Muscles and Muscle Tissue Converting ATP into mechanical energy….thereby capable of exerting force

Muscles and Muscle Tissue

Converting ATP into mechanical energy….thereby capable of exerting

force

Types of Muscle Tissue

•Skeletal•Cardiac•Smooth

Critical Terms

• Muscle fibers – skeletal and smooth muscle cells which are elongated

• Myofilaments – two kinds of fibers responsible for contraction (actin and myosin

• Myo or mys; sarco – prefixes that reference muscle

• Sarcolemma – plasma membrane• Sarcoplasm – muscle fiber cytoplasm

Skeletal Muscle Tissue

• Attach to and cover the bony skeleton• Longest muscle cells• Striations • Voluntary control – subject to

conscious control

Cardiac Muscle Tissue

•Occurs only in the heart•Makes up the bulk of the

heart wall• Striated and involuntary

Smooth Muscle Tissue

• Found in walls of hollow visceral organs• Forces fluids and substance

through internal body channels• Nonstriated and involuntary

Functional Characteristics

• Excitability – responsiveness/irritability• Contractility – ability to shorten with

adequate stimulation• Extensibility – ability to be extended• Elasticity – ability to recoil and

resume length after being stretched

Muscle Functions

• Production of movement – locomotion and manipulation• Maintaining posture• Stabilizing joints• Generating heat • Protects viscera

Skeletal Muscle

• Each muscle is served by one nerve, artery, and one or main vein

• Each muscle supplied with nerve endings • Requires supply of oxygen and nutrients• Emit large amounts of metabolic waste

Connective tissue sheaths Endomysium – surrounds each muscle fiberFascicles – groups of muscle fibersPerimysium – surrounds each fascicleEpimysium – surrounds the whole muscle

Series elastic components

Contraction pulls on sheaths, pulls on the bone or tendon…contributes to

elasticity

Attachments

• Insertion – attachment to the movable bone• Origin – attachment to the immovable bone can bea.Direct – epimysium is fused to periosteum of

bone or perichondrium of cartilageb.Indirect – tendon (ropelike)

aponeurosis (sheath like)