Osmolarity and tonicity physio?
Classify the following solutions (according with the osmolarity and tonicity) Indicate how the body fluid compartment and osmolarity will change when 1 Liter of the following solutions is administered IV. (increase, decrease, no change)
i obligation a little help here...whats diff btwn osmolarity and tonicity?
a. 300 mM NaCl
b. 1.8% saline solution
c. 0.45% NaCl + 5% dextrose in river (D5W)
Answers:
I'll first say the diff between tonicity and osmolarity.
Tonicity is the concentration of ONLY non-penetrating solutes in a given solution.
Osmolarity refers to the concentration of BOTH non-penetrating and penetrating solutes contained by a solution.
I'll give an example to help clarify this:
Say you had a cell that (in the intracellular fluid) have 300 mOsm of NON-penetrating solute (such as NaCl) and 20 mOsm of penetrating solute (such as urea).
Let's also say that the extracellular fluid has one and only a 300 mOsm solution of non-penetrating solutes, and had an equal volume with the cell. In this case, the cell would be hyperosmotic relative to the ECF (because it contains 320 mOsm of solutes, compared to 300 mOsm contained within the ECF).
BUT, the cell would be isotonic with the ECF (because both have the same concentration of non-penetrating solutes). So, the cell would neither shrink nor swell because it is isotonic near the ECF. Only tonicity affects the diffusion of water from one compartment to another (which causes it to shrink or swell depending on the situation).
NOW let's say the ECF individual has 200 mOsm of non-penetrating solutes (and still had an equal volume as the cell). In this case, the cell would still be hyperosmotic, but presently it would also be hypertonic relative to the ECF solution. From the perspective of the ECF, the ECF would be hypotonic relative to the cell (because the ECF has a less concentration of NON-penetrating solutes than the cell). Because the ECF has smaller quantity solutes, but still the same volume, that means it has a greater concentration of marine than the ICF, and by way of osmosis, a net flow of water from the ECF to the cell would materialize (causing the cell to swell). Does that help? If you need more explanation, drop me an email.
Now, let's answer your questions. I'm assuming "body fluid compartment" refers to the ECF. Assume the cell in general has a 300 mOsm solution of NaCl.
a.) Let me first say that there's a diff between moles and osmoles. Osmoles take into narrative a solute dissociating into solution. So if you had 1 mole of NaCl dissolved in 1 L of water, you would own 1 mole of NaCl/L, BUT 2 osmoles/L of NaCl, because NaCl dissociates into 2 ions in solution: Na+ ions and Cl- ions.
If the ECF had a 300 mM solution of NaCl (by way of IV infusion), that manner it would have a 2*300 = 600 mOsm solution of NaCl too, right? The normal body concentration of NaCl is about 300 mOsm, so this 600 mOsm solution would be hyperosmotic relative to the cell.
I reckon the 600 mOsm solution of NaCl would be hypertonic (relative to the cell), because a 600 mOsm solution of NaCl has non-penetrating solutes (NaCl is considered to be a non-penetrating solute). A cell's concentration of non-penetrating NaCl is 300 mOsm, which is less than the nonpenetrating solute concentration of the ECF (600 mOsm). Since the ECF is hypertonic, it would cause the cell to shrink (because the cell have a greater water concentration than the ECF). A net flow of water would walk from the cell to the ECF (body fluid).
Osmolarity would decrease in the ECF (because it is gaining a larger volume) and osmolarity would increase surrounded by the cell (b/c its volume decreases).
b.) Normally, cells have a 0.9% solution of saline (NaCl).
If you have a 1.8% saline solution surrounded by the ECF, that means the ECF is hyperosmotic relative to the cell. The ECF solution is hypertonic again. A net flow of water from the cell to the ECF would ensue. Osmolarity would decrease in the ECF and increase in the cell.
c) Now, you enjoy less NaCl in the ECF than in the cell (cells hold about a 0.9% solution of NaCl). Normal cells also have a 5% concentration of dextrose (a thorough solute). The ECF would then be hypoosmotic and hypotonic. A net flow of water would dance from the ECF to the cell, causing the cell to burst. Osmolarity would increase in the ECF and decrease contained by the cell.
