I first want to deal with the subject of water, because after all we are 60% water. I don't know how many of you who want to go into fields like nursing know just how important it is. for nurses to track water balance in a patient. You may or may not know that every time fluids are administered to a patient, especially by IV drip, so they have to, the nurse writes down what the. volume of fluid was that was administered to the patient.
Sometimes nurses are asked to measure the volume of urine that is excreted by the patient. There's a measuring cup that's in the toilet and when the patient goes to urinate it collects it in the cup and the nurse is supposed to measure and record right down how much fluid came out before they flush it down the toilet. And on the... Obviously, it's very important in terms of water balance. You can't, there has to be some relationship between the amount of water going into the patient and the amount of water coming out of the patient.
If there's a lot more water coming out than going in, they're going to become dehydrated. On the other hand, if there's more water going in than coming out, they're going to burst from too much water going in. So the water balance is a very, very important subject. We can estimate the TB... the total amount of water in somebody's body using this little simple formula that the total body water is 60% of the body weight expressed in kilograms.
Now, we're going to explain shortly why you have to use the body weight in kilograms and not pounds. But before we do, since this formula says we have to know, if you wanted to calculate your own amount of water in your body, your body, you would multiply 60% times your body weight in kilograms. The problem is most of us don't have scales at home that measure in kilograms, they measure in pounds.
So we have to know how to convert from pounds to kilograms. You learn how to do this in a chemistry course. But we're going to remind you, if you've had chemistry and if you haven't, you'll learn it now.
The method we use, that we're going to use commonly in this class is kind of this cancel. of units. If, let's just imagine somebody weighed 154 pounds.
Alright, so they weigh 154 pounds. Right? You can figure out how much you, you know, weigh. Let's convert that to kilograms.
Now what we do is when we want to convert from one unit to another, we start out with this is what's given and the unit we want to get rid of we put in the denominator of a fraction. This is a fraction and the top part's called the numerator and the bottom part's called the denominator. So we put pounds on the denominator, that way the pound units will cancel out.
And we put in the numerator the new unit we want to convert to, and that's kilograms. We want to go from pounds to kilograms. Now, we're all set to go, except we just need to say, state, some true, make some true relationship between pounds and kilograms. Those of you who've had chemistry, I'm sure learned that one kilogram is about 2.2, really 2.24. pounds.
So you should know that. If you didn't know it before, you know it now. So on a test, expect a question.
And it's only their study guide questions like this. Expect a question on the test where you have to convert from pounds to kilograms. So now let's multiply this out. 154 times 1 is 154. Divide it by 2.2. The pound units cancel out and it's kilograms.
Now this is the point where everybody usually pulls out a calculator. Right? And over the years I've seen students use calculators. Unfortunately, this is commonly what it looks like to me. I'll see a student basically trying to calculate this, and it looks like this.
I'm looking, I don't know what the hell they're doing. Alright, I have no idea, they're punching in so many numbers, I have no idea what they're doing. Before you can use that calculator, I strongly urge you to estimate what the number should be.
If we were dividing 2 into 150, what's 2 into 150? 75. You should be able to know that. The answer has to be about 75. Alright, now that you know it's about 75, now you can take your calculator.
2.2 into 154 comes out 70. We knew the answer, we estimated it was going to be about 75. But it sure isn't 7 or... seven hundred and that's what I will sometimes see students give me an answer of seven or seven hundred now what they'll commonly say is for a way to say professor Fink don't I get partial credit I mean the decimal point was in the wrong place And my response is, you killed your patient. Your patient is dead. The most important part of any number is the decimal point.
That's what's important. I would rather have you estimate 2 into 150 is 75, than tell me the right answer is 700 or 7. You're not going to kill anybody if the right answer is 70 or you wrote 75. You can kill somebody if you wrote 7 or 700. Thank you. All right, so what we're saying is somebody weighs 154 pounds, weighs equivalent to 70 kilograms.
