Definition of Muscle Fiber

Muscles are made up of the union of a group of cells that constitute contractile units whose function is to provide it with its ability to movement, each of these units or cells is known as muscle fiber.

From muscle fiber to muscle

The muscle fibers have the shape of an elongated filament, they gather in groups that are arranged in a parallel way forming sheets, each group It contains blood vessels and is covered by connective tissue forming the muscle bundles that join together to give rise to the muscle.

The connective tissue is formed mainly by collagen, this has the function of creating compartments independent and also provide the spaces through which the blood vessels that will carry so much oxygen like nutrients into the muscle cells and will bring waste substances such as carbon dioxide back into the general circulation. carbon (CO2) as well as the products resulting from muscle activity, predominantly acid lactic.

The importance of the muscle being made up of compartments lies in the fact that this allows movement to be carried out only in part of it and not in its entirety. In the case of large muscles such as the deltoid, which is located in the shoulder, the contraction of its anterior part helps to bring the shoulder forward, while when its back is contracted the shoulder moves more towards behind.

Muscle fiber function

Muscle fibers are capable of contracting, shortening their length, this phenomenon is what allows movement in voluntary muscles or striated muscle, which are what make up the muscular system.

At the level of heart a different type of muscle fiber is present that gives rise to the heart muscle, in this the contraction of the muscle fibers allows the heartbeat necessary to propel the blood through the circulatory system.

The viscera contain other types of muscle fibers that originate the smooth muscle, the contraction of these fibers is an involuntary process and allows movements to occur that increase or decrease the diameter of the hollow viscera and the different ducts, favoring or slowing down the transit of substances through it. An example of this occurs during the digestion, the muscle fibers are shortened to give rise to peristaltic movements that favor intestinal transit with what food passes from the mouth to the esophagus, to the stomach, to the small intestine and finally to the colon, in this process many ducts intervene facilitating the arrival of substances necessary in this process such as bile from the liver and enzymes originating in the pancreas.

Red and white muscle fibers

Muscle fibers have variations that allow them to adapt to the needs of each type of muscle. Some fibers are rich in a compound called myoglobin that makes them darker, these fibers contract from slow form, another type of fibers are called white fibers, they have a larger diameter but contain less myoglobin.

The white muscle fibers they have a metabolism anaerobic, they are designed to execute fast and powerful movements for a short period of time, the red muscle fibers have a higher metabolism, require the presence of oxygen so they are aerobic, they contribute to executing slower movements that require greater resistance and force.

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