Week 5 - Fluid and Electrolyte Balance

Question 1

What type of mechanisms are in place to maintain optimal fluid balance in a variety of conditions?

Answer 1

• homeostatic mechanisms

Question 2

Water or fluid in the body is in one of which three compartments?

Answer 2

1. plasma (in our blood vessels, also called the vascular space)
2. In the interstitial space
   - fluid is in the space between cells
3. In the intracellular space
   - the fluid in the space inside cells

Question 3

How much water/fluid is in plasma?

Answer 3

• 3L

Question 4

How much water/fluid is in interstitial fluid (IF)?

Answer 4

10 L

Question 5

How much water/fluid is in the intracellular fluid (ICF)?

Answer 5

• 28 L

Question 6

For electrolyte distribution, we will focus mainly on sodium and potassium. The body is designed to keep these specific concentrations to maintain homeostasis. Where can you find most Na+ and most K+ in the compartments? How about little?

Answer 6

Most Na+ - Plasma (blood)
little Na+ - Intracellular

Most K+ - Intracellular
Little K+ - Plasma

note that Na+ likes to slip in plasma, and little K+ in the plasma is what bloodwork measures

Question 7

Sodium is an _____ (intracellular/Extracellular) electrolyte, while potassium is an ______ (intracellular/extracellular) electrolyte.

Answer 7

sodium is an extracellular electrolyte
Potassium is an intracellular electrolyte

Question 8

When we draw labs, where can we only measure the concentration of sodium and potassium? Why?

Answer 8

• in the blood
• easier to measure because hard to measure amounts inside cells

Question 9

If we get labs for serum potassium (K+), what is the reference range?

Answer 9

• 3.5-5 mmol/L

Question 10

If we get labs for serum sodium (Na+), what is the reference range?

Answer 10

• 135-145 mmol/L

Question 11

If all the electrolytes are within normal range, what warning signs would there me if it was not WNL?

Answer 11

• fluid volume excess or fluid volume deficits

Question 12

What does hemoglobin and hematocrit in normal range show optimal levels of? (2)

Answer 12

• body water present in the blood
• no hemodilution or hemoconcentration occurring

Question 13

What is the significance of albumin in the plasma? (3)

Answer 13

• it stays in the plasma
• proteins pull water to it
• water follows them
  no protein means fluid going out