All right, so now let's calculate the amount of water in that person's body. 60% times 70 kilograms, because 60% of the body weight is water. Now, to convert from 60% to a decimal, you move the decimal 0.2 places to the left.
So 60% becomes 0.6. Think about this. Isn't 50%... percent the same as.5. Alright, so 50 percent is the same as.5, 60 percent is.6.
So.6 times 70. Alright, now.5, half of 70 would be 35. We know the right answer has to be about 35..6 times 70 is 42. But it sure isn't 4.2 or 420. The decimal point is the most important thing about these numbers. Because then you're off to. by factors of 10 or 100 or 1000 or you've only given a tenth or a hundredth or a thousand. So again I'd rather have you estimate and be off a little bit than have that decimal point in the wrong place. Alright so what we're saying here is that if somebody weighs 70 kilograms, 42 of their 70 kilograms in their body weight is water.
Now why did the body weight have to be expressed in kilograms? Why could we have used pounds? And here's why. When they designed the metric system, they did something very clever. One liter of fluid weighs one kilogram.
That's the way the system was designed. One liter of fluid. One liter of water or fluid in general weighs one kilogram. There is no one-to-one relationship between a quart of water weighing one pound.
For sure it doesn't. Okay? So because there's this one-to-one relationship, in the metric system. That means that when we come back here, if somebody, if the fluid in their body weighs 42 kilograms, which we calculated using their body weight, then they have about 42 liters of fluid in their body.
So that's why we use it that way. So there's a one-to-one relationship. All right, now if we look on the next page, on page C2. So this is showing, this is representing the fluid in our body by a rectangle. Okay, so this represents the fluid in our body.
And you'll notice right up here at the top, it even points out. It says the total body water is 60% of the body weight. I added kilograms. And it says the normal volume is 42 liters.
Wait a second. Hold on. Wait a second. When I gave the example on page C1, we calculated 42 liters.
on the assumption that somebody weighed 70 kilograms or 154 pounds. They're saying on that diagram that there's normally 42 liters of water in somebody's body. In other words, I did not...
choose 70 kilograms or 154 pounds. That number is the reference person. So in fact if you look on this diagram, let's read what it says right here in small print.
bottom. Fluid compartments of the body. Volumes are for the average 70 kilogram man.
Now when you took anatomy, you learned in an anatomy class that there was an anatomic position. Remember that? A reference position.
So when you're explaining you know where your thumbs are compared to your little fingers. You know, where they are depends upon which position your hand is turned. But we know the reference or anatomic position is with the hands turned like this, palms forward.
Well, in physiology and medicine, there is a reference. reference person and that reference person we always make reference to is a young adult man weighing 70 kilograms. So now you know, when I use that example of 154 pounds or 70 that I didn't just make that up that is our reference person so anytime we learn what a normal value is like the amount of water in the body it assumes the person is a young adult man weighing 70 kilograms that is our reference person this is also used in drugs in pharmacology the reference person is a young adult man weighing 70 kilograms so when you read what the dose is That dose is for a young adult male weighing 70 kilograms. That's not the dose of the drug you would give to a child. It's not the dose you would give to an 80-year-old elderly person.
It's not the dose you would give to a small petite woman. So that is the dose that is given to our reference person. Now, the reason why they came up with this 70-kilogram young adult guy is when they were... learning what normal values were, who did they originally obtain this data from?
So it's not like they had a lot of volunteers in the 1940s and 1950s. It's not like everybody was volunteering. Why don't you go and analyze me?
So they got what was normal from two sources. They got them from young, younger, they got them from new army recruits. Because when you join the army or you're drafted. they give you a complete physical exam.
And so they assume they're dealing with relatively healthy people, and they basically determine that the normal values for almost all these things in these approximately 154 pounds, 70 kilogram young adult guys, that's how they were able to find out what's normal. What's the normal blood pressure? What's the normal heart rate? What's the normal body temperature? What's the normal everything?
