Muscles – Skeletal Muscle 1/2

Flashcards covering key concepts related to skeletal muscle anatomy and contraction mechanisms.

Skeletal Muscle

Attached to skeleton, striated, multinucleated, fastest speeds of contraction, controlled by the somatic nervous system.

Cardiac Muscle

Muscle of the heart, striated, uninucleated, intermediate contraction speed, controlled by the autonomic nervous system.

Smooth Muscle

Muscle found in internal organs and vessels, smooth, uninucleated, slowest contraction speeds, regulated by the autonomic nervous system.

Excitation-Contraction Coupling

The process by which an action potential in a muscle fiber leads to muscle contraction.

Role of Calcium in Contraction

Calcium binds to troponin, allowing actin-myosin binding which leads to contraction.

Cross Bridge Cycle

The series of events that occur when myosin heads pull on actin filaments during muscle contraction.

Neuromuscular Junction

The site where a somatic motor neuron and a skeletal muscle fiber communicate.

Sarcomere

The basic contractile unit of a muscle fiber, composed of overlapping thick (myosin) and thin (actin) filaments.

T-tubules

Extensions of the sarcolemma that penetrate into the muscle fiber to facilitate the transmission of electrical impulses.

Sliding Filament Theory

The theory that describes muscle contraction as the sliding of actin filaments over myosin filaments.

Muscle Relaxation

The process that occurs when calcium is pumped back into the sarcoplasmic reticulum, allowing muscle fibers to return to their resting state.

Power Stroke

The action of myosin heads pulling actin filaments toward the center of the sarcomere during contraction.