Muscle Tissue

Flashcards covering key concepts related to muscle tissue and its functions.

Muscle Tissue

A primary type of tissue, consisting of three types: Skeletal muscle, Cardiac muscle, and Smooth muscle.

Skeletal Muscle Functions

Produces movement, maintains posture, supports soft tissues, guards body entrances and exits, maintains body temperature, and stores nutrients.

Epimysium

Layer of collagen fibers that surrounds the muscle, connected to deep fascia, and separates muscle from surrounding tissues.

Perimysium

Surrounds muscle fiber bundles (fascicles) and contains muscle fibers.

Endomysium

Surrounds individual muscle cells (fibers) and contains myosatellite cells which repair damage.

Myofibrils

Lengthwise subdivisions within a muscle fiber responsible for muscle contraction, made of bundles of protein filaments (myofilaments).

Sarcomere

Smallest unit of a muscle fiber; myofilament interactions produce contraction, and arrangement creates striations.

Calcium Role in Contraction

When stimulated, Ca2+ is released in muscle fiber, allowing myosin access to actin and enabling cross-bridge formation.

Excitation-Contraction Coupling

The process by which action potentials lead to muscle contraction via Ca2+ release from the sarcoplasmic reticulum.

Twitch

A single neural stimulation producing a single contraction, with phases: latent, contraction, and relaxation.

Isometric Contraction

Active muscle contraction without changing muscle length, such as during arm wrestling.

Isotonic Contraction

Generation of muscle force with constant tension and change in muscle length.

Fast Fibers (Anaerobic)

Contract quickly but fatigue fast, large diameter, and dependent on anaerobic glycolysis.

Slow Fibers (Oxidative)

Contract slowly, fatigue slowly, small diameter, and use aerobic respiration for ATP production.

Cardiac Muscle

Striated muscle with short, branched fibers connected via intercalated discs.

Smooth Muscle

Involuntary muscle found in blood vessels and organs, containing actin and myosin but no sarcomeres.

Motor Unit

A motor neuron and all of the muscle fibers it controls, contracting simultaneously.