The second group they got the data from was first year medical students. And in the ninth year, they got the data 1940s and 1950s, most first-year medical students were young adult guys weighing about 70 kilograms. Now, of course, today, whether we look at Army recruits or first-year medical students, you know, there's plenty of women.
So we know what normal values are for women today, as well as guys. But nevertheless, they still, in all the books, in the physiology and medical books, all books, anytime they are telling you what's normal, it is for a young adult. adult guy.
Now you might say, well why don't they tell us what it is for a young adult woman? Because the values are different. Let me show you how they're different. The normal lung volume of a guy, young adult guy, normal lung volume is six liters. The normal lung volume of women, young adult women, is about four liters.
That's a difference of two liters. Now you might say, well okay, so I'll just take the average. Well the average of the of six and four is five.
But if you memorize five leaders, that's not normal for either one. If you've memorized five as the normal, then that's really less than normal for what guys should be and more than normal for women. What you really need to do is memorize both sets of values. Nobody wants to memorize two sets of values.
All right? It's hard enough to remember one set of values. So even though we do know all this information now, we still traditionally. traditionally in all the books tell you the normal value for young adult guys.
And really there's more than just two sets of values because the values change our entire life. The normal resting heart rate for guys in their 20s is about 70 to 75 beats a minute. Does anybody have any idea what the normal heart rate is of an infant?
About 120 beats a minute. So, you know, don't think that when you memorize and we learn the normal heart rate is 75, that's not what the normal heart rate is of an infant. And it changes your whole life. It becomes, changes everything. Blood pressure.
heart rate, lung volumes, everything changes as we go from infancy to childhood to adolescence, our teen years, to young adults, to middle-aged adults, to elderly people. In women, it changes during pregnancy. The normal values... Her heart rate and blood pressure change between the first trimester, the second trimester, and the third trimester of pregnancy. So it's not just one value or two values or three values, it's an infinite number of values.
So nobody can memorize them all. So what we do is we learn one set of values and then when you're dealing with an 80 year old woman, you're going to look it up what's normal. Now it's all in the computer.
If you're dealing with an 11 year old boy, you're going to find... find out. You'll use the computer system to tell you what the normal values would be for an 11 year old boy. So, and all of these are affected not only by the age of the person, by their gender, male or female, by their size.
Obviously somebody who, even a young adult guy, there's a difference between a guy who weighs 120 pounds who's 5 foot 4 and somebody who's 6 foot 7, 7 foot 2 and weighing 320 pounds. These are very different guys. They're very different women in terms of their size.
All of these also affect our drug dosing. So drug dosing, there are various formulas that are used to adjust the drug dosage for the person, your patient, who your patient is. So we do not treat, ideally you don't treat everybody the same way. You give them the right treatment for who they are.
And it's based on gender, based on age. based on height, based on weight, and so on. And there are various formulas for adjusting all this stuff. So I'll just point this out. But everything we're going to learn in this class is for young adult guys.
Because we've got to start somewhere. All right, now, what this diagram indicates is this is the total amount of water in the body. Now, this indicates that two-thirds, approximately two-thirds of the TBW, the total body water, is inside cells, intracellular fluid. The remaining one-third, one-third of the...
of total body water is extracellular fluid outside the cells. So we can actually estimate, once we know the total body water, we can estimate the intracellular fluid volume or the extracellular fluid volume. Let's go back to the previous page, page C1.
At the bottom of page C1, So let's estimate the amount of fluid that's inside the person's cells. It is about two, ICF is approximately two-thirds times the total body water. In our reference person who weighs 70 kilos, he had 42 liters of water in his body. 2 thirds times 42 is 84 divided by 3 or 28 liters.
So of the 42 liters in his body, 28, 2 thirds of it is inside his cells. I would strongly recommend you try calculating these same things for yourself. Alright, so you, because I'm going to give you questions like that on the test. Alright, this was just for a reference person. Now, on page C3.
