regular muscle-prism

From regular +‎ muscle +‎ prism.

regular muscle-prism (plural regular muscle-prisms)

1. (physiology) A simplified, geometric block representing a bundle of parallel muscle fibers; an old teaching model used for explaining tension, cross-sections, and electrical properties of muscle.
   • 1881, Rosenthal, Isidor, chapter XI, in General Physiology of Muscles and Nerves‎^[1], page 189:

     Taking a regularly shaped muscle in which the fibres are parallel, we will cut out a part of this by making two even cuts at right angles to the direction of the fibres. A piece of this sort may be called a regular muscle-prism. It is, according to the shape of the muscle used, either circular or more oval, or flat and band-like ... all the muscle-fibres are parallel to each other, [and] the two cuts are made at right angles to the direction of the fibres.

   • 1892, William Morrant Baker, Vincent Dormer Harris, chapter XI, in Hand-book of Physiology‎^[2], page 460:

     ... and a muscle of regular shape, in which the fibers are parallel, is selected. The ends are cut off by clean vertical cuts, and the resulting piece of muscle is called a regular muscle prism.

   • 1912, Starling, Ernest Henry, Principles of Human Physiology‎^[3], page 264:

     When the muscle is at rest the contents of the muscle prism will be in equilibrium with the surrounding sarcoplasm ... pressure in the muscle prism rises and causes a bulging of its lateral wall and a shortening of the whole element.