A nurse in the medical ICU has orders to infuse a hypertonic solution into her patient with low blood pressure

Question

This solution will increase the number of dissolved particles in the patient's blood, creating pressure for fluids in the tissues to shift into the capillaries and increase the blood volume. Which term or terms is/are associated with this process?
A) Hydrostatic pressure
B) Osmosis and osmolality
C) Diffusion
D) Active transport

Answer 1

Ans: B
Feedback: Osmosis is the movement of fluid from a region of low solute concentration to the region of high solute concentration across a semipermeable membrane. The number of dissolved particles contained in a unit of fluid determines the osmolality of a solution, which influences the movement of fluid between the fluid compartments. Giving a patient who has a low blood pressure a hypertonic solution will increase the number of dissolved particles in the blood, creating pressure for fluids in the tissues to shift into the capillaries and increase the blood volume. Option A is incorrect; hydrostatic pressure refers to changes in water or volume related to water pressure. Option C is incorrect; diffusion is the movement of solutes from an area of greater concentration to lesser concentration; the solutes in an intact vascular system are unable to move so diffusion normally should not be taking place. Option D is incorrect; active transport is the movement of molecules against the concentration gradient and requires ATP as an energy source; this process typically takes place at the cellular level and is not involved in vascular volume changes.