Body Fluid Compartments

Question 1

Define Isooncotic

Answer 1

Same amount of albumin, for human 1 mM of albumin/L plasma

Question 2

Define Isosmotic

Answer 2

Same number of ions

Question 3

Isotonic

Answer 3

Same solute and solution concentration

Question 4

Define Osmotic pressure

Answer 4

The hydrostatic pressure required to prevent fluid from leaving a compartment

Question 5

What is the osmolarity of plasma?

Answer 5

292 millimoles solute/Liter

Question 6

What is the role of Albumin?

Answer 6

Carries fatty acids,Ca+ and acts as a H+ buffer

Question 7

What is the concentration of Cl- in plasma? Na+, Bicarb?

Answer 7

103, 140, 27

Question 8

What is the typical range for anion gap?

Answer 8

10-14

Question 9

Describe milliosmoles

Answer 9

millimoles of total free solute

Question 10

What is the difference between Osmolarity and Osmolality?

Answer 10

Osmolarity is millimoles/Liter and Osmolality / Kg

Question 11

Why is the reference osmolatity 292 and not the calculated 300?

Answer 11

Some Ca+ and albumin are bound which reduces osmolatlity.

Question 12

What is the equation for fluid movement across a semi-permeable membrane?

Answer 12

K(Pc+pi(if))-(Pif+pi(c)) where P = hydrostatic and pi = osmotic.

Question 13

When you drink water where does it go?

Answer 13

To all 3 compartments in the corresponding volume ratio.

Question 14

Describe what happens when you give a normal saline infusion?

Answer 14

Distributes to the plasma and interstitial fluid in the corresponding ratio of body water. Does not enter cells becuase of Na/K pumps

Question 15

Describe what happens when you give 1/2 normal saline?

Answer 15

half distributes as water and the other half (the saline part) distributes to the Plasma and ISF.

Question 16

Describe what happens when you give isoncotic saline? Also called artifical plasma

Answer 16

It distributes just in the plasma but does leave to ISF via hydrostatic pressure and return via oncotici pressure.

Question 17

Describe what happens when you give a person 5% dextrose?

Answer 17

It distributes into all 3 compartment as Glucose gets oxidized or is converted to glycogen or fat. The fluid distributes in ratio equal to TBW.