Medical Surgical Nursing Fluid and Electrolyte Exam
Diffusion
Answer: Movement of molecules from high to low concentration. Requires no energy. Occurs in liquids,
solids, and gases
Facilitated Diffusion
Answer: Movement of molecules from high to low concentration without energy
Active transport
Answer: Process of which molecules move against concentration gradient
Example: Sodium-potassium pump
External energy required
Osmosis
Answer: Movement of water between two compartments by a membrane permeable to water but not
solute
Moves from low solute to high solute concentration
Requires no energy
Osmotic pressure
Answer: Amount of press required to stop osmotic flow of water
Determined by the concentration of solutes in solution (sodium & glucose)
Oncotic Pressure
Answer: Osmotic pressure exerted by colloids in solution. Protein is a major colloid.
What are three substances that primarily determine water movement in the body?
Answer: Protein, glucose, and sodium
Edema
Answer: Caused by an accumulation of fluid in the interstitial space, occurs if venous hydrostatic
pressure rises, plasma oncotic pressure decreases, or interstitial oncotic pressure rises.
Decrease plasma oncotic pressure
Answer: Fluid remains in the interstitial space if the plasma oncotic pressure is too low to draw back into
the capillary. Low plasma protein content decreases oncotic pressure. This can result from excessive
protein loss (renal disorders), deficient protein synthesis (liver disease) and deficient protein intake
(malnutrition)
Elevation of venous hydrostatic pressure
Answer: Increasing the pressure at the venous end of the capillary inhibits fluid movement back into the
capillary, which results in edema. Causes include: fluid overload, HF, liver failure, obstruction of venous
return to the heart... ect.
Diffusion
Answer: Movement of molecules from high to low concentration. Requires no energy. Occurs in liquids,
solids, and gases
Facilitated Diffusion
Answer: Movement of molecules from high to low concentration without energy
Active transport
Answer: Process of which molecules move against concentration gradient
Example: Sodium-potassium pump
External energy required
Osmosis
Answer: Movement of water between two compartments by a membrane permeable to water but not
solute
Moves from low solute to high solute concentration
Requires no energy
Osmotic pressure
Answer: Amount of press required to stop osmotic flow of water
Determined by the concentration of solutes in solution (sodium & glucose)
Oncotic Pressure
Answer: Osmotic pressure exerted by colloids in solution. Protein is a major colloid.
What are three substances that primarily determine water movement in the body?
Answer: Protein, glucose, and sodium
Edema
Answer: Caused by an accumulation of fluid in the interstitial space, occurs if venous hydrostatic
pressure rises, plasma oncotic pressure decreases, or interstitial oncotic pressure rises.
Decrease plasma oncotic pressure
Answer: Fluid remains in the interstitial space if the plasma oncotic pressure is too low to draw back into
the capillary. Low plasma protein content decreases oncotic pressure. This can result from excessive
protein loss (renal disorders), deficient protein synthesis (liver disease) and deficient protein intake
(malnutrition)
Elevation of venous hydrostatic pressure
Answer: Increasing the pressure at the venous end of the capillary inhibits fluid movement back into the
capillary, which results in edema. Causes include: fluid overload, HF, liver failure, obstruction of venous
return to the heart... ect.
