Chapter 10, Problem 13CYR

Summary Introduction

Introduction:

The skeletal muscles are made up of long and multinucleated cylindrical cells, which are called fibers. The voluntary contraction of fibers results in the movement of a body part. The two main classes of skeletal muscle fibers are type I and type II fibers, depending upon the speed of twitch contraction and the energy source used by them. Type IIa and type IIx are the two subtypes of type II fibers of skeletal muscles.