physioex 10

• acid-base balance: pH of a body's fluid
• acid release hydrogen ions
• bases bind or buffer hydrogen
• strong base: a base that can accept a large amount of hydroxide ions
• weak acid: an acid that releases only small amounts of hydrogen ions
• strong acids release all its hydrogens
• weak base less hydrogen bonding, less effect on pH
• normal pH range is 7.35-7.45
• normal range PCO2 35-45 mmHg
• respiratory alkalosis is when too little CO2 is in the blood; causes are high altitude or hyperventilation
• renal system compensated for alkalosis by retaining H and excreting bicarb ions to lower blood pH and vice versa for acidosis
• respiratory acidosis results from impaired respiration or hypoventilation, leading to excess CO2 in blood; caused by airway obstruction, depression of respiratory center in brain stem, emphysema and chronic bronchitis, and drug overdose
• metabolic acidosis occurs due to increased production of acid (lactic acid) or loss of bicarbonate ions (diarrhea); can be caused by diabetic ketoacidosis, kidney failure, alcoholism, and starvation
• compensation for metabolic acidosis includes respiratory system increasing ventilation rate to blow off more CO2 and increase pH
• rebreathing creates CO2 accumulation in the blood
• kidneys regulate acid-base balance by altering H and bicarb excreted in urine
• metabolic alkalosis occurs due to ingestion of antacids or bicarb, vomiting (expels H), constipation (reabsorption of bicarb)
• increase in normal metabolic rates cause more CO2 to form as waste product, lowering plasma pH and causing acidosis
• decrease in normal metabolic rate forms less CO2 as waste and less H made, raising plasma pH and causing alkalosis
• fever, stress or food ingestion raise metabolism
• fall in body temp or decreased food intake lowers cell metabolism
• functional unit for adjusting plasma composition is nephron
• pH and bicarb increases with a decreased metabolism