Allow a person to move, speak, and chew. They control heartbeat, breathing, and digestion. Other seemingly unrelated functions, including temperature regulation and vision, also rely on the muscular system

Each sarcomere is composed of two main protein filaments—actin and myosin—which are the active structures responsible for muscular contraction

A protein that converts chemical energy in the form of ATP to mechanical energy, thus generating force and movement

The function of the myofibril is to perform muscle contraction via the sliding-filament model.

Allows a muscle to contract and move powerfully while maintaining its structural integrity

Myofilaments are key molecular regulators of the contraction. Indeed, thick-thin filament interactions (via the formation of myosin cross-bridges) lead to force production and motion

Muscle contraction, cell motility, cell division and cytokinesis, vesicle and organelle movement, cell signaling, and the establishment and maintenance of cell junctions and cell shape

They help to control the physical forces within the body. When grouped together, they can facilitate organized movement of your limbs and tissues

The component of the sarcomere that appears lighter because it contains only thin filaments. Allow more light to pass through them

Giving elastic stabilization of relative positions of myosin and actin filaments

Dark region of striation, which contains thick filaments. Includes the H zone which is slightly darker than the rest of the A band

the cytoplasm of a muscle fibre. It is a water solution containing ATP and phosphagens, as well as the enzymes and intermediate and product molecules involved in many metabolic reactions.

It acts as a barrier between the extracellular and intracellular compartments, defining the individual muscle fiber from its surroundings

in the H zone, the filaments consist only of the thick filament. The H zone becomes smaller as the muscle contracts and the sarcomere shortens.

These proteins are thought to be involved in anchoring the thick filaments of the sarcomere (myosin) to other filaments, namely titin, stabilizing and aligning the structure.

Their role is to maintain the SR calcium store under the tight control of membrane depolarization via the voltage sensor channel DHPR

the basic contractile unit of muscle fiber. Each sarcomere is composed of two main protein filaments—actin and myosin—which are the active structures responsible for muscular contraction.

a regulator of Ca2+ storage and release homeostasis during and after muscle contraction

Perimysium is a sheath of connective tissue that groups muscle fibers into bundles (anywhere between 10 and 100 or more) or fascicles.

the key element that separates single muscle fibres from one another. It allows their autonomous gliding during muscle contraction.

An actin-binding protein which can bind up to 200 actin molecules.

a protein involved in skeletal muscle contraction and that wraps around actin and prevents myosin from grabbing it.

a calcium-regulatory protein for the calcium regulation of contractile function in skeletal and cardiac muscles

dystrophin is part of a group of proteins (a protein complex) that work together to strengthen muscle fibers and protect them from injury as muscles contract and relax.

the N-terminal extremity of the catalytic domain, where there is a glycine-rich stretch of residues in the vicinity of a lysine residue. It is this lysine residue that has been shown to be involved in ATP binding.