A hormone formed in the blood that causes vasoconstriction is:

1. Renin	2. Aldosterone
3. Angiotensin	4. Vasopressin

The collecting ducts become permeable to water and urea due to:

Identify the correct statement regarding human kidney function if ADH is not secreted in the body:
1. Urine will be isoosmotic with plasma.
2. PCT will not be able to reabsorb water and sodium.
3. The collecting ducts have very low permeability to water.
4. The distal tubules secrete water.

The urine examination of a person suspected of a kidney disorder is most likely to show the presence of:

Total body water in humans makes up between 45 to 75% of total body weight. About two thirds of this is:
1. Extracellular fluid
2. Interstitial fluid
3. Intracellular fluid
4. Plasma

Intracellular fluid:
1. has a lower concentration of potassium than extracellular fluid.
2. has a lower concentration of sodium ions than extracellular fluid.
3. does not remain in osmotic equilibrium.
4. has a higher concentration of calcium ions than extracellular fluid.

The principal cation in the extracellular fluid is:

Increased stretching of the atrial wall, due to increased atrial blood volume, stimulates the release of:

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

The humoral stimulus for the secretion of aldosterone is:
1. elevated blood ${\mathrm{Na}}^{+}$ ion levels.
2. decreased blood ${\mathrm{Cl}}^{-}$ ion levels.
3. elevated blood ${\mathrm{K}}^{+}$ ion levels.
4. decreased blood ${\mathrm{Ca}}^{2+}$ ion levels.