Characteristic radius of capillary

Range ~5 µm
Organism Mammals
Reference Rosen, Optimality principles in biology, Plenum press 1967, p.55 3rd paragraph
Comments P.55 3rd paragraph: "A number of further indices of vascular structure may immediately be derived from the foregoing, and tested against empirical observation. Let us suppose, as a first approximation, that every vessel in the vascular system (except the aorta, of course) arises from a bifurcation of a larger vessel. Let us further assume that these bifurcations are optimal i.e. that the radii of the larger and smaller vessels involved in a bifurcation satisfy (3.21). Knowing that, in mammals, the radius of a capillary is about 5 x 10^-4 cm, it is therefore pertinent to ask for the number n of bifurcations necessary to pass from an aorta of radius ra to a capillary of radius 5 x 10^-4 cm by successive bifurcations." There are allometric relationships that show the scaling with body mass see: Scaling Laws for Capillary Vessels of Mammals at Rest and in Exercise, Thomas H. Dawson, Proceedings: Biological Sciences, Vol. 270, No. 1516 (Apr. 7, 2003), pp. 755-763. "...inner diameter [in human] is as small as 3µm." according to PMID 20387977 p.2260 top paragraph
Entered by Ron Milo - Admin
ID 100795