca 2+ pump </li></ul></ul></ul><ul><ul><li>Cell organelles </li></ul></ul><ul><ul><ul><li>Mitochondrium </li></ul></ul></ul><ul><ul><ul><li>lysosome </li></ul></ul></ul>