Muscle Tissue

A collection of vocabulary flashcards about muscle tissue and its characteristics, structure, and functions.

Skeletal Muscle

Type of muscle attached to bones, enabling body movement.

Cardiac Muscle

Type of muscle found in the heart wall, responsible for pumping blood.

Smooth Muscle

Type of muscle found in visceral organs and blood vessels, controlling involuntary actions.

Excitability

The ability of muscle tissue to respond to stimuli, such as neural input.

Contractility

The ability of muscle fibers to shorten or contract when stimulated.

Elasticity

The ability of muscle fibers to return to their original length after contraction.

Extensibility

The ability of muscle fibers to be stretched beyond their relaxed length.

Epimysium

Connective tissue that surrounds the entire muscle.

Perimysium

Connective tissue that surrounds individual fascicles within a muscle.

Endomysium

The innermost layer of connective tissue that surrounds each muscle fiber.

Sarcoplasm

The cytoplasm of a muscle cell, containing myofibrils and other organelles.

Sarcoplasmic Reticulum

Network of tubules that stores and releases calcium ions for muscle contraction.

T tubules

Protrusions of the sarcolemma that spread excitation from the neuromuscular junction into the muscle cell.

Myofibrils

Cylindrical structures within muscle fibers that contain myofilaments and contract to cause movement.

Myofilaments

Thin and thick protein filaments within myofibrils, responsible for muscle contraction.

Sarcomere

The structural and functional unit of muscle, defined by the region between two Z discs.

Sliding Filament Theory

Theory explaining muscle contraction as the sliding of actin over myosin within sarcomeres.

Neuromuscular Junction

The synapse where a motor neuron communicates with a muscle fiber.

Motor Unit

A motor neuron and all the muscle fibers it controls.

All-or-None Principle

The principle that a muscle fiber contracts completely or not at all.