Physio/ganong

Front 1

What is Conn's syndrome?

Back 1

It is a primary excessive secretion of aldosterone, and it would be associated with marked hypokalemia and metabolic alkalosis(increased plasma pH).

Front 2

Does aldosterone stimulate sodium reabsorption and potassium excretion by the cortical collecting tubule?

Back 2

Yes.

Front 3

Does a doubling of plasma creatinine imply that the creatinine clearance and glomerular filtration rate have been reduced by app. 50%?

Back 3

Yes. Although the reduction in creatinine clearance would initially cause a transient decrease in filtered load of creatinine, creatinine excretion rate, and sodium excretion rate, the plasma concentration of creatinine would increase until the filtered load of creatinine and the creatinine excretion rate returned to normal.

Front 4

How is creatinine clearance defined?

Back 4

It is the urinary excretion rate of creatinine of creatinine divided by the plasma creatinine concentration.

Front 5

What is the glomerular capillary filtration coefficient?

Back 5

It is the product of the hydraulic conductivity and surface area of the glomerular capillaries.

Front 6

Increasing the glomerular capillary filtration coefficient tends to increase GFR. TRUE/FALSE

Back 6

TRUE.

Front 7

List 4 intracapsular conditions that tend to decrease GFR.

Back 7

1. Increased afferent arteriolar resistance.
2. Decreased efferent arteriolar resistance.
3. Increased Bowmans capsule hydrostatic pressure.
4. Decreased glomerular hydroststic pressure.

Front 8

Complete renal clearance of a substance would require both glomerular filtration and tubular secretion of that substance. TRUE/FALSE

Back 8

TRUE. The total amount of substance delivered to the kidneys in the blood(renal plasma flow X concentration of substance in the blood) would equal the amount of that substance excreted in the urine.

Front 9

A patient has the following lab values:
Arterial pH= 7.25
Plasma HCO3= 13mEq/L
Plasma chloride conc= 118mEq/L
Arterial PCO2= 30mm/Hg
Plasma Na+ conc= 141mEq/L
What is the most likely cause of his acidosis?

Back 9

Diarrhea. Because the plasma HCO3 conc is also lower than normal, the patient has metabolic acidosis with respiratory compensation(PCO2 is lower than normal) Plasma anion gap(Na+-Cl- and HCO3 = 10mEq/L) is in the normal range, suggesting that the metabolic acidosis is not caused by excess nonvolatile acids such as salicylic acid or ketoacids caused by diabetes mellitus. Therefore the most likely cause is diarrhea, which would indeed cause a loss of HCO3, in the feces and would be associated with a normal anion gap and a hyperchloremic metabolic acidosis.

Front 10

What would be the metabolic result of excessive ingestion of salicylic acid(aspirin)?

Back 10

It would cause metabolic acidosis, given by reductions in plasma HCO3 concentration and increased plasma anion gap.
The acidosis stimulates respiration, causing a compensatory decrease in plasma PCO2. The acidosis also increases renal absorption of HCO3, resulting in decreased urine HCO3 excretion. The acidosis would as well stimulate a compensatory increase in renal tubular NH4+ production.

Front 11

Urine flow rate is equal to GFR minus tubular fluid reabsorption rate. Therefore, if GFR is reduced to 50ml/min and tubular reabsorption rate is also 50ml/min, urine flow rate will be zero. TRUE/FALSE

Back 11

True.

Front 12

A large increase in aldosterone secretion combined with a high sodium intake would cause severe hyperkalemia. TRUE/FALSE

Back 12

TRUE. Aldosterone stimulates K+ secretion and causes a shift of potassium from the ECF into the cells, and a high Na+ intakes increases the collecting tubular flow rate, which also enhances K+ secretion.

Front 13

What is the association between acidosis and diabetes mellitus?

Back 13

It results in increased blood acetacetic acid levels, which in turn cause metabolic acidosis and decreased plasma HCO3- and pH. This will increase the respiratory rate, which reduces plasma PCO2, increased renal NH+ production which leads to increased NH+ excretion, and increased phosphate buffering of H+ ions secreted by the renal tubules, which increases titratable acid excretion.