ronigamiHow bad would it be to inject seawater into your bloodstream?
Maybe you should buy one of those kids microscopes and see how much small stuff floats in a single drop of water. I didn't try seawater as a kid, but water from a pond has millions of moving, living things in it.
Yeah there is a lot of stuff in the water but there’s a lot of stuff in the air. Each day you come in contact with tens of billions of viruses, right?
And you have a lung as a barrier. That's supposed to exchange the oxygen and carbon dioxide, while keeping most of the rest out of the bloodstream. Nose, mucusa, bronchia also do their thing. I mean you also don't inject air into your blood vessels...
So basically the immune system just kind of sucks? I mean trees don’t have one and they’re fine so I guess it’s just supplementary and not that effective compared to other things?
Your body is one system. Your blood cells, lungs, bronchia all collaborate and work together to pull off the task. I'm not sure if "sucks" is the right word here. But you won't survive without a lung nor will you survive without blood cells and that part of the immune system
And concerning trees, they have an immune system as well: www.nature.com/articles/nature05286
Sort of, but not on the same scale as us. Generally, the default for anything not a vertebrate is to have innate immunity systems like inflammation, but no adaptive response. Although, there are parallels to white blood cells that have separately evolved in certain other branches of the animal kingdom.
The plant immune system - Nature
An understanding of the immune system of plants is important for progress in agriculture and pest control. Lacking the mobile defender cells and adaptive immune response found in mammals, plants rely on the innate immunity of each cell and on signals sent around the plant from infection sites. Jonathan Jones and Jeffery Dangl review current models of plant defences, and identify some of the remaining unknowns, including the mechanism used to arrest growth in pathogens.
Sure, I mean trees and humans are very different species and have different inner workings. Though I'm pretty sure it's worthy of the name immune system. Plants have specific proteins to handle things, and I believe they can even send chemicals through the organism to respond.