The extracellular fluid is about one-third of the total body water. So, for a reference person, if they have 42 liters of water in their body, one-third times 42 is 42 divided by 3, or 14 liters of fluid. is extracellular, outside their cells. Now, there are different types of extracellular fluids. There are different types of extracellular fluids.
But let's go back here to the diagram. And we see that there are different types of extracellular fluids. There's something called tissue fluid, something called transcellular fluids, and something called blood plasma. These are three different types of extracellular fluids.
Let's try to convey what this means. Let's look at the bottom picture. The bottom picture is just showing a tissue from the body. This represents any part of your body.
This could be liver tissue. This could be pig. Pancreatic tissue, this could be kidney tissue, this could be muscle tissue, it could be any tissue in the body. So any tissue is made up of tissue cells.
These are the cells. Maybe they're liver cells, maybe they're pancreas cells, maybe they're thyroid cells, maybe they're stomach cells, maybe they're muscle cells, doesn't matter. Inside the cells is intracellular fluid, ICF.
But surrounding the cells is what we call... tissue fluid which is a type of extracellular fluid. So what is tissue fluid?
It is the fluid surrounding tissue cells. Haven't we learned that all living cells must be surrounded by fluid? You'd say, when did you tell us this?
Go back to page B1. Page B1. You drew a picture of a cell, and that's where you wrote down cytoplasm is 80% water and all living cells are surrounded by extracellular fluid, called tissue fluid. Page B1.
Now, we've talked about intracellular fluid inside the cells and tissue fluid, which is an extracellular, extracellular means outside the cells. In close proximity to all tissues, tissue cells are blood vessels. Here's a capillary. Here's a capillary.
Capillaries we know are the way that we deliver nutrients to the cells and carry away waste products away from the cells. What's inside blood vessels? Blood.
Blood. Blood. All right.
What is blood? Whole blood is made up of two things. Blood cells and fluid called plasma. That's what's in blood vessels.
Blood cells and plasma. All right. Now, most of the blood cells are red blood cells.
We have far, far fewer white blood cells than red blood cells. We measure red blood cell counts in the millions, and we measure white blood cells in the thousands. Now obviously inside a red blood cell is intracellular fluid, right? That's inside the cell. The surrounding the blood cells is extracellular fluid, fluid out the cells but we give a special name to the extracellular fluid around blood cells compared to the extracellular fluid around regular tissue cells surrounding tissue cells we call a tissue fluid but surrounding blood cells we call it plasma plasma is the extracellular fluid surrounding blood cells and it is confined to the blood vessels So, in the diagram above, so far we've seen the distinction between what we call tissue fluid, which is the extracellular fluid around most cells of the body, and blood plasma, which is the name for the extracellular fluid around blood cells.
Now, there's one more category of extracellular fluid. It's called transcellular fluids. What are transcellular fluids?
Well, first of all, let's look on page C3. On C3, so you'll notice on C3 we listed extracellular fluids, and then here's these three that we've been mentioning, tissue fluid, transcellular fluids, and blood plasma. Now, tissue fluid is also known as interstitial fluid or intercellular fluid. In fact, most nursing books call tissue fluid interstitial fluid. That's the term used in all nursing books.
Why is it? it called that interstitial means between the spaces between the spaces of the cells there's this tissue fluid interstitial fluid it's also called intercellular inter means between between the cells so tissue fluid is the fluid between tissue cells between the spaces of the cells make sure you know that all three of those terms mean the same thing In the future, your clinical courses are going to use the term interstitial fluid. Now, what are transcellular fluids?
Transcellular fluids are also extracellular. They are outside the cells, but they are located in specific anatomic areas. They are located in specific anatomic areas. In specific anatomic areas, you might say, what does that mean? All right, let me give you a really easy example to start with.
