Give the normal osmolarity of blood plasma. Which salt solution was closest to this value? which glucose ( detrose) solution was closest to this value?
The correct answer and explanation is:
The normal osmolarity of blood plasma is approximately 280-296 mOsm/L. This osmolarity is a measure of the total concentration of solute particles, including ions like sodium (Na+), chloride (Cl-), bicarbonate (HCO3-), and proteins that are dissolved in the plasma.
To answer the second part of the question:
- Salt solution: A 0.9% sodium chloride (NaCl) solution is closest to the osmolarity of blood plasma. This saline solution, often called normal saline, has an osmolarity of approximately 308 mOsm/L, which is slightly above the normal range of blood plasma. This concentration is used for intravenous fluid replacement because it is isotonic, meaning it has a similar osmolarity to that of blood plasma.
- Glucose (dextrose) solution: A 5% dextrose solution (D5W) is commonly used in medical settings and is also close to the osmolarity of blood plasma. The osmolarity of 5% dextrose is about 250 mOsm/L, which is lower than blood plasma’s normal osmolarity but still close to it. When dextrose is infused intravenously, the body metabolizes the glucose, which ultimately does not contribute to the osmolarity after it is absorbed.
It is important to note that solutions like normal saline and dextrose solutions are used for various clinical purposes, including rehydration, fluid replacement, and as carriers for medications. The choice of which solution to use depends on the clinical needs, such as maintaining proper hydration and electrolyte balance, which are crucial in patient care.
The osmolarity of blood plasma ensures that there is a balance of solute concentration between the plasma and the cells, preventing excessive fluid movement into or out of the cells, which can cause swelling (edema) or dehydration.