RHS Human A&P Unit 2a Muscular System Physiology

3 muscle types

skeletal, cardiac, smooth

Skeletal muscle

A muscle that is attached to the bones of the skeleton and provides the force that moves the bones.

Cardiac muscle

Involuntary muscle tissue found only in the heart.

Smooth muscle

Involuntary muscle found inside many internal organs of the body

Skeletal Muscle Diagram

Epimysium

Connective tissue that surrounds the entire muscle

Perimysium

Connective tissue surrounding a fascicle

Endomysium

Connective tissue surrounding a muscle fiber

Fascicle

bundle of muscle fibers

Muscle fiber

a single muscle cell

Involuntary muscles

Muscles that are not under your conscious control

Voluntary muscles

muscles that are under your conscious control

striated muscles

skeletal and cardiac

nonstriated muscles

smooth muscles

Muscle functions

producing movement, maintaining posture, stabilizing joints, generating heat

myofibril

A long, filamentous organelle found within muscle cells that has a banded appearance

Sarcolemma

plasma membrane of a muscle fiber

I band

thin filaments only; light band

A band

thick and thin filaments; dark band

sacromere

Basic contracting unit of muscle cell consists of actin and myosin filaments between z-lines in a muscle cell

thick filament

myosin protein

thin filament

actin protein