Assertion: capillary tube | /r/HasAspect | muscle fibres
Facets:
value: unlike the capillaries
type: OTHER
Source sentences:
text: Between the smallest arteries, or arterioles, and the capillaries are intermediate vessels called precapillaries, or metarterioles, that, unlike the capillaries, have muscle fibres that permit them to contract; thus the precapillaries are able to control the emptying and filling of the capillaries.