Pathophysiology final study guide
Pathophysiology final study guide
COPD can lead to buildup of CO2 because you can’t expel it very well so your blood can be very acidic
- Leads to pulmonary acidosis
pH
● Normal pH of adult blood ranges from 7.35 to 7.45.
● High pH indicates few hydrogen ions.
○ Solution is alkaline (basic).
● Low pH indicates a lot of hydrogen ions.
○ Solution is acidic.
Acid-Base Homeostasis
● Three major mechanisms regulate acid-base status of the body.
○ Buffers
○ Respiratory system
○ Renal system
Buffers
● First line of defense against pH changes in all body fluids.
● Components
○ Weak acids that release hydrogen ions when a fluid is too alkaline
○ A base that takes up hydrogen when fluid is too acidic.
Bicarbonate Buffer System
● Primary defense against acid-base disorders
● Absorbs Hydrogen ions
● Components
○ Base: bicarbonate ions (HCO3− )
○ Weak acid: carbonic acid (H2CO3)
● Functions
○ Too much acid (e.g., lactic acid, acidic)
■ Bicarbonate ions take up hydrogen ions (H+) released by the acid; become carbonic acid
■ Carbonic acid released as carbon dioxide through the lungs
○ Too little acid (alkaline)
■ Bicarbonate buffers release hydrogen ions from the weak acid to increase
pH. Respiratory Contribution
● Second defense against acid-base disorders
● Lungs excrete CO2 and water from the body.
○ Rid the body of carbonic acid
● Change the rate of Breathing:
● Increased ventilation (hyperventilation) results in:
○ Decreased carbon dioxide in the blood
○ Thus reducing carbonic acid
,Pathophysiology final study guide
● Decreased ventilation (hypoventilation) results in:
○ Carbon dioxide accumulation
○ Thus increasing carbonic acid
Renal Contribution → Kidneys
,Pathophysiology final study guide
● Third defense against acid-base disorders
● Carbonic Acid handled by lungs → pulmonary acidosis can't get rid of CO2
● Bicarbonate and H ions is handled by Kidneys
● Kidneys hold onto Bicarbonate and get rid of H ions by peeing out H ions
● If kidneys are damaged → Metabolic acidosis; your kidneys can’t get rid of H+
● Can excrete any acid from the body except carbonic acid (solely excreted by the lungs)
● Excrete metabolic acids produced
continuously during normal metabolism
○ Increased excretion of hydrogen if a
metabolic acid begins to accumulate
in blood
○ Slows excretion of hydrogen if a
metabolic acid is deficient in blood
● Increased excretion of hydrogen
○ Increase production of ammonia
(NH3)
○ Hydrogen combines with ammonia
and is excreted in the urine.
● Slow excretion of hydrogen
○ Decrease production of ammonia
○ Excrete less H; reabsorb hydrogen back into the blood
○ Excrete bicarbonate
Metabolic Acidosis
● Increase in acid
○ Decreases normal ratio of bicarbonate to carbonic acid because bicarbonate ions are used up in
buffering the excess acid
Respiratory Acidosis
● Any condition that causes an excess of carbonic acid
● Caused by impaired removal of carbonic acid by the lungs
● Impaired gas exchange
○ Chronic obstructive pulmonary disease (COPD)
○ Pneumonia
○ Severe asthma
○ Pulmonary edema
○ Acute (adult) respiratory distress syndrome
Metabolic Alkalosis
● Decrease in acid
○ Emesis
○ Gastric suction
○ Mild or moderate extracellular fluid volume deficit
, Pathophysiology final study guide
■ Contraction alkalosis
○ Hyperaldosteronism
Pathophysiology final study guide
COPD can lead to buildup of CO2 because you can’t expel it very well so your blood can be very acidic
- Leads to pulmonary acidosis
pH
● Normal pH of adult blood ranges from 7.35 to 7.45.
● High pH indicates few hydrogen ions.
○ Solution is alkaline (basic).
● Low pH indicates a lot of hydrogen ions.
○ Solution is acidic.
Acid-Base Homeostasis
● Three major mechanisms regulate acid-base status of the body.
○ Buffers
○ Respiratory system
○ Renal system
Buffers
● First line of defense against pH changes in all body fluids.
● Components
○ Weak acids that release hydrogen ions when a fluid is too alkaline
○ A base that takes up hydrogen when fluid is too acidic.
Bicarbonate Buffer System
● Primary defense against acid-base disorders
● Absorbs Hydrogen ions
● Components
○ Base: bicarbonate ions (HCO3− )
○ Weak acid: carbonic acid (H2CO3)
● Functions
○ Too much acid (e.g., lactic acid, acidic)
■ Bicarbonate ions take up hydrogen ions (H+) released by the acid; become carbonic acid
■ Carbonic acid released as carbon dioxide through the lungs
○ Too little acid (alkaline)
■ Bicarbonate buffers release hydrogen ions from the weak acid to increase
pH. Respiratory Contribution
● Second defense against acid-base disorders
● Lungs excrete CO2 and water from the body.
○ Rid the body of carbonic acid
● Change the rate of Breathing:
● Increased ventilation (hyperventilation) results in:
○ Decreased carbon dioxide in the blood
○ Thus reducing carbonic acid
,Pathophysiology final study guide
● Decreased ventilation (hypoventilation) results in:
○ Carbon dioxide accumulation
○ Thus increasing carbonic acid
Renal Contribution → Kidneys
,Pathophysiology final study guide
● Third defense against acid-base disorders
● Carbonic Acid handled by lungs → pulmonary acidosis can't get rid of CO2
● Bicarbonate and H ions is handled by Kidneys
● Kidneys hold onto Bicarbonate and get rid of H ions by peeing out H ions
● If kidneys are damaged → Metabolic acidosis; your kidneys can’t get rid of H+
● Can excrete any acid from the body except carbonic acid (solely excreted by the lungs)
● Excrete metabolic acids produced
continuously during normal metabolism
○ Increased excretion of hydrogen if a
metabolic acid begins to accumulate
in blood
○ Slows excretion of hydrogen if a
metabolic acid is deficient in blood
● Increased excretion of hydrogen
○ Increase production of ammonia
(NH3)
○ Hydrogen combines with ammonia
and is excreted in the urine.
● Slow excretion of hydrogen
○ Decrease production of ammonia
○ Excrete less H; reabsorb hydrogen back into the blood
○ Excrete bicarbonate
Metabolic Acidosis
● Increase in acid
○ Decreases normal ratio of bicarbonate to carbonic acid because bicarbonate ions are used up in
buffering the excess acid
Respiratory Acidosis
● Any condition that causes an excess of carbonic acid
● Caused by impaired removal of carbonic acid by the lungs
● Impaired gas exchange
○ Chronic obstructive pulmonary disease (COPD)
○ Pneumonia
○ Severe asthma
○ Pulmonary edema
○ Acute (adult) respiratory distress syndrome
Metabolic Alkalosis
● Decrease in acid
○ Emesis
○ Gastric suction
○ Mild or moderate extracellular fluid volume deficit
, Pathophysiology final study guide
■ Contraction alkalosis
○ Hyperaldosteronism
