Cerebrospinal Fluid Versus Blood

[Nicholas Kang]

The function of Cerebrospinal fluid is the same as blood, why don`t our human body is created with brain filled with blood but not cerebrospinal fluid? Let say if blood can regulate its own concentration to act as shock absorber, thus fully replacing the function of cerebrospinal fluid.

Edited June 1, 2014 by Nicholas Kang

[Dislayer]

I would argue that the function of CSF and blood is not the same. Yes they both function to maintain homeostatic regulation but CSF is acellular with cell counts on average of 0-5 white blood cells and functions to cushion the brain and remove waste. Blood is full of cells and its main function is oxygen and nutrient delivery to the bodies cells. CSF is meant to be sterile because it comes in contact with the brain while blood (which is not sterile) is not in direct contact with the brain.

 

In order for blood to take the job of CSF you would need to remove all the cells, make it sterile, remove proteins and platellets. If you do all that you have CSF.

[Nicholas Kang]

Why don`t human revolution since thousands of years ago just directly have the ability to shift the blood specification to suit the brain environment but have to come up with CSF? Don`t you think that CSF is a waste if blood can just have the ability to maintain both blood and the CSF characteristics in different situations? Maybe blood can auto eliminate certain cells and can then be sterile and won`t harm the brain when in contact with the brain?

[Endy0816]

Contaminants can end up in the blood cells themselves or in the bloodstream. You don't exactly have a ready supply of replacement brain cells.

 

Evolution tries to find the least energy intensive option that gets the job done long enough for the next generation to provide a much needed reset. The filtering that goes on in the blood-brain barrier is a result of that.

Edited June 5, 2014 by Endy0816

[Dislayer]

Why don`t human revolution since thousands of years ago just directly have the ability to shift the blood specification to suit the brain environment but have to come up with CSF? Don`t you think that CSF is a waste if blood can just have the ability to maintain both blood and the CSF characteristics in different situations? Maybe blood can auto eliminate certain cells and can then be sterile and won`t harm the brain when in contact with the brain?

 

What you just described is CSF. If you take out the cells from blood, all the proteins and make it sterile you end up with something similar to CSF. That is probably how CSF evolved over time.

[Nicholas Kang]

I don`t mean how CSF had evolved over time but I mean why don`t blood evolve into CSF.

[Endy0816]

There would be too many issues. What exactly do you think of when you use the word blood?

[John Cuthber]

Just for the record, while I am, by all accounts, remarkably conceited, I would think very carefully before coming to the conclusion that I know how to solve a problem like brain nutrition and protection, better than a zillion years of evolution.

As I see it, among other advantages,the system of having two different fluids gives me a second line of defense, protecting my brain.

As woody allen said "my brain: that's my second favourite organ"

[Nicholas Kang]

Why do you need 2 fluids? What you need is one fluid with 2 functions (That is my idea). If you say defense line, I will rather say solid body components to CSF, like bones, hard skull or strong skin structure.

 

What do I exactly think of when I use the word blood? I think of I am getting Nobel Prize very soon. (I am just kidding but it might be true in the future). I think of nothing, actually. Why blood? Because I came across the components of brain during my First Aid lesson in my school, then an idea shook up my mind, why CSF and not blood? The mentor in the course first taught us the function of CSF, then I realized one point: The function of CSF and Blood is nearly the same. Thus, I asked my mentor this question. She said: "I can`t tell you the answer. This is Science, just Science. So follow the rule." I am frustrated by her reply, so I decided to ask expert in this forum.

[Delta1212]

You need two fluids because it is a hell of a lot easier to design two separate tools to perform two completely different tasks than it is to design a single tool that performs just as well at both tasks as a dedicated tool performs at each.

[Nicholas Kang]

Blood can somehow separate into 2 different places to perform 2 tasks at the same time. The blood will be different but they are still called blood.

[Endy0816]

CSF and really the blood brain barrier, permit the maintenance of an environment different than that found in the rest of the body.

 

Hormone producing areas of the brain are outside the BBB. Blood is used there. The bulk of your gray matter though is deserving of a bit more protection and seclusion.

 

I don't know what else you want from evolution. It has figured out a pretty decent way of keeping you alive and thinking.

Edited June 11, 2014 by Endy0816

[John Cuthber]

Blood can somehow separate into 2 different places to perform 2 tasks at the same time. The blood will be different but they are still called blood.

OK, we could call both liquids "blood".

What would it achieve?

The doctors would have to distinguish between the two sorts of "blood".

So, they would have to give them different names.

We would be back where we are now.

 

 

Also re

"If you say defense line, I will rather say solid body components to CSF, like bones, hard skull or strong skin structure."

You seem to have missed the point. If the blood goes to the brain there must be holes in the skull.

You can't use that to defend against bacteria and toxins.

However you can use the blood brain barrier as such a defence.

[Ringer]

Also, if you used blood to replace CSF you would need to produce a lot more blood. Producing a lot more blood would cause a huge dilution in the amount of proteins and such the must be produced. Then you would need a dedicated system to remove the proteins and such that would likely aggregate in such a large pool. Then there are the protections against. There are a large amount of other problems with just using blood as CSF because evolution has worked for generations to make them dedicated fluids.

 

Think of it this way, why do you have both a sink and a toilet if they both just drain water into pipes.