Let's look at the last of these transcellular fluids. Intraocular fluid. You'd say, what's that? That's the fluid.
in your eyeball. Some of you in anatomy might have heard the terms aqueous humor and vitreous humor. Whether you heard those terms or not, we will be learning them in this class, but those are the fluids that are in your eyeball.
There are outside cells. That's not the fluid inside cells, but it is contained in your eyeball. It is an extracellular fluid localized anatomically in your eyeball.
Other examples of extracellular fluids located in specific anatomic areas is cerebrospinal fluid. You may have heard of that, whether you have or not, we'll be reviewing it another time. That's the fluid on the outside of your brain and spinal cord.
There's about 100 milliliters of cerebrospinal fluid surrounding your brain and spinal cord. cord. It's actually made within your brain, but it circulates on the outside of your brain and spinal cord. It is outside the cells, and it is confined within your skull and your vertebral column.
It's contained around your brain and spinal cord. Another example is, you all know this from anatomy, synovial fluid. You learn about synovial joints, such as the knee joint.
And so you know that there is this kind of slippery fluid that is... found within a synovial or movable joint. And sometimes there can be a buildup. If there's injury or trauma to the knee, there's a buildup of that synovial fluid.
That is a transcellular fluid. It is an extracellular fluid that is localized in a specific anatomic place, anatomic location. Other examples are slippery serous fluids. I call them slippery fluids.
I call them slippery fluids. For example, peritoneal fluid. Peritoneal fluid is secreted by peritoneal membranes in your abdomen. And so this is a fluid in your abdominal cavity.
It is confined and located in the abdominal cavity. It's called peritoneal fluid. Sometimes there may be a buildup of excessive amounts of this peritoneal fluid.
Does anybody know what that's called? It's actually... actually written right here.
It's called ascites. Have you ever heard that term? Ascites is the name for a buildup of abdominal or peritoneal fluid.
Ascites, A-S-C-I-T-E-S. They're a plural fluid. What's plural fluid? Where's that located? Anybody know?
Lungs. That's in the chest. That's around the lungs. So there is fluid around the lungs confined within the chest cavity. It's actually produced by plural membranes.
And so you can have a buildup of plural fluid. All of these are examples of extracellular fluids that are localized in specific anatomic areas. All right? They're confined. They're confined.
Now, where we're going with this is you can have problems. You can either have an excess or deficiency of fluids in any of these different compartments or places. You can have a buildup of synovial fluid or intraocular fluid or cerebrospinal fluid.
Question? No, ascites. Can you please explain?
Ascites is a buildup. of peritoneal fluid, fluid in the abdomen. So does anybody know what they call the condition with the buildup of cerebrospinal fluid? Spinal fluid? No, hydrocephaly.
which literally means hydro water, cephalic brain, water in the brain. You've heard of buildup of synovial fluid after injury to a knee, where it has to be drained. Anybody know what it's called when you have an increased buildup of fluid and pressure in the eye?
It's called glaucoma. Glaucoma. All right?
So you can have problems in all these different fluid compartments as far as what's going on. All right. These are called transcellular fluids. And then we have blood plasma.
Blood plasma we've seen. is the name for this extracellular fluid surrounding blood cells that circulates in the blood vessels of our body. Now, just going back to our diagram here on the previous page, I drew some arrows in this diagram.
To indicate that fluid can move from one compartment to another. So I've got arrows going back and forth here, and back and forth here, and back and forth here, and back and forth here, and back and forth here. You might...
say I don't get that what do you mean okay let's help you understand this better by showing you something more anatomic this is kind of more like anatomy and the other above is more physiology all right so looking at the anatomy if we started to have increased amounts of plasma fluid moving out of the bloodstream into the area around the cells That would increase the amount of tissue fluid. That's commonly known just as edema or swelling. So edema or swelling is when we get increased flow or movement of fluid out of the bloodstream, the plasma, into the tissue fluid. And we get this swelling. And that can occur anywhere.
anywhere in the body. You can have edema or swelling in your feet. Right?
