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Facilitated Diffusion In Your Body

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A very large percentage of our body is composed of fluids. The most basic and widely known fluid, water, is essential daily to maintain life. Other fluids in our body also broadly include serum, cerebrospinal fluid, albumin, and urine to name just a few. There is a very critical balance of these fluids that we must maintain for homeostasis; otherwise we could have an excess or deficit. There are two main fluid compartments within your body, being the intracellular and extracellular compartments. (McLaffert, Johnston, Hendry, & Farley, 2014) One-third of your body consists of the extracellular space which is found on the outside of cells. The compartment of extracellular can be further broken down into intravascular, or plasma and interstitial. …show more content…

The two types of diffusions are simple diffusion and facilitated diffusion. Simple diffusion is the free moving of lipid-soluble substances across the cell membrane using the concentration gradient. (McLafferty et al., 2014) Facilitated diffusion, however, is used for substances that need more assist. Membrane proteins are used for larger substances to diffuse through the membrane down the concentration gradient without the use of energy. Lastly for passive transports, is filtration. Filtration is when solutes and fluids move across compartments by filtration pressure. This pressure is within the compartments and consequently moves fluids and whatever is dissolved in them, out. (Trakola, 2015, p. 338) Hydrostatic pressure also plays a role in this transport and is defined by Pearson as “the pressure a fluid exerts within a closed system on the walls of its container” that it’s being held by. This pressure is also based on the standard that fluids move from an area of high pressure to lesser pressure. Previously discussed osmotic pressure, can on occasion have a relationship with hydrostatic pressure. When osmotic pressure is less than hydrostatic pressure in the vasculatures, fluid will leak out of blood vessels and can cause edema. In this scenario, the difference between the osmotic …show more content…

Tonicity is the osmolality of a solution or “the concentration of solutes” (Trakola, 2015, pg.337). Solutes can be either crystalloids, which are “salts that dissolve readily into true solutions”, or colloids that are “substances such as large protein molecules that do not readily dissolve into true solutions” (Trakola, 2015, p.337). Because of a solutions tonicity, it can be hypertonic, hypotonic, or isotonic. Hypertonic solutions cause cells to shrink from osmosis because it has “a higher concentration of electrolytes compared with body cells” (McLafferty et al., 2014). Hypotonic is the complete opposite so it makes the cells swell because it has “a low concentration of electrolytes compared with body cells” (McLafferty et al., 2014). Isotonic is equal in electrolyte concentration to the body so it acts as a fluid replacement. Listed in table 1 are different major IV fluids and what type of tonicity they’re categorized

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