(DSM6) Osmosis Flashcards
What is the equation for osmolarity?
DSA6 LO3
Osmolarity = g x [C]
Where:
g = the number of particles the solute dissociates into in solution
[C] = the molarity of the solute
What do the terms isosmotic, hyposmotic, and hyperosmotic mean?
DSM6 LO3
Isosmotic:
-solution in question has the same osmolality as the solution it is being compared to
Hyposmotic:
-solution in question has a lower osmolality than the solution being compared to
Hyperosmotic:
-solution in question has a higher osmolality than the solution being compared to
What is the reflection coefficient?
What is its range and what does its value indicate?
DSA LO3
Reflection coefficient represents a solutes premeability to a cell membrane.
Values range from 0 to 1 with 0 being completely permeable and 1 being not permable at all.
What is the average osmolality of the human body and what is the normal range?
DSA6 LO3
Average:
-290 mOsm
Normal range:
-270-300 mOsm
What solution of sodium chloride is isosmotic to the human body?
DSA6 LO3
0.9% NaCl, also refered to as normal saline
What is the formula for estimated osmolality?
DSA6 LO4
Estimated osmolality = 2[Na] + [glucose]/18 + [BUN]/2.8
What happens to a cell with normal osmolarity when exposed to a solution that is isosmotic, hyposmotic, and hyperosmotic?
DSA6 LO5
Isosmotic:
-cell volume unchanged
Hyposmotic:
-cell volume increases
Hyperosmotic:
-cell volume decreases
What do isotonic, hypotonic, and hypertonic mean?
How does tonicity relate to osmolarity?
DSA6 LO6
Isotonic:
-will not affect the volume of an RBC
Hypotonic:
-will increase the volume of an RBC
Hypertonic:
-will decrease the volume of an RBC
Tonicity and osmolartiy are similar if the reflection coefficient of the solute is close to 1. They are disimilar if the refelction coefficient is close to 0.