26. Fluid and Electrolyte Balance, Acid Base Balance

Body water content is greatest in:

a. Infants

b. Young adults

c. Elderly adults

Water balance is regulated by control of amount(s):

a. Ingested

b. Excreted in urine

c. Lost in perspiration

d. Lost in feces

Two substances regulated by parathyroid hormone are:

a. Ammonium ions

b. Bicarbonate

c. Calcium

d. Chloride

e. Hydrogen ions

f. Magnesium

g. Phosphate

h. Potassium

i. Sodium

j. Water

Part of an important chemical buffer system in plasma is:

a. Ammonium ions

b. Bicarbonate

c. Calcium

d. Chloride

e. Hydrogen ions

f. Magnesium

g. Phosphate

h. Potassium

i. Sodium

j. Water

Substance regulated by ADH's effects on the renal tubules is:

a. Ammonium ions

b. Bicarbonate

c. Calcium

d. Chloride

e. Hydrogen ions

f. Magnesium

g. Phosphate

h. Potassium

i. Sodium

j. Water

Which of the following factors will enhance ADH release?

a. Increase in ECF volume

b. Decrease in ECF volume

c. Decrease in ECF osmolality

d. Increase in ECF osmolality

Name the body fluid compartments, noting their locations and the approximate fluid volume in each.

Describe the thirst mechanism, indicating how it is triggered and terminated.

Explain why and how ECF osmolality is maintained.

Mr. Jessup, a 55-year-old man, is operated on for a cerebral tumor. About a month later, he appears at his physician's office complaining of excessive thirst. He claims to have been drinking about 20 liters of water daily for the past week and says he has been voiding nearly continuously. A urine sample is collected and its specific gravity is reported as 1.001.

What is your diagnosis of Mr. Jessup's problem?

What connection might exist between his previous surgery and his present problem?

A cell in a/an ________ fluid will lose water, and a cell in a/an ________ fluid will gain water.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

a. The thirst mechanism is mediated by osmoreceptors located in the cerebral cortex.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

b. The sensible water loss includes the water lost from the body via the skin and the respiratory system.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

c. The main hormone that regulates fluid balance is antidiuretic hormone (ADH).