Muscular system and basic muscle groups

The muscular system is one of the most important biological subsystems by which the body performs various movements.

It can be represented as a set of muscle fibers capable of contraction. Fibers connect to each other in bundles that form muscles as special organs, or they themselves enter internal organs. The mass of muscles is much higher than other organs: in some animals it is 50 percent of the total body weight, and in man it is 40 percent. The muscular system turns chemical energy into heat and mechanical energy.

Muscular Musculature

In vertebrates, muscular musculature is divided into the following groups:

• Somatic, which includes the interior and the muscle of the limbs. It includes skeletal muscles.
• Visceral (part of the internals). It is a smooth and cordial musculature.

The human muscular system

Skeletal muscles are arbitrary and striated. They attach to the bones and are cylindrical fibers 1-10 cm in length.

Each muscle fiber is an undifferentiated cytoplasm (sarcoplasm) with a large number of nuclei located along the periphery. Periphery includes differentiated cross-striated myofibrils. Surrounds the periphery of the transparent shell (sarcolemma), which includes collagen fibrils. A small group of fibers is surrounded by endomysia; Large muscle connections are bundles of fibers enclosed in internal intermiases; Each muscle is surrounded by an outer armpit. The muscles and connective tissues of each other continue and are linked together. The whole muscle is enclosed in a box called a fascia. The muscular system consists of muscles, each of which is connected to nerves and vessels and permeated by them.

Muscles help to maintain the balance of the body, carry out movement in space and vital movements of all parts of the body.

Smooth muscles are located in the walls of blood vessels and internal organs. The length of muscles of this species is 0.02-0.2 mm. They are devoid of striation, their shape resembles a spindle. Smooth muscle cells have an oval core in the center.

Smooth muscles contribute to the transport of what is contained in the hollow organs (food in the intestine, for example). They are involved in the regulation of pressure, the expansion and contraction of the pupil, and other movements in the body. For the contraction of smooth muscles, the autonomic nervous system responds.

The muscular system also includes the heart muscle, which is only in the heart walls. It is continually contracting all life, providing blood circulation through the vessels and nourishing the tissues and organs with the necessary substances.

Musculoskeletal system

The human body contains about 400 muscles of the striated muscles, which are contracted under the control of the central nervous system.

The musculoskeletal system includes muscles, bones, tendons, joints, ligaments and cartilages, which make up almost 75% of the body weight. This system gives the human body a certain form, allows it to stand and move around. The skeleton serves as a skeleton for organs and tissues, it also reliably protects important organs from damage. In the bones are accumulated such minerals as phosphorus and calcium. The interior of the bones is represented by the bone marrow, involved in the formation of all blood cells (erythrocytes, white blood cells and blood platelets).

With injuries and diseases of any part of the musculoskeletal system, the statics and dynamics of the whole organism are disrupted. In addition to the fact that the entire musculoskeletal system suffers, the internal organs also cease to function properly. For example, when one of the extremities is shortened, the spine is twisted, which causes deformation of the chest, as a result - the circulatory and respiratory organs suffer.