intro to Pathophysiology Quiz 1

• Fluid Balance:   equilibrium in water exchange between internal fluid compartments of the body and between the body and the external environment
• hypovolemia- extracellular volume depletion, water and electrolytes lost, decrease in intake of fluids, decrease in extracellular volume
• atrophy - decrease in size of cell; physiologic aging, stroke, starvation, cellular hypoxia/ischemia
• hypertrophy - increase in size of cell; increased tissue size, increased number of intracellular organelles
• hyperplasia - increase in number of cells; cells capable of dividing, sometimes considered normal (pregnancy)
• metaplasia - reversible change, one adult cell type is replaced by another adult cell type; chronic irritation and inflammation, protective functions are lost, may predispose cells to cancer
• dysplasia - precursor to cancer, cells have undergone atypical changes; possible reversal with removal of irritation or stimulus
• cell death - apoptosis, necrosis, gangrene
• apoptosis - programmed cell death, destroys cells no longer needed, associated with disease, pathology
• necrosis - cell death in a living organ or tissue that interferes with cell and tissue recognition
• gangrene - considerable mass of tissue undergoes necrosis due to lack of blood supply
• effects of stressors - diseases, aging, injury to the body
• adaptive changes - permit survival and maintain function
• stimuli causing cellular injury - ( usually reversible, stimulus is stopped if there is good nutrition and good blood supply ) physical agents, chemical agents, microorganisms, genetic defects, nutritional imbalances, hypoxia
• physical agents - trauma, temp changes, radiation, electrical stimulation, direct damage, local swelling
• chemical agents - simple compounds ( glucose ), complex ( toxins, therapeutic agents ), damage to the cell or taken into cell
• microorganisms - contribute to infections, secretion of toxins ( bacteria ), interfere with metabolism and ATP production, viruses cause cellular injury by releasing viral proteins
• genetic defects - inborn problems of metabolism, gross malformations ( defect in DNA, inherited )
• nutritional imbalances - self induced or disease induced, deficiencies of vitamins and proteins, excessive food intake of lipids and fats
• hypoxia - most common cause of cellular injury, inadequate oxygen to cells, decreased perfusion to tissues, may result in cell death
• pigments - colored substances that accumulate in cells
• melanin - changes in skin color
• hemoproteins - bruising
• hemosiderin - the iron rich pigment
• high concentration of hydrogen ions = low pH and acidosis
• low concentration of hydrogen ions = high pH and alkalosis
• normal pH - 7.35 - 7.45
• chemical buffer systems - bicarbonate buffer is the primary buffer, phosphate and ammonia buffers occur throughout he kidneys, intracellular and extracellular protein buffers can bind to or release hydrogen ions to change pH, potassium- hydrogen exchange will substitute the reabsorption's of potassium and secretion of hydrogen in the kidneys
• if there is acidosis, hydrogen will move into the cell and potassium moves out
• if there is alkalosis, more hydrogen will go out of the cell and potassium will go into the cell
• respiratory compensation - will kick in if metabolic is causing the abnormal pH, retaining or blowing off carbon dioxide, changes how the person breathes, increase breathing to blow out more carbon dioxide
• renal compensation - slower, retention / excretion of bicarbonate by the kidneys, elimination of excess hydrogen in the urine, production of new bicarbonate occurs to buffer the hydrogen
• acidosis - pH less than 7.35
• normal PCO2 - 35-45 mmHg
• carbonic acid - derived from carbon dioxide and bicarbonate
• metabolic acid - buffered by circulating basic compounds and excreted by kidneys
• normal HCO3- = 22-26
• respiratory acidosis - increase PCO2 and decrease pH, can be acute or chronic, directly related to rate and depth of respiration
• metabolic acidosis - deficit in base bicarbonate and decrease pH
• alkalosis - pH is greater than 7.45