Question

Muscle contractions have _____ force at slower shortening contraction velocities compared to higher shortening contraction velocities.

Answer 1

Answer:

increased

Explanation:

The set of nerve fiber and muscle fibers innervated by it, form a functional unit called MOTOR UNIT. From the contractile point of view, the skeletal fiber works under the principle of “all or nothing”, since the arrival of an action potential produces a release of saturating calcium, in the case of the other types of fibers, the gradation of The calcium leakage causes the degree of contraction to be controlled and not governed by the same principle. There are large motor units such as those located in the muscles of the legs (2,000 fibers / motor unit), and, on the contrary, those located in the muscles of the fingers, eyes or larynx have a very small size (5 -6 fibers / motor unit).

The shortening speed in an isotonic contraction depends directly on the load, if an isolated muscle is attached to a weight and left at rest on a table. If the muscle is stimulated and the force generated in the contraction does not exceed the weight, the weight will not move and an isometric contraction will be obtained. If the force generated is greater, then the weight rises and the contraction will be isotonic. If the applied load is large the shortening speed will be small, if lower and lower loads are applied, the speed will increase and the maximum will be reached when the load is zero.