In response to excess water in the body, 

(a) Antidiuretic hormone is secreted by the anterior lobe of the pituitary gland.

(b) The active transport mechanisms in the ascending thick limb of the nephron loop cease functioning.

(c) The permeability of the distal convoluted tubules and collecting ducts to water is decreased.

(d) The permeability of the ascending limb of the nephron loop is increased.

(e) The glomerular filtration rate is reduced.

Dan has been lost in the desert for 2 days with very little water. As a result of this exposure, you would expect to observe which of the following? 

(a) Increased ADH levels

(b) Decreased blood osmolarity

(c) Normal urine production

(d) Increased blood volume

(e) Cells enlarged with fluid

Sylvia is suffering from severe edema in her arms and legs. Her physician prescribes a diuretic (a substance that increases the volume of urine produced). Why might this help alleviate Sylvia’s problem?

Mary, a nursing student, has been caring for burn patients. She notices that they consistently show elevated levels of potassium in their urine and wonders why. What would you tell her?

David’s grandfather suffers from hypertension. His doctor tells him that part of his problem stems from renal arteriosclerosis. Why would this cause hypertension?

While visiting a foreign country, Milly inadvertently drinks some water, even though she had been advised not to. She contracts an intestinal disease that causes severe diarrhea. How would you expect her condition to affect her blood pH, urine pH, and pattern of ventilation?

Yuka is dehydrated, so her physician prescribes intravenous fluids. The attending nurse becomes distracted and erroneously gives Yuka a hypertonic glucose solution instead of normal saline. What effect will this mistake have on Yuka’s plasma ADH levels and urine volume?

The drug Diamox is sometimes used to treat mountain sickness. Diamox inhibits the action of carbonic anhydrase in the proximal convoluted tubule. Polyuria (excessive urine production resulting in frequent urination) is a side effect associated with the medication. Why does polyuria occur?

Refer to the diagnostic flowchart in Spotlight Figure 27–18. Use information from the blood test results in the accompanying table to categorize the suspected acid-base disorders of the patients represented in the table.

<IMAGE>