Unit 4 – Introduction to Muscle Tissue

Introduction to Muscle Tissue

Muscle tissue is designed to contract or shorten to provide movement of or support to other body tissues.  Three types of muscle tissue exist in the human body.  Skeletal muscle tissue consists of large cells under voluntary control that cause movement of the body or support body structures by pulling on bones, cartilage, or other connective tissues when they contract.  Cardiac muscle tissue is found only in the myocardium of the heart and consists of smaller cells under involuntary (autonomic) control.  Rhythmic contraction of cardiac muscle cells causes the heart to pump blood through the cardiovascular system.  Smooth muscle tissue consists of tiny cells under involuntary (autonomic) control.  Smooth muscle cells are usually organized into sheets or bands of thousands of cells in the walls of blood vessels and tube-like organs of the digestive, reproductive, urinary, and lower respiratory tracts.  Smooth muscle provides mechanical support for the walls of tube-like organs and controls important functions such as peristalsis, dilation/constriction, and regulation of sphincter activity.

This unit contains separate chapters that provide an overview of the structure and function of each muscle tissue type (cardiac, skeletal, and smooth) and additional chapters that cover the basic structure and function of neuromuscular junctions and the structure of skeletal muscle-tendon junctions.  There is also a chapter that provides numerous muscle tissue quizzes and interactive learning activities.