Chapter 10 Skeletal Muscle Tissue - Vocabulary Flashcards

Vocabulary flashcards covering key skeletal muscle tissue terms from the notes.

Skeletal muscle tissue

Type of muscle tissue attached to bones that enables voluntary movement, maintains posture, stabilizes joints, generates heat, and supports bodily functions.

Contractility

Property of muscle tissue that allows it to shorten forcefully when stimulated.

Excitability

Property of muscle tissue that enables it to respond to stimuli, such as nerve impulses.

Extensibility

Property of muscle tissue that allows it to be stretched beyond its resting length without damage.

Elasticity

Property of muscle tissue to return to its original length after being stretched.

Produces movement

Muscle action that moves bones and body parts.

Maintain posture

Constant muscle activity that helps keep the body in an upright position.

Stabilize joints

Muscle action that helps stabilize joints during movement.

Generate heat

Contraction of muscles releases heat as a byproduct of metabolism.

Open/close body passageways

Muscle action that regulates openings such as sphincters and passageways.

Movement of organs and blood vessels

Muscle contractions help propel contents through organs and vessels.

Cardiac contractions

Contractions of cardiac muscle that pump blood through the heart.

Myo- prefix

Prefix meaning muscle.

Mys- prefix

Alternative form of the prefix meaning muscle.

Sarco- prefix

Prefix meaning flesh.

Origin

Attachment site of a muscle to the part of the skeleton that remains relatively fixed during contraction.

Insertion

Attachment site of a muscle to the bone that moves during contraction.

Epimysium

Connective tissue sheath around the entire muscle.

Perimysium

Connective tissue surrounding a fascicle (bundle of muscle fibers).

Endomysium

Connective tissue surrounding each individual muscle fiber.

Fascicle

A bundle of muscle fibers within a muscle.

Muscle fiber

A single skeletal muscle cell that contains myofibrils.

Tendon

A tough connective tissue band that attaches a muscle to bone.

Myofibril

Long, cylindrical organelle inside a muscle fiber that contains the myofilaments.

Sarcomere

The functional unit of a myofibril; a segment between two Z-discs.

Myofilament

Protein filaments (actin and myosin) within a sarcomere.

Actin (thin) filament

Thin protein filament that participates in contraction.

Myosin (thick) filament

Thick protein filament with heads that bind actin during contraction.

Z disc

Boundary between sarcomeres; anchors actin filaments.

I band

Region of a sarcomere containing only thin filaments (actin); light band.

A band

Region of a sarcomere where thick and thin filaments overlap; dark band.

H zone

Central region of a sarcomere with only thick filaments; shortens or disappears during contraction.

M line

Center line of a sarcomere that anchors thick filaments.

Sarcolemma

Plasma membrane of a skeletal muscle fiber.

Sarcoplasmic reticulum

Membrane network that stores and releases Ca2+ during contraction.

Troponin

Regulatory protein that binds Ca2+ and moves tropomyosin to expose actin binding sites.

Tropomyosin

Regulatory protein that covers actin binding sites; moved to enable contraction.

Calcium (Ca2+)

Ion released from the sarcoplasmic reticulum that triggers contraction by enabling actin–myosin interaction.

Sliding filament mechanism

Process by which sarcomeres shorten as actin and myosin filaments slide past each other during contraction.

Neuromuscular junction

Synapse between a motor neuron and a skeletal muscle fiber where ACh is released to stimulate contraction.

T tubules

Transverse invaginations of the sarcolemma that propagate action potentials into the muscle fiber.