Muscles: types of muscles, functions, appointment

A Little less than half the weight of the human body falls on the muscles. Types of muscle are divided according to purpose, functions, subordination of the nervous system, the structure of the fibers. They are indispensable to movement in the surrounding space, maintaining the normal processes of life and the constancy of the internal environment.

Musculoskeletal system

The Skeleton and muscles make up the skeleton of a man. Bones play a role of supporting structures. Skeletal muscles through connective tissue attached. They, unlike bone, is elastic and can be deformed.

Main functions - contraction and relaxation – allowed to move to man in space. Skeletal muscles are responsible for this process, works on the principle of levers. The passive part of the muscle (tendon) attaches to the bone at the optimum point to perform its work. The other part is connected with the paired area of the skeleton.

In place of articulation of the bones is a joint, that is, the connection is movable. While reducing the muscle force transmitted via the tendons will cause the bones in motion.

Muscular system

The Human body is segmented. Muscle (types of muscles shown in the photo above) are not out, they are divided into departments. For a concerted effort need control. When moving the limb is not just reducing a specific muscle. At the same time its antagonist relaxes. In a reverse process of function change: the flexor relaxes and the extensor returns a body part to its original position.

The coordination of skeletal muscles controlled by the brain. This process to some extent subject to human consciousness. And although the team on the basic moves are not given in a literal sense, they are still present in the intentions, and the brain them instantly transformerait in clear muscle signals.

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There is another system of muscles that the human will is completely subject to (involuntary). Basically it is the muscles of internal organs. Heart muscle generally allocated in a separate group. Reduction unable to control and in normal conditions does not notice. The function of the muscles of the stomach, bladder, intestines, walls of blood vessels differ. But their main task – the maintaining in good shape the particular body and to allow the fulfilment of essential functions.

Muscle: types of muscles

Classification is made according to several factors. The main division is due to a common destination. Isolated skeletal muscles and internal organs. Arbitrarily subordinates the muscles have a substantially transversely directed fibers, and the involuntary (internal) – smooth.

Depending on localization shared by the muscles of the head, limbs, torso. What kind of work they perform, among them determine the flexors and extensors. By occupation distinguish among muscle synergists, that is performing similar functions, and antagonists, acting in opposition. In form they may be: short and fat, long and thin. The broadest muscle belong to the flat muscles of the back. They are responsible for pulling the shoulder to the torso and abduction hands back, to the axis of the spine.

If the muscle while reducing the limb closer to the body, it is defined as leading. In the opposite case we say about the deferent role. If produce rotation of body parts (head, forearm, shoulder), their klassificeret as torque.

There is a division depending on the number of large bundles of fibers: biceps (biceps), triceps (extensor muscle of the hand), the quadriceps of the thigh. There are four composite of this muscle (the types of muscles: direct, lateral, medial, intermediate). The biggest – diaphragm, muscles of the buttocks, legs, and back. The smallest is in the ear. The strongest lower leg (calf) and chewing on his head.

Structure

Muscle tissue in the human body consists of cells. They have an elongated shape and capable of reducing due to the presence of special organelles (of microfilaments).

There are two types of fibers: white and red. This classification is relative. But the difference can be understood on the example of chicken meat (breast and drumstick). The first is white. Breasts in chickens is not as often as the tibia. Wings she waves rare, but they are capable of sudden burst of activity, giving the opportunity to rise into the air.

On the other hand, on my feet the whole life passes. Their fabrics can work for a long time, but is not capable of such a sharp burst of activity. The calf muscles in chickens densely permeated by a network of capillaries (from that color) because they need more power (constant and sufficient) for the maintenance of tone.

On a similar principle to construct muscles in humans. There is evidence that the average person white cloth and the red is in a ratio of 4/6. In athletes-sprinters there is another picture. They have fast white muscles are overweight. This is partly achieved by training, but not every person is able to transform.