Anybody ever have edema or swelling in your feet? You can have edema or swelling in any part of your body. An arm, anywhere.
An organ. We could have the fluid moving in the reverse direction. We can have fluid moving out of the cells into the tissue fluid and from the tissue fluid moving into the bloodstream.
So the cells would start to shrivel up and there's a decrease in tissue fluid. as the fluid moves into the bloodstream. That's actually what happens with dehydration.
With dehydration, when somebody's dehydrated, the fluid in the cells and surrounding the cells is decreasing. So the cells are all dehydrated. Alright, so this fluid, that's what we indicated here, this fluid can move. Fluid can move out of the bloodstream, into the tissue fluid, and then into the cells, or vice versa.
It can move from the cells, into the tissue fluid, and into the bloodstream. It can move from the bloodstream into the transcellular fluid compartments. That's what happens commonly with trauma or injury.
Trauma is injury. When you injure the knee, fluid from the bloodstream starts to flow into the... the knee joint, this increasing synovial fluid in the knee joint. When you have injury to the head, trauma or injury to the head causes an increased movement of fluid from the blood stream into the cerebrospinal fluid and you get swelling, increased fluids build up around the brain and that's called cerebral edema, okay, swelling in the brain. So anytime typically there's injury or trauma, it does cause...
cause changes in the flow of fluid in the body. I think you're getting a sense physiology is very different than anatomy. But it's really clinically relevant to how the whole thing works.
Now we wrote here on page C3, on page C3, how do you estimate the total blood volume in the body? Now this is another thing you should know how to estimate, total blood volume. You'd say, why? Well look, if somebody needs blood, shouldn't you know about how much blood they should normally have in their body?
Or do you just keep pumping it in until... they burst. In other words, we need to estimate what's their normal blood volume and we're going to give them replacement volume of fluid or blood.
We don't just keep pumping it in there no matter how big of a person. they are. So the blood volume, like most things in our body, is proportionate to our size, to our weight.
And our TBV, or total blood volume, don't confuse that with total body water, TBW, the total blood volume is approximately 8% of our body weight expressed in kilograms. Now where did we get this number 8%? So I wrote up here that since whole blood is made up of blood, so I wrote down here that since whole blood is made up of blood, so I wrote cells, mostly red blood cells, and plasma. The blood cells make up about 3% of our body weight, expressed in kilograms, and our blood plasma makes up about 5% of our body weight, expressed in kilograms. So since whole blood is both blood cells and plasma, what's 3 plus 5?
8%. So 8% of our body weight is our blood volume, approximately. So, now, to convert from percent to percent, we're going to convert from percent to percent.
So, we're going to to decimal, you move the decimal point two places to the left. So 8% becomes.08. You'd say I don't get that. Okay, well think about this.
If it was 10%, wouldn't 10% be.1, 1 tenth, right,.1? So if 10% becomes.1, 8%, which is less than 10%, is.08. It's got to be less than.1,.08. If you think this... through.
If you're kind of thinking you're not going to make mistakes. If you don't think and assume your calculator knows everything you will make mistakes because calculators are no smarter than when we empower them and just punch numbers in and we're not thinking about what's going in. Anyhow, so let's estimate the answer. Before we take our calculator and multiply 0.08 times 70, that's our reference person who weighs 70 kilograms. If the blood...
volume was 10. Ten percent or 0.1 of 70, 0.1 of 70 would be 7. So we know the right answer has to be about 7. Now we can use our calculator, multiply 0.08 times 70 and get 5.6. But if you write.56 or 56, you're not even thinking. Because we estimated that it had to be around 7. So it couldn't possibly be.56 or 56. I only mention this because...
because these are the kinds of answers I've seen. All right, so if this means that if we weigh 70 kilograms, 5.6 kilograms of our body weight is our blood, our whole blood. And since there's approximately a one-to-one relationship between weight and volume in the metric system, there's about 5.6 liters of blood in our body.
