Author Question: A nurse is discussing the movement of fluid across the arterial end of capillary membranes into the ... (Read 146 times)

oliviahorn72 · **on:** Jun 25, 2018

A nurse is discussing the movement of fluid across the arterial end of capillary membranes into the interstitial fluid surrounding the capillary. Which process of fluid movement is the nurse de-scribing?

a. Hydrostatic pressure
b. Osmosis
c. Diffusion
d. Active transport

Question 2

A patient has a body fluid of 300 mOsm/kg. This lab result is measuring:

a. osmolality.
b. osmolarity.
c. osmotic pressure.
d. oncotic pressure.

jrpg123456 · **Reply #1 on:** Jun 25, 2018

Answer to Question 1

ANS: A
Blood reaching the capillary bed has a hydrostatic pressure of 2530 mm Hg, which is sufficient force to push water across the thin capillary membranes into the interstitial space. Osmosis in-volves the movement of fluid from an area of higher concentration to an area of lower concentra-tion. It does not involve pressure or force. Diffusion is the passive movement of a solute from an area of higher solute concentration to an area of lower solute concentration. Active transport in-volves movement up a concentration gradient.

Answer to Question 2

ANS: A
Osmolality measures the number of milliosmoles per kilogram of water, or the concentration of molecules per weight of water, while osmolarity measures the number of milliosmoles per liter of solution, or the concentration of molecules per volume of solution. Osmotic pressure is the amount of hydrostatic pressure required to oppose the osmotic movement of water. Oncotic pressure is from plasma proteins, not body fluids.