26. Fluid and Electrolyte Balance, Acid Base Balance

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.

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).

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

d. Atrial natriuretic peptide promotes water retention in the kidneys and increases the amount of water in the body.

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

e. Dehydration is characterized by a decreased volume and increased osmolarity of the ECF.

Which of the following statements best describes the principle of mass balance?

a. The amount of a variable that is gained by the body through ingestion equals the amount that is lost from the body.

b. The body maintains a stable mass at all times.

c. The amount of each variable brought into the body must be balanced by all other variables.

d. The amount of a variable ingested is regulated by a positive feedback loop.

As a percentage of body weight, the total body water tends to be higher in ________ and lower in ________ .

a. infants; men

b. women; men

c. men; infants

d. infants; women

How does angiotensin-II help to restore fluid balance when a person is dehydrated?