Top 9 numbers you should know about your super organism (super body) if you want to sound smart at a party.

*The text was written in 2016, so some numbers, ideas, articles mentioned here may be out of date.

    To better deal with ageing, it's good to know a bit about an organism you have (and that knowledge also helps at some parties). So, have you ever wondered how big you actually are?

    As you know, human body is kind of a complex entity (usually). On the most general level it's only one human being, but underneath there are hundreds/thousands/millions of systems, organs, cells...
Well, do you know how many exactly? If you want to find out about number of body systems, organs, tissue types, cell types, brain cells, body cells, etc. that are in one human, you are in the right place.
So...
Let's start with something simple.

[question 1] Do you know how many body systems humans have?

[answer 1] Body systems:
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11.

Humans have 11 body systems. These are: (1) integumentary system, (2) cardiovascular/circulatory system, (3) respiratory system, (4) digestive system, (5) endocrine system, (6) muscular system, (7) urinary system, (8) skeletal system, (9) reproductory system, (10) immune system, and finally (11): also known in some circles as "the one to rule them all" - repro..., oh wait - not that..., the nervous system. And that's it. These are the systems of human body. But it's just a beginning - the top layer of body organization.

*some say that lymphatic system is 12th system (not part of immune system)

More: (1-1) Human Physiology: From Cells to Systems, Eighth Edition. Lauralee Sherwood, 2013.

 

[question 2] So, the next question is - do you know how many organs are there in these systems? Take a guess.

[answer 2] Organs
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79.

Congrats if you got it right. Humans actually don't have that many organs in their bodies, because, well... humans are boys and girls and... you know, there are some differences. And the number 79 is the number of all human organs we know. Anyway...
Fun fact about human organs is that just couple of years ago there were only 78 organs. True story. And one day, miraculously, people gained one more organ. Ok. Some say that it was always there, but others feel like they gained couple more pounds because of this new organ (for sure, that's the reason). One way or another, all need to learn to live with it and take care about it the same way they've taken care for all others since they were born. So, as they say - it's one more to feed, but it's also one more to play with, to love, and you know... Oh, and the name of this new organ is...:
the Mesentery. And that's it about organs.

Now, the next layer: tissue types.

More: (2-1) (2-2 PDF file) (2-3)

[question 3] How many tissue types you think we have that build up all these organs and systems?

[answer 3] Tissue types
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And the winner number is... 4.

4 types of tissue is enough to build 11 body systems and 79 organs. Maybe it's not much, but... Well, you know - Ockham's Razor rules.
So, what are those tissue types? They are: muscle, nervous, epithelial and connective.
And that's it. 4. So let's move further... deeper. The next question is...

More: (3-1) Human Physiology: From Cells to Systems, Eighth Edition. Lauralee Sherwood, 2013.

[question 4] Right now, you already know that there are 4 tissue types. Knowing that, how many different cell types you think are there in human organism? Take a guess.

[answer 4] Cell types
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And the winner number is... not 4.

2100.

There are about 2100 different cell types in human organism. At least, that's the number we believe in now. This number was learned by checking the epigenetic differences between cell types. These differences influence the way our genome works, what types of proteins are made in the cell, etc., and thus are the reason our body cells may have different functions.
So - 2100. That's it.
Ok. If you knew all that - you rule. If you didn't - you know it now. Congrats.

More: (4-1)

And now, either way - to gain knowledge and store it, you need brain. And brain needs cells. So the next question is - how big, you think, your brain is. And to be more precise...

[question 5] How many neurons are in human organism? Pick your brain and try to answer the question using all neurons you have.

[answer 5] Neurons
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86 000 000 000

86 billion neurons. That's how many neurons are in human brain.
Well, you probably have more, but typical human being has approximately 86 billion of them.
It means that there is 10 times more neurons in one human being than human beings on one Earth.
Ok, so we got to kind of a big number with these neurons, but that's not all there is to count, and the next question is already here... Are you ready?

More: (5-1)

[question 6] You know how many neurons are in your brain, so how many cells, you think, build up the whole human body?

[answer 6] Body cells

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Ok. Now - these estimations become more and more estimated, because nobody actually counted cells in human body, but scientists estimate that there are... (and the drum rolls, please)

30 000 000 000 000 (30 trillion)
cells that constitute human body

That is a lot. A lot.

And in each of these cells there are organelles, like nucleus, mitochondria, Golgi Apparatus, etc. The cells differ and the number of organelles in each cell differs a lot, because cells have different functions and different sizes.
In the future we'll probably know about number of organelles in each cell type, but that's not so near future.
Meanwhile, let's go deeper and try to estimate something else. Let's assume we are now looking through a really good microscope. The magnitude is enormous and we see all the molecules in each cell. And we even see all the atoms in these molecules. Cells, of course, have different amount of various molecules, but we can estimate how many molecules are in the whole body and how many atoms are in these molecules and thus we can estimate how many atoms are in the whole human body.

More: (6-1)

[question 7] How many atoms you think there are in all these molecules in one human body?

[answer 7] Atoms in body cells
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7 000 000 000 000 000 000 000 000 000 (7*10^27 atoms)

Now, that is a big number. Even bigger number would be the number of all protons or neutrons that are in these atoms, but...

But, wait for it, it's not the whole number of cells, molecules, and atoms that are in your superorganism. By the way, you are a superorganism, if you didn't know it yet. That means (being superorganism) that you are not alone in your body, and you cannot survive alone. In order to live, you need help from other organisms that are inside you. So, in your superorganism there is you and there are a lot of bacteria that live in your guts. And they are pretty important for your health.

More: (7-1)

[question 8] So let's go back for a while. Remember, you have approximately xxx cells in your body. So, how many bacteria cells you think live inside your superorganism?

[answer 8] Bacteria in superorganism:
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39 000 000 000 000

39 trillion. So, there is more bacteria cells than your own body cells in your superorganism. That's huge, don't you think.
Ok, when you weigh those bacteria, the proportion changes, and still - you could lose 0,2 kg (0,5 pounds) if you got rid of these bacteria. But you probably shouldn't do that.

More: (8-1)

[question 9] And that concludes the journey through your superorganism. Now, there is only one more number you should know regarding human organism: 122. Do you know what it is?

[answer 9] 122

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It's the number of years the oldest person ever lived. Jeanne Calment. She was the oldest person that ever lived, according to scientists.
And 122 is the number you might be able to achieve with good nutrition, activity, social interactions, medical care, etc. This is the number you can beat if you know enough about your organism and take good care of it and if you are lucky. Assuming you are less than 80 now means that you still have 40 years to live, so don't worry, be happy (as they say). Think what you can do in these 40 years and start today.
Whether you decide to go for the crown and become the oldest person ever or not, remember - there is a lot of you, but in the end, it all comes to 1. 1 life you have.

More: (9-1)

[the end... or not...] Have a great life with your superorganism.