dcs1289

dcs1289 t1_ja5gmjc wrote

Lots of R&D in the battery tech sector ongoing; what you say is true currently but absolutely will not be the case forever.

And if we're talking about environmental impact, Li mining vs. fossil fuels is a very silly argument considering the ongoing climate change trends. Best to keep our planet habitable in the short term and worry about lithium reserves and recycling down the road. Just one more can to kick.

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dcs1289 t1_j9i74cj wrote

Capillaries are everywhere. It's the end point of the circulatory system everywhere, so there are beds of capillaries in basically any living tissue.

Probably the most well-known tissue with poor/limited blood supply is tendons/ligaments - these are connective tissues with a lot of intracellular matrix made up of collagen, and blood supply to these tissues is poor the further you get from the source blood vessel as there is often very little collateral circulation (what it's called when an area has multiple arteries that feed the capillary beds).

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dcs1289 t1_j9huya2 wrote

The blood cells don't actually leave the capillaries if everything is going fine. The capillary bed is basically a mesh of VERY tiny blood vessels - picture two sets of tree roots with the bottom portion of the roots aiming towards each other and connected - arteries (tree trunk on the left of your mental image) diverge into smaller arterioles which diverge more into capillaries.. which merge back together into venules, which merge into veins (tree trunk on the right).

When the blood is moving through the capillaries, exchange of oxygen and nutrients is able to occur through small pores in the cells (or straight across the cells in some cases). The blood cells don't leave the circulation, but the plasma that they float around in can move back and forth through the tiny gaps.

Here's a good picture to describe the mental image I'm trying to verbalize above.

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