[Nicholas Kang]

I don't know what else you want from evolution. It has figured out a pretty decent way of keeping you alive and thinking.

 

You mean I am greedy? Or I am stupid? Or you are praising me?

 

 

 

OK, we could call both liquids "blood".

What would it achieve?

The doctors would have to distinguish between the two sorts of "blood".

So, they would have to give them different names.

We would be back where we are now.

 

How we call it? We can call it Blood A and Blood B or any other systematic taxonomy that is not to be confused with the blood group system.

 

 

 

CSF and really the blood brain barrier, permit the maintenance of an environment different than that found in the rest of the body.

 

I mean why CSF can exist? Is it evolved form blood? Or it is just naturally formed in the body? If blood and CSF have similarities, why not blood just alter its properties by DNA or gene in its component like cell to have the same configuration with the CSF, then we can just only have blood with different configurations and no such thing as CSF.

 

Also, if you used blood to replace CSF you would need to produce a lot more blood. Producing a lot more blood would cause a huge dilution in the amount of proteins and such the must be produced. Then you would need a dedicated system to remove the proteins and such that would likely aggregate in such a large pool. Then there are the protections against. There are a large amount of other problems with just using blood as CSF because evolution has worked for generations to make them dedicated fluids.

 

Think of it this way, why do you have both a sink and a toilet if they both just drain water into pipes.

 

Why produce more blood to replace CSF? Yes, it would need more blood if CSF don`t exist. But what I mean here is when blood reaches the brain can somehow alter its configuration to suit the brain`s need, thus function as the same as CSF, then we don`t need CSF.

 

Water in sink and toilet originated form the same source, the water reservoir. The water will be directed to sink and toilet. Water have their own functions respectively in 2 different conditions. In the sink, it is used to wash and clean plates, cups and kitchen utensils. In toilet, water is used for personal hygienic purposes. Finally, both of them flow back to the water treatment plant.

 

Analogy:

1. Water reservoir: Heart

2. Sink and toilet: Brain and other parts of the body respectively

3. Water treatment plant: Lungs

[John Cuthber]

 

 

How we call it? We can call it Blood A and Blood B or any other systematic taxonomy that is not to be confused with the blood group system.

 

Why not just call them blood and CSF?

That would avoid confusion.

Calling the fluid round the cerebrum and spine the cerebro-spinal fluid looks pretty systematic to me.

[Nicholas Kang]

Why not just call them blood and CSF?

 

No way because CSF and blood are different entities. While my proposed Blood A and Blood B(if you wish to call it this way) is originated from the same source-Blood. Blood A and Blood B are blood. But the current/present fluid that circulates our brain are 2 different things and not evolved form the same source. They can`t be altered by themselves through metabolic control and combine to become blood in the heart. But in my hypothetical situation, this is possible.

[Delta1212]

Why not just call them blood and CSF?

 

No way because CSF and blood are different entities. While my proposed Blood A and Blood B(if you wish to call it this way) is originated from the same source-Blood. Blood A and Blood B are blood. But the current/present fluid that circulates our brain are 2 different things and not evolved form the same source. They can`t be altered by themselves through metabolic control and combine to become blood in the heart. But in my hypothetical situation, this is possible.

Why is your scenario better than what we have?

[Nicholas Kang]

Because it is a scenario that makes sense and can happen.

[Endy0816]

Can you ensure your red blood cells are free of infection?

Can you prevent infectious agents from traveling in your bloodstream? How about toxins? Parasites?

Can you maintain a reasonably steady environment in your body?

While your pulling off these miracles you would need to work on making hormones more selective. Compared to the above this should be a relatively minor issue.

 

Seriously we'd be better off going the other way. We're not too far off with the research that has been going on into blood substitutes.

Edited June 12, 2014 by Endy0816

[Nicholas Kang]

Making hormone more selectively? This is not a bad idea. You mean research in blood substitutes shall cover substitution of CSF too?

[Delta1212]

Because it is a scenario that makes sense and can happen.

But clearly what we currently have is also a scenario that makes sense and can happen because it did happen.

[Nicholas Kang]

My scenario is better because you don`t need 2 entities but only one. You don`t have to waste time memorizing the word Cerebrospinal fluid but just Blood B. It makes taxonomy easier in certain sense because they originated from the common source.

Edited June 12, 2014 by Nicholas Kang

[Delta1212]

My scenario is better because you don`t need 2 entities but only one. You don`t have to waste time memorizing the word Cerebrospinal fluid but just Blood B. It makes taxonomy easier in certain sense because they originated from the common source.

Biology cares more about how well something works than how easy it is to define. Also, considering how arbitrary taxonomy is, making it easier isn't really an important virtue in the design of a system (especially since I think blurring the line between fluids with separate functions makes taxonomy harder. It's there to make distinctions so that we can understand what is going on better. If we wanted fewer names to remember, we'd just call everything in our body "Human Body Stuff" instead of bothering with distinct names for different tissues and structures.)

[Nicholas Kang]

I admit I lost. But, you see if compare your idea and mine, my idea is more of hypothetical. It might not be better than yours, but the same level as yours. So, now, we don`t argue which is better. We argue why yours is chosen during evolution and natural selection. Any opinions?

Edited June 12, 2014 by Nicholas Kang