ELI5
Googles not doing it. Blood is carried through our veins but it’s also all over at once like when cut happens and that’s what give us our warmth, colour, nutrients etc. all over
I’m having trouble understanding how this blood is “all over” evenly spread.
The question is do we have free blood that not in veins and arteries? It’s seeming to me like we do???
How does blood “pool” and swell like a foot or a hand but not enlarge the veins and arteries if that’s where it’s carried?
Am I confusing myself?
EDIT!!! Y’all made that made that make so much more sense. So do capalaries end at where your pores begin? Like why you have blood in a popped pimple?
In: Biology
Blood moves through arteries and veins some of which you can see through your skin, however blood ultimately ends up in capillaries which are very small and run through and between nearly all the cells in your body. When you get a small cut most of the time its just the capillaries that were cut.
You should not have ‘free’ blood in your body, that is internal bleeding or near the surface a bruise.
You’re leaving out the capillaries. The arteries pump blood out into the body, and then they connect to tiny capillaries that go everywhere. The other end of the capillaries connect to the veins. From there it’s back to the heart and lungs to start the cycle again.
No pools, (that’s what a bruise is) just tiny tubes that let things pass through into and out of the adjacent cells.
The answer is capillaries my friend. Blood gets pumped all around your body from the heart and to get all its goodness into the tissues and organs it has to pass through tiny tiny blood vessels called capillaries. They are so thin that they can allow passage of the goodness (and passage out of waste). Think of arteries and veins like highways and main roads, and capillaries like the millions of residential streets that allow you to actually get where you want to go.
under normal operation our bodies have the perfect amount of blood in system to provide oxygen and nutrients to all cells. We do not have an emergency reservoir or secret stash of blood.
on a microsocopic level the components of blood are always dying; so our bodies are also making replacements….this leaves a balanced system not a net positive or negative.
under unusual circumstances inflammation, fatty deposits, gravity can make certain spots on our body (usually hands and feet) much harder for the blood to be pumped back towards the heart.
when damaged blood can escape the normal pathways and form a bruse
Veins and arteries are the big highways. Blood then spreads out into smaller *capillaries* that might be so narrow that only one red blood cells can go through them at a time. These capillaries don’t have to touch every single cell either. Nutrients and things get squeezed out of the blood vessels and directly “bathe” your tissues. Waste from your cells also goes out into this bath, and there’s a whole system in your body for cleaning and filtering this *lymph*. That’s what your lymph nodes do, btw.
Hello! I’ll try to give a rough ELI5 background of all this. Hope it helps.
A core detail of your circulatory system is that it has roughly four components, your heart which helps move blood around, arteries that carry blood away from your heart, capillaries which are very thin and more penetrable tubes, and veins which carry blood back towards your heart. Its as if you have a few large and very strong rivers, each of which progressively branch out into tiny rivers that deposit and pick up things, then merge back together to large rivers returning to the source (your heart). Each beat of your heart supplies the push and pull to keep it all moving. You also have two general loops going on here, with one going through your lungs, where these capillaries will pick up oxygen from your lung tissue, return to the heart, then go down the other loop to deliver it to the rest of your body, before returning and going back through your lungs once again.
Now, your blood actually has a lot of different components to it, and it carries all kinds of things that need to move around your body: oxygen, nutrients, hormone signals, water, and so on. At capillaries and the like, these can be exchanged through the walls–if the nearby tissue is very low in something (like oxygen, for exerted muscle tissue for example), it can be diffused into this tissue from your blood. If it’s very high in the nearby tissue (like carbon dioxide, waste, etc), it can be picked up by your blood and passed along elsewhere.
To further complicate it, you also have other local fluids and the like that assist in this relay of resources and different things, and signals that can change the characteristics of your circulatory system walls–for example, they can constrict, enlarge/relax, or be made more permeable. Different cells can also pass through them, in addition to resources and other things nearby.
If capillaries are damaged and the like, you can have small amounts of local bleeding (seen as bruising, often). Other more serious wounds can also cause internal bleeding and pooling. However there’s also cases where damage triggers a large influx of immune-related cells or fluid buildup (if something is going on, it’s deemed helpful to do this).
To answer your edit, capillaries are basically everywhere that’s alive and has the ability to heal.
So the *very* outermost layer of skin (which includes dead cells which we shed) doesn’t really have them, and it’s why very shallow cuts or scrapes might not bleed at all. Very few organs/tissues don’t have capillary beds. Ligaments, tendons and cartilage often have very little or no blood supply, which is one of the reason they heal so badly. (or not at all)
What comes out of a pimple is typically not blood, or not just blood, it’s a mixture of bacteria, white blood cells (which can come out of the capillaries to fight infection) and debris/dead cells, but if it’s badly inflamed and the tissue around got damaged, then yes, you can get blood as well.
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