Most adults have somewhere between 5 to 6 liters of blood. 5 to 6 liters of blood. Look, obviously... it's proportional to your body weight.
If you're a child, obviously you weigh less and your blood volume is smaller. If you're a 6 foot 5, 350 pound halfback for the Green Bay Packers, then your blood volume is significantly bigger. Now, I'm sure some of you have donated blood before.
And when you donate blood, they typically withdraw one pound of blood. They call it a unit of blood, one pint or 500 milliliters, half a liter of blood. So they call it a pint, a pint of blood.
So when you donated blood, you gave that pint, that unit of blood, I mean so what did they take from you? Did you give them half your blood volume? No, you didn't have to make a.
Okay, so let's approximate what you gave. 5.6 liters in our reference band is about 5.6 quarts. You may remember from chemistry and biology that one... One quart, one liter is 1.06 quarts. So a liter is just ever so slightly more than a quart.
You wouldn't think of them as almost the same. So if there's 5.6 liters of blood in your body, there's 5.6 quarts of blood. But let's just round it off to make the numbers really simple.
Let's just say five. Okay, so you have five quarts of blood. Really, you got more than that, but let's say five quarts. Here's an English conversion. One quart is two pints.
Most people don't know that. So if you're buying milk at the market, you can either get one quart or two pints. They mean the same thing.
So if one quart is two pints, five quarts is two times five, ten pints. So you've got about 10 or 12 pints of blood in your body. So when you donate one pint, you are giving less than one-tenth of your blood volume.
Because you really had more than 10 pints. You were giving about 10% or really less. They don't want to, they always want to take one pint.
They feel that if they take less than a pint, it's not even worth doing. They don't want to take a fraction of a pint. And so because they do not want to take more than one pint, take more than one tenth of your blood volume, that's why some of you know that a person who weighs less than a hundred pounds doesn't give blood.
Anybody know that? If you weigh less than a hundred pounds they won't take your blood. Because since your blood volume is proportional to your body weight, if they take a pint of blood from somebody weighing less than a hundred pounds they'd be taking more than one tenth of their blood volume and they don't want to do that. So that's why they have that rule. If you're very petite, to less than 100 pounds, they won't take your blood.
In other words, when you donate blood, you've given 10% or less. If you gave twice that or lost that, twice that volume, you lost a liter of blood, a quart of blood, then you need medical attention. On page C5.
So this says distribution of electrolytes. Now electrolytes, you'll recall, are electrically charged chemicals. Chemicals with an electric charge, also known as inorganic ions or minerals.
Now this was a little chart and I kind of turned this into a cell. Alright, here's a cell, here's a few of these. These are the major electrolytes in the ICF, the intracellular fluid of the cytoplasm. These are the major electrolytes, electrically charged chemicals in the ECF, the extracellular fluid, the fluid on the outside of the cells. There are major differences.
We see that among the univalent cations... You'd say, what is that? A cation has a T which looks like a plus sign. Univalent means plus one. So among the plus one chemicals, most of the plus one or univalent ions that are inside the cell are potassium.
But most of the univalent cations in the outside of the cell are sodium. Now, I'm not yet explaining what that means or what that's for. That's what we're going to be learning. But most of the potassium in our body is in our cells, in the intracellular fluid.
Most of the sodium in our body is in the extracellular fluid. Among the divalent cations plus two charged ions or electrolytes, the major divalent cation on the inside of the cell is magnesium. The major...
the major divalent cation in the extracellular fluid is calcium. Again, we haven't explained what that's for, but we're simply pointing out there's a difference in the chemical composition of the fluid inside cells versus the fluid outside cells. Of the negative charge anions, anions have a negative charge, the major anions in the extracellular fluid are negative charge chloride and bicarbonate, bicarbonate. Those are the major anions in the extracellular fluid.
