1b// Kidney Function

Question 1

If a patient is dehydrated, the filtrate present in which of these areas will have the highest osmolarity?

Answer 1

loop of henle

Question 2

The urine samples of different patients were analysed using the urine osmolarity test. Whose sample is likely to have the highest osmolarity?

Patient with loss-of-function V2 receptor mutation

Patient suffering from central diabetes insipidus

Patient with loss-of-function UT-B1 urea transporter mutation

Patient suffering from hepatic cirrhosis

Answer 2

Patient suffering from hepatic cirrhosis

Question 3

An athlete after finishing their London Marathon run drank 2L of distilled water. Which of the following statement is correct about their body fluids?

Decrease in Extracellular Fluid (ECF) volume.

Decrease in plasma osmolarity

Decrease in Intracellular Fluid osmolarity

Decrease in interstitial fluid volume

Answer 3

Decrease in plasma osmolarity

Question 4

The increase in plasma concentration of which solute will have no effect on ADH production?

glucose
urea
salt
ethanol

Answer 4

urea

Question 5

Sodium excretion is very limited (less than 1% of filtered load) and several mechanisms exist to tightly regulate it. Increasing sodium excretion reduces water retention. Potassium excretion can vary over a very large range (from 1 to 80% of filtered load). Why doesn’t this variability in potassium excretion have a marked effect on water balance?

Answer 5

The amount of potassium in the plasma and extracellular is much lower than the amount sodium so that variations in this amount are insufficient to have a marked effect on water balance.

Question 6

Why do most diuretics increase potassium excretion?

Answer 6

The increase in flow rate is detected in the collecting duct and directly stimulates potassium excretion.

Question 7

Mr Holmes (65 years old, 75 Kg) is being treated with a loop diuretic and Mr Smith (66 years old, 74 Kg) with a thiazide diuretic for past 3 weeks (assume that the doses of the respective treatments allow an equivalent inhibition of [Na+] reabsorption). Both the individuals are drinking insufficient but equivalent amount of water. Which of the following statement is likely to be true?

Answer 7

Mr Holmes urine will have lower osmolarity than Mr Smiths.

Question 8

Ms S, a 25-year-old woman while trekking the Himalayas develops symptoms of dizziness and pain. Following data was collected for her: Blood pH = 7.6, [HCO3-] = 16mEq/L, PCO2 = 25mmHg. Identify her acid-base disorder.
[Normal values: Blood pH = 7.4, [HCO3-] = 24mEq/L, PCO2 = 40mmHg]

Answer 8

Respiratory alkalosis

Question 9

Ms L, a 25-year-old healthy woman on her holiday develops stomach infection with nausea and vomiting. Following data was collected for her: Blood pH = 7.1, [HCO3-] = 16mEq/L, PCO2 = 30mmHg. Identify the compensatory mechanism being used by her body. [Normal values: Blood pH=7.4, [HCO3-] = 24mEq/L, PCO2 = 40mmHg]

Answer 9

Respiratory compensation – Hyperventilation

Question 10

Ms J, a 25-year-old woman with a history of asthma, on her holiday develops stomach infection with diarrhoea. Following data was collected for her: Blood pH = 7.1, [HCO3-] = 16mEq/L, PCO2 = 45mmHg. Identify her acid-base disorder.
[Normal values: Blood pH = 7.4, [HCO3-] = 24mEq/L, PCO2 = 40mmHg]

Answer 10

Mixed acidosis