Does all of this make sense? I know I typed a lot of information, so if something is confusing a moment ago send me an email and I'll help clarify everything. Source(s): UW pharmacy student
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i obligation a little help here...whats diff btwn osmolarity and tonicity?
a. 300 mM NaCl
b. 1.8% saline solution
c. 0.45% NaCl + 5% dextrose in river (D5W)
Answers:
I'll first say the diff between tonicity and osmolarity.
Tonicity is the concentration of ONLY non-penetrating solutes in a given solution.
Osmolarity refers to the concentration of BOTH non-penetrating and penetrating solutes contained by a solution.
I'll give an example to help clarify this:
Say you had a cell that (in the intracellular fluid) have 300 mOsm of NON-penetrating solute (such as NaCl) and 20 mOsm of penetrating solute (such as urea).
Let's also say that the extracellular fluid has one and only a 300 mOsm solution of non-penetrating solutes, and had an equal volume with the cell. In this case, the cell would be hyperosmotic relative to the ECF (because it contains 320 mOsm of solutes, compared to 300 mOsm contained within the ECF).
BUT, the cell would be isotonic with the ECF (because both have the same concentration of non-penetrating solutes). So, the cell would neither shrink nor swell because it is isotonic near the ECF. Only tonicity affects the diffusion of water from one compartment to another (which causes it to shrink or swell depending on the situation).
NOW let's say the ECF individual has 200 mOsm of non-penetrating solutes (and still had an equal volume as the cell). In this case, the cell would still be hyperosmotic, but presently it would also be hypertonic relative to the ECF solution. From the perspective of the ECF, the ECF would be hypotonic relative to the cell (because the ECF has a less concentration of NON-penetrating solutes than the cell). Because the ECF has smaller quantity solutes, but still the same volume, that means it has a greater concentration of marine than the ICF, and by way of osmosis, a net flow of water from the ECF to the cell would materialize (causing the cell to swell). Does that help? If you need more explanation, drop me an email.
Now, let's answer your questions. I'm assuming "body fluid compartment" refers to the ECF. Assume the cell in general has a 300 mOsm solution of NaCl.
a.) Let me first say that there's a diff between moles and osmoles. Osmoles take into narrative a solute dissociating into solution. So if you had 1 mole of NaCl dissolved in 1 L of water, you would own 1 mole of NaCl/L, BUT 2 osmoles/L of NaCl, because NaCl dissociates into 2 ions in solution: Na+ ions and Cl- ions.
If the ECF had a 300 mM solution of NaCl (by way of IV infusion), that manner it would have a 2*300 = 600 mOsm solution of NaCl too, right? The normal body concentration of NaCl is about 300 mOsm, so this 600 mOsm solution would be hyperosmotic relative to the cell.
I reckon the 600 mOsm solution of NaCl would be hypertonic (relative to the cell), because a 600 mOsm solution of NaCl has non-penetrating solutes (NaCl is considered to be a non-penetrating solute). A cell's concentration of non-penetrating NaCl is 300 mOsm, which is less than the nonpenetrating solute concentration of the ECF (600 mOsm). Since the ECF is hypertonic, it would cause the cell to shrink (because the cell have a greater water concentration than the ECF). A net flow of water would walk from the cell to the ECF (body fluid).
Osmolarity would decrease in the ECF (because it is gaining a larger volume) and osmolarity would increase surrounded by the cell (b/c its volume decreases).
b.) Normally, cells have a 0.9% solution of saline (NaCl).
If you have a 1.8% saline solution surrounded by the ECF, that means the ECF is hyperosmotic relative to the cell. The ECF solution is hypertonic again. A net flow of water from the cell to the ECF would ensue. Osmolarity would decrease in the ECF and increase in the cell.
c) Now, you enjoy less NaCl in the ECF than in the cell (cells hold about a 0.9% solution of NaCl). Normal cells also have a 5% concentration of dextrose (a thorough solute). The ECF would then be hypoosmotic and hypotonic. A net flow of water would dance from the ECF to the cell, causing the cell to burst. Osmolarity would increase in the ECF and decrease contained by the cell.
Does all of this make sense? I know I typed a lot of information, so if something is confusing a moment ago send me an email and I'll help clarify everything. Source(s): UW pharmacy student
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