Sodium is the principal cation in blood. If the blood concentration of sodium ions gets below normal:
1. blood volume increases and blood pressure decreases
2. water drains from the collecting duct
3. blood volume and blood pressure decrease
4. ADH secretion increases

The urinary clearance of a substance is found to be less than its glomerular filtration rate. This substance most likely:
1. is filtered and is not subject to reabsorption or secretion
2. is filtered and is partially reabsorbed
3. is filtered and is partially secreted
4. is totally secreted

Serum potassium concentrations are the most potent stimulator of secretion of:
1. Aldosterone
2. Angiotensin II
3. ADH
4. Atrial natriuretic hormone

Which of the following contributes maximum to the buffer capacity of human body?
1. carbonic acid/bicarbonate buffer system.
2. phosphate buffer system.
3. protein buffer system.
4. oxygen/carbondioxide buffer system.

Patients with uncontrolled diabetes mellitus are most likely to develop complications like:
1. respiratory acidosis and retention of body fluid.
2. respiratory alkalosis and dehydration.
3. metabolic acidosis and dehydration.
4. metabolic alkalosis and dehydration.

What would be the logical consequence of an increased hydrogen ion concentration of the ECF?
1. An increase in ECF pH.
2. A slower respiratory rate.
3. An increase in urinary pH.
4. An increase in hydrogen ion secretion by kidney.

The perinephric fat:
1. is the storage energy for renal functions.
2. is the renal capsule.
3. cushions the kidney from mechanical shock.
4. is present only under pathological conditions.

A substance like inulin is readily filtered at the glomerulus but is not reabsorbed or secreted in the tubules. The renal clearance rate of inulin:

1. equals the GFR.

2. is always greater than the GFR.

3. is less than the GFR.

4. does not affect the GFR.

Renal threshold denotes

1. the percent of the cardiac output received by the kidneys per minute.

2. the amount of filtrate formed in all the nephrons of both kidneys per minute.

3. the plasma concentration at which reabsorption mechanisms are saturated and the molecule appears in urine.

4. the plasma concentration at which a substance starts getting filtered at the glomerulus.

Polysaccharide inulin is used to help measure kidney function by determining the glomerular filtration rate (GFR) because inulin is:

1. both filtered and secreted.

2. both filtered and reabsorbed.

3. filtered, but neither secreted nor reabsorbed.

4. only secreted.