3. Renal Physiology - Bodily Fluid Compartments

Question 1

What compartments take on fluid in isoosmotic volume expansion?

Answer 1

ECF only

Question 2

What are the symptoms of hypernatremia?

Answer 2

Edema, increased blood pressure, muscular weakness, hyperactive reflexes, thirst, decreased urine output, confusion, and ultimately, coma.

Question 3

What is the normal NaCl concentration in blood?

Answer 3

0.85%

Question 4

Into what two categories can extracellular fluid be further divided?

What percentage of the extracellular fluid does each one represent?

Answer 4

Interstitial fluid makes up 75% of the extracellular fluid

Plasma makes up 25% of the extracellular fluid

Question 5

What are the symptoms of hyponatremia?

Answer 5

Disorientation, neurological disorders, weakness, muscle cramps, anorexia, nausea, and diarrhea.

Question 6

What two equations can be used to calculate osmolarity?

Answer 6

Osmolarity = 2(Na) + BUN/2.8 + Glucose/18

OR

2(Na)

Question 7

Which way does water flow in hypertonic dehydration?

Answer 7

From the ICF to the ECF

Question 8

What fluid compartment decreases in iso-osmotic volume contraction?

Answer 8

ECF (extracellular compartment)

Question 9

Which way does water flow in hypotonic dehydration?

Answer 9

From the ECF to the ICF

Question 10

What is the percentage concentration for an isotonic solution of glucose or dextrose to be administered intravenously?

Answer 10

5% glucose or dextrose

Question 11

Why does pitting edema occur in congestive heart failure?

Answer 11

Because the heart is failing to pump blood, which the body is interpreting as low blood pressure, causing sodium and water retention.

Question 12

What changes in the ECF volume will resulting in increased hematocrit?

What changes in ICF volume will result in increased hematocrit?

Answer 12

A decrease in ECF will cause a proportionate increase in red blood cells, leading to an increased hematocrit

An increase in ICF volume will cause the red blood cells to be larger and functionally increase hematocrit, even though there are the same number of red blood cells.

Question 13

Which compartments lose fluid in hyper-osmotic volume contraction?

Answer 13

ECF and ICF
Water loss from the ECF causes of the ECF to increase in osmolarity, also pulling water out of the ICF.

Question 14

What is the 60, 40, 20 rule?

Answer 14

60% of body weight is total body water

• *40%** of body weight is intracellular fluid
• *20%** of body weight is extracellular fluid

Question 15

What compartments take on fluid in hypo-osmotic volume expansion?

Answer 15

Both ICF and ECF