Capillary diameter and geometry in cardiac and skeletal muscle studied by means of corrosion casts
Two articles on PainSci cite Potter 1983: 1. The Complete Guide to Patellofemoral Pain Syndrome 2. Ugly Bags of Mostly Water
PainSci notes on Potter 1983:
I went looking for this paper because I wanted to know how big capillaries are, and how that compares to thinks like spider silk and human hairs. Both hair and silk come in a wide variety of thicknesses, but this fact is routinely ignored. For instance, spider silk will be described as being a tenth the thickness of a human hair. Which spider? Whose hair? I haven’t documented my sources because it’s a trivial, gee-whiz point, but the process of clearing this up was interesting. Turns out that human hair diameter ranges from about 15 micrometres at its finest, all the way up to 200 micrometres at the thickest: a full order of magnitude difference! Capillaries, on the other hand, are more consistent at around 4-6 micrometres: something like a third to a fortieth the thickness of hair, depending on the hair. Definitely smaller! Now spider silk turns out to have a really wide range of sizes. The very thinnest is measured in nanometres, just 10 of them, which is really impressive (nanometres are used to measure things on the molecular scale). At the other end of the range, spiders sometimes pump out silk as thick as 150 micrometres, a relatively gargantuan tenth of a millimetre and about the same size as the heaviest hairs. So, capillaries can be up to 500 times larger than really fine spider silk, or about thirty times smaller than the thickest.
This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights:
- Inciting events associated with lumbar disc herniation. Suri 2010 Spine J.
- Prediction of an extruded fragment in lumbar disc patients from clinical presentations. Pople 1994 Spine (Phila Pa 1976).
- Characteristics of patients with low back and leg pain seeking treatment in primary care: baseline results from the ATLAS cohort study. Konstantinou 2015 BMC Musculoskelet Disord.
- Effectiveness and cost-effectiveness of universal school-based mindfulness training compared with normal school provision in reducing risk of mental health problems and promoting well-being in adolescence: the MYRIAD cluster randomised controlled trial. Kuyken 2022 Evid Based Ment Health.
- No long-term effects after a three-week open-label placebo treatment for chronic low back pain: a three-year follow-up of a randomized controlled trial. Kleine-Borgmann 2022 Pain.