Yet another example of the gap between current medical practice and biological reality. In engineering situations I have long believed that people underestimate the complexity of fluid flow, even when talking about water or hydraulic fluid. An exposure to problems in liquid oxygen tanking on the Space Shuttle, convinced me this is true even of highly-trained professionals. (When something went wrong it took about 10 minutes for experts on consoles to decide that the numbers they were seeing meant the problem was real. Meanwhile, flow continued at something like 1,300 gpm.) Most of the systems I studied could be said to have quasi-steady flow, in normal operation, which is not true of most biological examples.
Now, I've learned about still another gap between medical research and practice. Biological circulatory systems are highly ramified: they branch, then branch again, until they reach some minimum size vessels. Flow in such networks is considerably different from the plumbing in your bathroom. Here's
a collection of papers from a research symposium which I am not planning to buy or read. The price is only one drawback. I have limitations.
How much difference does this make in medicine? It applies to highly vascularized organs like the brain, eyes, lungs, liver, adrenal glands and kidneys, to say nothing of the gut.
Oh, yes,
the pituitary and hypothalamus are other examples of highly vascularized organs where defects in microcirculation could cause serious damage with long-term consequences.