General physiology of muscles and nerves . Fig. 25. Smouth .MLSCLii-Kiisiiiis (oOO toiks enlarged). the circumference, and to shorten the length of thewalls of the tube in which they occur. This is of greatimportance in the case of the smaller arteries, in whichthe smooth muscle-fibres, arranged in the form of aring, are able greatly to contract, or even entirely toclose the vessels, thus regulating the current of bloodthrough the capillaries. In other cases, as in the in-testine, they serve to set the contents of the tubes inmotion. In the latter cases the contraction does net 98 PHYSIOLOGY O
General physiology of muscles and nerves . Fig. 25. Smouth .MLSCLii-Kiisiiiis (oOO toiks enlarged). the circumference, and to shorten the length of thewalls of the tube in which they occur. This is of greatimportance in the case of the smaller arteries, in whichthe smooth muscle-fibres, arranged in the form of aring, are able greatly to contract, or even entirely toclose the vessels, thus regulating the current of bloodthrough the capillaries. In other cases, as in the in-testine, they serve to set the contents of the tubes inmotion. In the latter cases the contraction does net 98 PHYSIOLOGY OF MUSCLES AND NERVES. take place simultaneously througliout the length of thetube; but, commencing at one point, it continuallypropagates itself along fresh lengths of the tube, so thatthe contents are slowly driven forward. The principalagents in this are the circularly arranged fibres, whichat one point completely close the tube, while, by thecontraction of the longitudinal fibres, the wall of thetube is drawn back over its contents, th
Size: 1350px × 1850px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookd, booksubjectmuscles, booksubjectphysiology
