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 musclefibers capable of contraction. Fibers are connected 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 that of 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 inside and the muscle of the limbs. It includes skeletal muscles.
  • Visceral (part of the internals). It is smooth and cardiac musculature.

The human muscular system

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

Every muscle fiber isundifferentiated cytoplasm (sarcoplasm) with a large number of nuclei located along the periphery. The 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 maintain balance of the body, move in space and vital movements of all parts of the body.

Smooth muscles are located in the walls of blood vessels and internalbodies. 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 nucleus in the center.

Smooth muscles contribute to the transportation of that,that is contained in the hollow organs (food in the intestine, for example). They participate 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 heart muscle, which is only in the heart walls. It is continuously reduced throughout life, providing blood circulation through the vessels and nourishing the necessary substances with tissues and organs.

Musculoskeletal system

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

The musculoskeletal system includes muscles, bones,tendons, joints, ligaments and cartilage, accounting for almost 75% of the weight of a person. 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, leukocytes and blood platelets).

In case of injuries and diseases of any partthe musculoskeletal system is disturbed by the statics and dynamics of the whole organism. In addition to the fact that the entire locomotor apparatus 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 consequence - the circulatory and respiratory organs suffer.