Hey everyone, it's Sarah with RegisteredNurseAriene.com and in this video I'm going to be talking about body fluid compartments and osmosis. So let's get started. Now the average adult body is made up of about 60 to 70 percent of water. So that is a lot of fluid within our body and this fluid has to be stored somewhere and there are two main compartments that stores this fluid that I want you to remember. The first compartment is known as the intracellular compartment and this is the fluid that's found within the cell.
And intra means within. So remember, this is the fluid inside of our cell, as you can see here. Then we have the extracellular compartment.
And this is the fluid found outside of that cell. And extra means beyond or outside. So we're talking about that fluid that is surrounding the cell.
And it is made up of the intravascular fluid, which you can see here. This is also referred to as the plasma. Then we have the interstitial fluid, which you can see here in blue and it's just hanging out around our cells.
And then we have the transceiver fluid. fluid. So now let's take a closer look at these body fluid compartments with the first being the intracellular space.
So again, this was the fluid found inside of the cell and this space actually accounts for two-thirds of our body water. So most of our fluid is inside of our cells. And then there's the extracellular space, which again is that fluid outside of the cell. And it accounts for one third of our body water and it includes the fluid compartments such as the interstitial fluid compartment.
And the interstitial fluid compartment is the fluid that surrounds the outside of our cells. And this fluid plays a very vital role in helping be a medium for electrolytes and other substances to move to and from the cell to the plasma with the assistance of the capillaries. And the intravascular fluid compartment, which again is known as the plasma, is the fluid found inside the blood vessels, which contains so many important substances like electrolytes, blood cells, and so forth.
And then lastly, we have the transcellular fluid compartment. And this is actually the smallest compartment. And this is the fluid that is found within certain body cavities, like the spinal fluid, the fluid that surrounds our heart and lungs and the joints. Now it's important to note that these compartments are really all interconnected with their own amount of water and electrolytes and they will work together to help maintain a homeostatic environment in our body.
And how they do this is that they will shift water, electrolytes, and other nutrients around so we can keep that balanced environment. And they do this shifting through various processes in the body, with one of those processes being osmosis. Therefore in healthcare we can administer IV fluids, let's say to this intravascular compartment to help expand it if we need to, or shift fluids around these compartments via this process of osmosis to help us correct fluid imbalances or other problems that can occur within the intracellular and extracellular spaces.
So to help us understand how IV fluids do this, let's talk about osmosis. So osmosis is a process where water is going to move from a fluid of a higher water concentration to a fluid of a lower concentration. In other words, water is going to move from a fluid that has a low solute concentration to a fluid that has a higher solute concentration. And it does this passively. It doesn't need any energy or anything from the cell.
It actually does this on its own and it does it through a semi-permeable membrane which is only permeable to water molecules. So let's illustrate this process by looking at this drawing. Here we have our semi-permeable membrane which is only permeable to water.
And on one side of the membrane we have a lot of water molecules but we don't have a lot of solutes. And on the other side of the membrane we have not a lot of water molecules but a lot of solutes. So according to osmosis what's going to happen is that water is going to move from a higher concentration of water to a lower concentration water.
Or you can look at it this way. Water is going to move from the place where there's not a lot of solutes to a place that there are a lot of solutes. Now the big takeaway I want you to get from osmosis is that this process is highly influenced by a fluid solute concentration and depending on how concentrated that fluid is of the solutes will determine how osmosis is going to affect how water is going to shift from this extracellular space to the intracellular space or vice versa.
So what is a solute? A solute is a solid that has been dissolved in a liquid. And there's many different substances out there that can become a solute in a liquid solution.
with one being like sodium and chloride. So we can take sodium and chloride in their solid form, put them in a liquid. Whenever we do that, once they dissolve, they become an electrolyte, but there's still a solute in that fluid that we have.
Now we can take that and we can administer it to the patient in their intravascular system. Now depending on how much sodium and chloride we actually put in that fluid will determine how the process of osmosis is going to be affected in this extracellular and intracellular compartment. So that leads me to osmolarity. What is osmolarity?
Osmolarity is the amount of solutes within a specific fluid volume. So in other words, it's the total solute concentration per liter of solution. So depending on that IV fluids osmolarity will depend on how well osmosis is going to work within the body to shift fluid around these compartments. So we can term fluids as having a high osmolarity or a low osmolarity.
So whenever a fluid has a high osmolarity, we're saying it has a lot of solutes in that fluid. Whenever something has a lot of solutes in it, it has less water. On the flip side, if a fluid has a low osmolarity, it has a low amount of solutes in it, meaning it's going to have more water in it. And in healthcare, we can use osmolarity to our benefit to help treat patients who are sick and need fluids replaced based on what compartment we need to treat and shift fluids around.
We do this by administering various types of fluids that have different osmolarities or solute concentrations, which will move water in or out of these compartments. Okay, so that wraps up this video. And if you'd like to watch more videos in this series, you can access the link in the YouTube description below.