Fibre Bundles

Skeletal musculature is designed for speed reductions. Cells their tissues relatively large, elongated and multinucleated (up to 100 or more). Ifto examine the slice under a microscope, it looks like striated alternating stripes of light and dark colors (striated). Tissue smooth muscle is composed of mononuclear cells. They are more uniform and not as elongated.

Skeletal muscles collected from bundles first (thinnest), the second (larger), etc. order. The method of placement in relation to the axis of the spine is divided straight muscles (rectus muscle press), slash (belly: inner and outer) and transverse (perpendicular to the vertical axis – the transverse muscle of the chest).

Depending on the location of the tendons around them are divided into parallel (axis) and circular (the mouth, the sphincter of the rectum, vagina).

The Tissue of the heart muscle a special. It consists of two-nuclear cells (cardiomyocytes). They are intertwined, so that together, connecting the cytoplasm. The peculiarity of the heart muscle – ability to work rhythmically and constantly.

Work

Even with the apparent relaxed state of the muscles still ready for immediate reduction. This condition is called tonus. Nerve impulses constantly coming in all the organs from the brain. In a relaxed state number decreases, but they are sufficient for information exchange. Without such a control would not be able to keep the body in balance and stable position.

Source of energy for working muscles is adenosine triphosphate (ATP). It is the result of a difficult cycle for the breakdown of glycogen. The nutrition of the cells is carried with blood flow. From this it follows that all the major muscles must be densely braided capillaries, arteries and veins.

To Run all the time they needed to rest. If this be neglected, the reduced efficiency that shows impaired conduction of impulses and response to neural stimulation. Under intense loads accumulate products of metabolism, which prevents uniform distribution of the impulses.

Localization

The human Body is built on the principle of bilateral symmetry, so all the major muscles paired or consist of two halves. Located on the head are involved in the facial cuts, giving the opportunity to Express emotions (joy, sorrow, fear, pleasure). Another important feature – the work of the oral apparatus (chewing, swallowing). They also provide eye (movement of the eyeball, blinking of the eyelids).

The neck muscles raises and lowers the head, turns it and supports in the axis of the spine. On the torso distinguish the front and back. Divided into the upper section (work the shoulder girdle); the thoracic (breathing); abdominal (belly tone). The largest part of the back cover of the broadest muscle. In addition to participating in the extension of the hands and circular movements of the shoulders they form the back, below the ribs, the frame body, covering the kidneys and liver. Active during swimming, working with a deep breath, lifting the bottom edge.

The Front, top part of the coverage leading large pectoral muscles. In the abdominal area is deeply buried and thin transverse muscle. It opposes gravity and supports the constancy of the internal environment of the abdominal cavity. Along with pressure ensures the plane's belly.

At the site of the junction of the trunk and lower extremities is important gluteus Maximus muscle (big, medium, small). On the thigh can distinguish preperitoneal, double-headed, short, long and great leading. Lower leg – the calf, the soleus. And stop – the flexors and extensors of the fingers.

Role in the body

Without proper activity of muscles in humans can atrophy. Seen that at minimum load cell are updated every one to two weeks. In sports it happens more often. The growth of muscle tissue with loads with additional weight is due to the fact that part of the muscle fibers torn. The body tends to regenerate, grow new cells, when updated. This is accompanied by an increase in their volume and mass.

In addition to the implementation of cardiac activity, maintain body shape, provide vertical position and movement of muscles makes it possible and a number of other equally important processes: speech (larynx and tongue), breathing (diaphragm), digestion (esophagus, the tone of the stomach, intestine). Ensure the excretion of metabolic products (the bladder, the sphincter of the rectum).

If the activity of the involuntary muscles of the person is not able to control arbitrary (core muscles) maybe even coaching. Well, a healthy lifestyle and keeping the body in good physical shape, as you know, is the key to good health and emotional balance.

Now you know what is the role of the body's muscles. The types of muscle differ in their structure and functions.