Muscle Tissue Types and Characteristics

Voluntary muscle tissue responsible for movement, characterized by striations, multiple nuclei, and cylindrical shape.

Involuntary muscle tissue that forms the walls of internal organs and regulates their passageways by controlling the lumen size.

Involuntary muscle tissue that forms the heart's walls; essential for pumping blood.

Individual muscle cell; a long, cylindrical cell formed by the fusion of multiple embryonic cells.

Plasma membrane of a muscle fiber.

Threadlike structures within muscle fibers, composed of smaller myofilaments.

The protein filaments (actin and myosin) that make up myofibrils; the functional units of contraction.

The functional unit of muscle contraction, composed of overlapping actin and myosin filaments.

Connective tissue structures that connect muscles to bones or other muscles.

The more movable attachment point of a muscle.

The fixed or less movable attachment point of a muscle.

Muscle primarily responsible for a particular movement.

Muscle that opposes or reverses a movement.

Muscle that assists the prime mover in a movement, or reduces unwanted moments.

Muscles that span over two or more joints

Synergist Stabilizes the origin of the agonist muscles during multi-joint movements.

Adding up of muscle contractions to create stronger overall force.

A sustained, maximum muscle contraction.

Muscle weakness due to insufficient energy for further contraction.

The delay between stimulation and muscle contraction

Converting chemical energy into mechanical energy for movement.

Muscle fibers either fully contract or don't contract at all; the whole muscle can vary in strength of contraction depending on activated fibers.

A nerve impulse that triggers muscle contraction, causing a release of a chemical messenger.

A chemical messenger released at a nerve-muscle junction that initiates muscle contraction.

The minimum stimulus needed to cause a muscle fiber to contract.

A stimulus that is not strong enough to cause a muscle fiber to contract.

Muscles that move the forearm, hand, and fingers are classified into three groups based on their location and functions.

Muscles originating from the axial skeleton or shoulder girdle, often considered part of the trunk.

Muscle tissue temporarily becomes more permeable to sodium ions, which enter the muscle cell when stimulated.

A single, brief contraction of a muscle; has latent, contraction and relaxation phases.

Repeated stimuli lead to stronger muscle contractions over time, due to heat and calcium increase.

Muscle contractions build on each other if stimuli occur before full relaxation.

Sustained muscle contraction—no relaxation—from rapidly repeated stimuli.

Inability of a muscle to contract due to energy depletion or waste product accumulation.

The smallest stimulus strong enough to cause all muscle fibers to contract.

The stronger the contraction needed, the more motor units the brain activates.

Graphical representation of a single muscle contraction showing latent, contraction and relaxation phases.