Marie and Cheer,
Maybe I put too much emphasis on the Zamboni paper. When I started reading it I thought it was cool how the blood can get around in a variety of circuits. How the V-Plex can empty into the L-REN and that can go either to the IVC or the AZY. It made real sense to me (from the diagrams) that a blockage in the L-REN would send blood back up the VPlex into the VVs. So now it's really hard to undo that when my basis for understanding how blood backs up and has to flow out another way (thereby causing excessive pressure in unexpected places) isn't working when I find that a lot of these things aren't even connected. Believe me, I'm TRYING. Then I google Intrarachidian Circle and I can't identify that as a part of the body. I need to break this all down into small pieces, but even that doesn't seem to work.
So I drew an Azy on the picture above. I can also see from Gray's that the horizontal veins that come off the Azy are called Intercoastal Veins. I wonder if those are the 4 lines that lead into the Azy in Zamboni's diagram.
So before I continue, It's clear to me that things aren't as close together and linked as I previously thought. Now I need to try to see how they are linked, if at all and then how they effect each other. Now I CAN see, from my diagram above, how blockage in the IJV's might cause added pressure on the VV. Maybe we work with that.
Huge IJV/VV Question: How does the blood get redirected in the brain/head? Meaning (I'm going to have to use analogies here), in your house, a blocked toilet doesn't nessessarily mean the bath tub stops up, UNLESS, they are both linked at a "Y" somewhere, then blockage, clearly causes reflux, ick. But, as I understand the vein system, it starts at branches that work down to a trunk, so, where would two downflowing veins meet up from a junction? Meaning, the IJV and VV are like ---- it's like the toilet pipes coming to a junction where it splits into 2 pipes that take the waste out to the septic tank - a backwards use of the "Y" junction.
The only way this makes intuitve sense to me is if the brain is more like a ..... how about a sponge-filled whiffle ball. A bunch of inflows and a bunch of outflows that should yeild a normal pattern of certain inflows normaly going to certain places of outflow. But if one outflow get's blocked, the blood has to work it's way through the sponge to find another outlet. But, even this analogy causes probelms for me, the blood flow in the brain has to be more controlled than that, and wouldn't a blockage cause stroke or something like that? This discussion is purely speculative - entirely sourcing from my frustration in trying to understand seemingly simple diagrams. If I can find that the intercoastal veins meet up with the vertebral plexus, I'll feel like I've accomplished something. I hope the vertebral plexus is in the spine............
Have a great weekend! Ken
edit: Newer and maybe better analogies - a) the outbound sewer system that sends waste water to a treatment plant in a very controlled and leakproof network and b) the irrigation of a field were water comes in from a single source and it's distribution is not controlled very much.