How the fuck is blood delivered to every cell in the body? how

>>8910394
blood isn't delievered to every cell
blood is delivered to tissues
your blood is composed of cells and plasma and water
what do you mean between capillaries and cells? your capillaries are also made of cells

>>8910429
Yeah but aren't those tissues made of cells? Do the tissues themselves distribute that blood among its constituent cells or what?

I mean, how does blood reach every cell in the body every time it's pumped. How does it reach every cell in the body. I don't understand this.

File: 595px-Circulatory_System_en.svg.png (228KB, 595x842px) Image search: [Google]

228KB, 595x842px

>>8910394
Ok, blood is inside blood vessels, it doesn't just float around. There's a good picture in wikipedia showing the map of blood vessels in the human body (pic related).

Blood isn't "delivered to cells", blood is partly made up of cells. Blood is made up of plasma (the liquid that you associate with blood), and red and white blood cells. Plasma and the suspended red/white cells contain minerals and nutrients that need to be transported to tissues. The tissues are represented by the non-colored parts of the body shown in the pic. The interaction with the tissues happens through endothelial cells. Think of a vein/artery or a blood vessel, the blood is flowing through it but the vessel is surrounded by tissues that need nutrients. Endothelial cells are the cells that line these vessels, they are special because they can facilitate transport of nutrients by absorbing them and dispersing them into the tissues. This can happen by forming miniscule vesicles inside them and exocytosing them, or through simple diffusion, where nutrients in high concentration (aka nutrients in the blood liquid) automatically move into cells with lower concentration of nutrients (the endothelial cells that form the wall lining of those vessels). There are many other ways of transport but you get the idea.

>>8910454
>automatically move into cells with lower concentration of nutrients
that's osmosis, right? please don't laugh

I think I got it. But now I thought about something else. The way I see blood is like spraying water at a wall (tissue). Sure, the exterior of the wall of bricks gets a bit wet, but the water can't penetrate it and get into the deep layers of brick.

When blood reaches a tissue, how does blood get delivered past the initial layer of of that tissue it touches? I mean, when you get a minor skin cut, blood comes out. It comes out of a blood vessel or does it come out of the tissue? Does the tissue somehow distribute the contents of blood to each cell?
Do the blood vessels at some point "end" and have their job taken over by the tissues? "job" meaning the distribution of blood to each individual cell

If you really wanna get down into the mechanisms of molecular transport and how every cell gets nourished with oxygen, nutrients and other shit the answer is that most people don't know since we lack the technology and computer simulations to effectively guess what is happening. People don't understand the mechanisms of cellular intelligence, how cancer spreads or is cured. This is a massive feild run by Pseudo intellectual tards that flock to Reddit for advice on thesis's on molecular biology.

>>8910468
>that's osmosis, right? please don't laugh
No, that's passive diffusion. Osmosis is the opposite, from low concentration to high. Passive diffusion occurs automatically, no energy or action required. If the concentrates come into contact with cells with little concentration of that chemical, they move into the small concentration space to equalise the concentrations.

>The way I see blood is like spraying water at a wall (tissue)
Ok, I see your confusion. What actually happens is that the wall cells (endothelial) transport nutrients into the "interstitial fluid". This interstitial fluid is essentially the extracellular matrix of the whole nearby tissues. If you think of a tissue next to a capillary as a brick, then the interstitial fluid is the liquid in which the brick is bathed in, it's the liquid that allows transport into the "deep cracks" of that brick. The nutrients don't go directly from the capillary wall to the cells, they move into this liquid, which permeates the tissue throughout and delivers the nutrients to every cell. This should clear up your confusion.

Regarding the cuts, when you cut your skin, if you don't get any blood pouring out but you see a reddish wound, that means that you haven't actually destroyed the capillary/vessel. You can just see under your epidermis (cells that don't need blood, protective layer) and see the red. If you DO get bleeding, that means you have damaged the circulatory system i.e. the capillaries. If you get a cut that makes you bleed, you've broken the layers under the epidermis which DO need blood and have capillaries next to them, so they get damaged too and blood comes pouring out. Tissues on their own don't "bleed", bleeding occurs only when capillaries break.

>>8910516
>Osmosis is the opposite, from low concentration to high
Sorry about that, it's pretty late here and I'm not thinking clearly. Osmosis is the transport of the SOLVENT (typically water) rather than the solute (nutrients in our case) into a suspension with higher solute concentration.

The opposite to passive diffusion is rather active transport (which uses cell machinery and requires energy).

>>8910516
fuck, that's amazing, I knew what interstitial fluid was but I was no idea it had this purpose, now everything fits, I'm a bit less confused now thanks to you anon, thanks a lot!

and the last part is really interesting, I bite my nails and my fingers very often and I pull on the skin tags and stuff like that and some times I have bright red skin that hurts but there's no blood leaking out and I always wonder why, but now it makes sense

this question has been in my head for a looong time, thanks anon

>>8910530
I see. I only knew that it was responsible for snails dying when you sprinkle salt on them.

Thanks for those terms, you gave me some starting points from where I can branch, I'll search on the internet to find out more.

>>8910545
>>8910553
No problem, I'm actually glad this place could help somebody and escape the meme shitposting for a few minutes.

If you have any more questions ask away, I'll probably answer tomorrow though.

>>8910583
Okay, I've got one more question. Why do some substances get broken down into their constituents and turned into energy (calories) while other substances are treated more nicely and just enter the bloodstream and alter you in some way? They seem to be more powerful in some way, more complex than carbs and fat. I mean, why stuff like fat or carbs is turned into energy but vitamins / creatine / minerals / omega3 are not and are "more useful"? Protein too, parts of it are turned into energy = calories, but parts of it go around the body and help repair it, help make new muscle, repair tissue, etc.
Why isn't a vitamin just broken down and turned into energy? Or alcohol, which I think is turned partially into sugar / calories but what remains becomes a substance that alters the brain. I'm really tired now but this all seems magical to me, I mean, these substances have special powers while a sugar cube appears more dull, boring, it just gets used as shitty fuel.

I'm going to sleep too.

>>8910634
the enzymes that produce ATP are related to pathways for specific bio molecules. Carbohydrates, lipids, and proteins are all capable of being broken down for energy via glycolysis, beta-oxidation, and ketolysis respectively.
your body doesn't have efficient means for processing vitamins, like we cant even make some, primates are one of the only mammals that cant synthesize vitamin C

>>8910634
>Why isn't a vitamin just broken down and turned into energy?
Because a multicellular organism doesn't just need "energy". Having ATP (molecular currency for "energy" produced by cellular respiration) means you can move things around and help proteins synthesize new shit, but the proteins can't make things like DNA if there are no minerals to make the ATP itself, or DNA and RNA or cell membranes, all of which are essential to cell life. In turn, you need to regulate all these functions in specific systems. In order to do so, you need many different proteins that have specific binding affinities for specific cells in specific organs/tissues. Vitamins can have many functions, like Vitamin D, which indirectly helps regulate calcium absorption in the intestine by indirectly affecting gene expression. Other vitamins help enzymes (proteins) perform specific metabolic tasks.

Bottom line, if everything was broken down to "energy", life would not be possible. Life requires base materials (minerals), and signals to regulate all of its processes and keep the cell orderly and functional.

>>8910634
http://www.sigmaaldrich.com/technical-documents/articles/biology/interactive-metabolic-pathways-map.html

knock yourself out

>>8910394
Funny you should mention it, I was just talking to a kinesiology friend of mine about this.
Long story short
Nobody knows. You just have to come to accept there be some questions science don't want to answer and some answers we wouldn't understand.

>>8910836
What.