Chapter 4, Problem 5A

Summary Introduction

Introduction:

The smooth muscles are elongated cells with a spindle shape. They are uninucleate with a single nucleus. They do not have any markings or striations. They have an involuntary action. There are located on the walls of blood cells containing endothelial cells and on the lining of digestive tract in humans. The skeletal muscles have marking with striations of fibers. They are voluntary muscles which respond to stimuli. They have cells with many nuclei. The fibers are made of actin and myosin filaments. The cardiac muscles have markings and striations which contract to help in the flow of blood from the heart to the various organs. There are various intercalated disc present in the cardiac muscle fibers.