Hey everyone! Hope all is okay.
Before we begin, I just had a quick question- to all my fellow bloggies out there, do you know how to tag posts? I’ve been trying, but I’ve no clue. I’m not all that good with tech, so…😅
All right, let’s do this!
Today we’re only gonna talk about blood vessels. I know, sounds pretty stupid. People are like, “Oh, okay, blood vessels. They’re just these long tube things that carry blood. Simple…”
Noooooo, not simple! Blood vessels are uniquely adapted to their purpose, and carrying blood around the body is NO easy task. We may think it’s really basic- “Yeah, the heart does all the work. Pumps all the time. Blood vessels just carry the stuff.”
But they’re actually a certain kind of genius. I’ll stop ranting like some blood vessel obsessed weirdo, but you get my point- do not underestimate the power of blood vessels.
The Types of Blood Vessels->
Now, there aren’t really “types” as such. However, blood vessels have three main bifurcations- arteries, veins and capillaries. Arterioles and venules also exist- but they’re basically smaller versions of arteries and veins respectively. Capillaries are insanely tiny- they are actually thinner than a single strand of human hair! They penetrate to every single part of the body- capillaries have such an extensive network that no body cell is too far away from a capillary…
Arteries are the blood vessels that carry fresh, oxygenated blood away from the heart. The pulmonary artery is the only artery in the entire body that carries deoxygenated blood.
Besides their differing functions, arteries and veins have different structures too. What’s really great is that their structures are adapted to their different functions. It’s a little bit strange- carrying blood away from the heart or to the heart can’t be all that different, no? But it is! It’s REALLY different!
For example, arteries have thicker and more muscular walls, because the blood that rushes through them comes in at a very high pressure. To withstand the pressure, they need strong walls. Not to mention- they have elastic bundles too! Remember what I said about pulse in my last post? Yeah- so, they need to be elastic enough to recoil back to their normal position with every pulse! Awesome, right?
Veins are blood vessels that carry deoxygenated blood back to the heart. Just like arteries, there is only one veins exempt to this rule- the pulmonary vein. It is the only vein to carry oxygenated blood.
Veins, unlike arteries, have valves- which you can see in the above GIF. The blood in veins is of low pressure- so it can often flow backwards and away from the heart, instead of to the heart. Valves help to keep blood flow unidirectional by opening and closing at the correct times.
Not to mention- veins have thinner walls, too. This is, once again, due to lack of pressure in the blood- there’s no real need for the walls to be thick or strong.
Capillaries are really, really thin. They actually have only one cell thick walls- so that diffusion is quick and easy.
They’re basically responsible for delivering oxygen and other requirements to body cells, and then taking away the waste products. Molecules can diffuse across the thin layers with great ease, speeding up the entire process!
That’s it for today, guys. Any questions? Head to the comment section!
Thanks for reading, and see you in a couple weeks!