Final answer:
Crystalloids are indeed commonly used IV fluids, often isotonic like normal saline and lactated Ringer's to match body fluid's osmolarity. If red blood cells burst following an isotonic solution injection, the solution was actually hypotonic. Albumin, a plasma protein, helps maintain oncotic pressure but doesn't cross the capillary membranes via facilitated diffusion.
Step-by-step explanation:
Crystalloids are indeed commonly used intravenous (IV) fluids; the statement is true. These solutions, such as normal saline and lactated Ringer's solution, are isotonic with respect to body fluids, which is crucial. Isotonic solutions have an osmolarity close to that of body fluids (approximately 300 mOsm) thus they can replace lost fluids and maintain fluid balance without causing cells to shrink or swell. An isotonic saline solution should not cause red blood cells to burst if this occurs, as in the hypothetical case given it indicates that the solution was not truly isotonic but rather hypotonic, leading to the bursting of cells due to fluid intake.
Blood plasma proteins like albumin do not typically cross the capillary cell membrane via facilitated diffusion; they generally remain within blood vessels due to their size and contribute to osmotic balance by drawing water into the circulation maintaining oncotic pressure.