After yesterdays short night today I found myself studying my red eyes today. Some of the blood vessels look remarkably like miniature rivers, in the way that they meander across my eye ball. So my question is why do they grow/flow in this way? I know why and how naturally flowing rivers meander, but I can’t imagine that same priciple at work here.
This couldn’t be the first time the SDMB let me down, could it? Any ideas, anyone?
Why not? Rivers follow the path of least resistance. So do growing blood vessels. They’ll take the easiest path (metabolically) that ensures proper blood flow to the affected tissue. This doesn’t necessarily mean the shortest or most geometric path.
QtM, MD
I was originally going to suggest that perhaps there wasn’t a specific reason for it, that maybe meandering eyeball blood vessels simply never presented an evolutionary impediment, and thus were never selected against. However, after considering the situation for a bit, I’ve come up with one possibility. Unlike virtually all other body parts, the eyeballs each have only one relatively thin shell through which blood vessels can penetrate, since they eyes are, by necessity, essentially hollow (intraocular fluid notwithstanding). Because of this, the veins and arteries here must find a way to maximize their delivery of nutrient- and oxygen-carrying blood. One way to do this is to “fold up” the paths they take, in much the same way that the lungs maximize their surface area, yet occupy a relatively small volume. Hence, meandering blood vessels.