Notice that what we're saying, in the extracellular fluid, there's a lot of sodium and chloride. In other words, salt in the extracellular fluid. And there's sodium bicarbonate. Sodium bicarbonate.
Now, anybody who's had biology and or chemistry knows what sodium bicarbonate is or bicarbonate. It is a buffer. Buffers reduce acidity or alkalinity.
So the major buffer that regulates, that's involved in maintaining our pH is sodium bicarbonate or bicarbonate. That's the buffer in the extracellular fluid. The major anions... or negative charge chemicals inside cells are negatively polarized phosphate because there's a lot of phosphate in cells for nucleotides and phospholipids and adenosine triphosphate, adenosine diphosphate.
and a lot of negatively polarized proteins. Now most proteins have a slight negative polarity. Amino acids, there are some amino acids that have a positive polarity, some have a negative polarity, and overall most proteins have more amino acids with a negative polarity than positive polarity, so overall they have a negative polarity. We'll talk more about that later in the course when we talk about electrophoresis, where proteins move towards a positive pole in an electrophoretic device.
All right, so most proteins have an overall negative polarity. Now, we're going to... to be, right now this is all you need to know about the differences in the electrolytes between what's inside cells and outside cells. We're going to be quantifying this.
Let's show you what I mean. Look on the previous page at the top. C4.
All right, on page C4, at the top, these are the real numbers that we will be learning, at least some of these. First of all, what this shows, here it lists the various electrolytes, positive charged cations, negative charged anions, and it gives their actual concentrations in the units milliequivalents per liter, in the intracellular fluid, in the tissue fluid, and in the blood plasma. All right, but you'll notice that inside cells, there's just a low amount of sodium, but there's a significantly high amount of potassium.
There's a low amount of calcium, but a high amount of, relatively speaking, magnesium. That's what I summarized on the next page. You'll notice that among the negative charges, there's a significant amount of phosphate, and there's also quite a bit of protein, which has a negative polarity. Now, tissue fluid and blood...
and blood plasma are both extracellular fluids, right? These are two different extracellular fluid compartments. What we notice looking at the numbers is that by and large, they're pretty similar, almost identical, almost identical.
Notice high amounts of sodium in both. Both tissue fluid and blood plasma, extracellular fluids, in both cases low in potassium. You'll notice that in both cases, high in chloride, but low in, say, phosphate. There is one major difference in the electrolytes of tissue fluid and blood plasma.
And that big difference is protein. You'll notice there's no... zero protein in the tissue fluid but there is a sizable amount of protein in blood plasma now in fact let's go back to c2 back on page c2 On C2, this diagram is shaded in to reflect protein levels.
You'd say, what do you mean? You'll notice right here on the intracellular fluid, it's shaded in darkly. represent there's a high amount of protein inside cells.
After all, inside cells are where proteins are manufactured, right? Proteins are synthesized inside cells. So whether there's a lot of protein in cytoplasm, it's mostly water.
water protein. Notice it's clear in tissue fluid and transcellular fluid to represent the fact that there is normally zero protein in tissue fluid and zero protein in transcellular fluids, such as cerebrospinal fluid, such as peritoneal fluid, zero protein. But you'll notice for blood plasma there's dots to represent proteins, not as much protein as inside.
inside the cell where it's shaded darkly, but there is protein in plasma. There was no protein in tissue fluid or transcellular fluids. These are called plasma proteins. Where did they come from? They are mostly secreted by your liver.
Your liver is the major source of these plasma proteins. These plasma proteins include albulin. They include the blood clotting proteins. They include many, many other proteins circulating in our blood.
They are produced largely by our liver. You'd say should we know that? Yes, you should. This is why we're going to see in the future that when somebody has liver disease, their plasma protein levels drop.
Because these proteins are largely made by their liver.