Introduction * Motion * Results from alternating contraction (shortening) and relaxation of muscles * Skeletal system * Provides leverage and a supportive framework for this movement * Myology – study of muscles
Muscle Tissue * Alternating contraction and relaxation of cells * Chemical energy changed into mechanical energy
Types of Muscle Tissue * Skeletal muscle – primarily attached to bones * Striated and voluntary * Cardiac muscle – forms the wall of the heart * Striated and involuntary * Smooth (visceral) muscle – located in viscera * Non-striated and involuntary
Striated “striped”
Skeletal Muscle * Attaches to bone, skin, or fascia * Striated with light and dark bands * Voluntary control of contraction and relaxation
Cardiac Muscle * Striated in appearance * Involuntary control * Auto-rhythmic because of built in pacemaker
Smooth Muscle * In walls of hollow organs blood vessels and GI * Nonstriated in appearance * Involuntary
Functions of Muscle Tissue * Producing body movements * Stabilizing body positions * Regulation organ volumes * Bands of smooth muscle called sphincters
Functions of Muscle Tissue * Movement of substances within the body * Blood, lymph, urine, air, flood and fluids, sperm * Production of heat * Involuntary contractions of skeletal muscle (shivering) * Excitability * Respond to chemicals released from nerve cells
Properties of Muscle Tissue * Conductivity * Ability to propagate electrical signals over membrane * Contractility * Ability to shorten and generate force * Extensibility * Ability to be stretched without damaging the tissue * Elasticity * Ability to return to original shape after being stretched
Skeletal Muscle Tissue
Each skeletal muscle, is a separate organ, composed of