test 3 review

Histology

The study of the microscopic structure of tissues.

Smooth Muscle

Type of muscle characterized by non-striated, cigar-shaped nuclei, found in hollow organs.

Cardiac Muscle

Type of muscle found only in the heart, has striations and intercalated discs.

Skeletal Muscle

Type of muscle under voluntary control with striations, responsible for body movement.

Z Disc

The boundary structure of a sarcomere where actin filaments attach.

Sarcomere

The structural and functional unit of a muscle, from one Z disc to the next.

Neuromuscular Junction

The synapse between a motor neuron and a muscle fiber.

Axon

The long, slender projection of a neuron that conducts electrical impulses away from the neuron's cell body.

Acetylcholine

A neurotransmitter released at the neuromuscular junction that stimulates muscle contraction.

Sarcoplasmic Reticulum

An organelle that stores calcium ions in muscle cells.

Myofilament

The protein filaments responsible for muscle contraction, primarily actin and myosin.

Power Stroke

The phase of muscle contraction where myosin heads pull actin filaments toward the center of the sarcomere.

M line

The line that runs down the center of a sarcomere, anchoring the thick filaments.

I Band

The light band of a sarcomere that contains only thin filaments.

A Band

The dark band of a sarcomere that contains thick filaments and overlapping thin filaments.

Schwann Cells

Type of glial cells that insulate axons with myelin in the peripheral nervous system.

Sodium Ion

The ion that enters a muscle cell during depolarization to initiate contraction.

Neurotransmitter

Chemicals that transmit signals across a synapse from one neuron to another.

Myosin

The thick filament protein that interacts with actin to cause muscle contraction.

Actin

The thin filament protein that, when bound to myosin, facilitates muscle contraction.

Excitation-Contraction Coupling

The process of converting an electrical stimulus from a neuron to a mechanical response in muscle fibers.

Triad

The structure formed by a T-tubule and two terminal cisternae in muscle cells.

Satellite Cells

Muscle stem cells that are involved in the repair and regeneration of muscle tissue.