The body of each person contains 650 muscles. Their specific weight can be a third of weight at women and to 45% at men. From all existing, muscle tissue not only is dominating as a part of an organism, but also differs in the variety. Different types of muscles allow the person to sit, stand, move, express with words and to crush food — without what it is difficult to present our life. Besides, they move blood on vessels and food to a stomach, ensure functioning of eyes and make many other various functions.
Evolution of muscles
There is no exact information at what moment muscles appeared. For the first time in evolution they are observed at flat and roundworms. At these simple organisms the muscles are presented by a muscular bag with muscle fibers. More complex structure of muscles is observed at mollusks, arthropods and chordates. Most strongly I the system of muscles am developed at vertebrata. Their muscle bulk reaches a half of body weight, it provides the main functions of activity. Human muscles are considered top of development.As muscles work
The structure of any muscle represents set of cages which work in the uniform party and carry the name of a muscular bunch. Each such bunch is presented by the cages reaching in length of 20 centimeters, the received names of fiber. The cell of smooth muscles reminds a spindle, at cross-striped it has oblong shape.
Action of muscles is directly connected with energy allocation. Its part disperses on an organism and guarantees stable temperature about 37 degrees. In a quiet condition of a muscle give up to 16% of heat, muscles work with approach of loading more actively. Therefore in especially cold weather of people shivers and does not freeze.
Considerable part of living organisms without muscular function cannot exist. They put joints in action, and carry out dozens more of various tasks. Their work is constructed on three main properties: excitabilities, conductivity and sokratimost, more precisely, than their alternation.
- The excitability is a response to action of an irritant, most often the external irritant acts as it. At this moment in muscles the metabolism changes.
- The conductivity is a property which is possessed by muscles, and it consists in ability to transfer a nervous impulse. It arises after action of an irritant to back and to a brain, and then, on the same way, comes back.
- Sokratimost — action of muscles on the irritating factor. Fiber becomes shorter and changes the tone, that is tension.Classification
List of names of human muscles quite impressive. There are several types of their association on various signs. Today it is possible to tell that there is no uniform standard classification, but if to consider division on different signs, then it looks as follows:
Form and length
From placement and how muscle fibers to a tendon fasten, allocate three following views. Muscles of short length give work to small sites of a musculoskeletal system. They are usually located very deeply, for example, intervertebral muscles of a back. Long muscles give the movement to extremities, providing them the maximum amplitude. Among them: a biceps, a triceps, a quadriceps, they are located on the lower and upper extremities. Wide are located on a back, a stomach and a breast and carry out sokratitelny movements.
Different functions
Muscles sgibatel and razgibatel work alternately when they are reduced, others relax, then on the contrary. For example, the biceps bends a hand, and the triceps — unbends. The taking-away and bringing muscles are opposite on functionality. Some give the chance to make circular motions of a trunk, that is to move inside and outside.
In relation to joints
It is known that muscles are connected to bones by means of tendons, they set them in motion. How muscles fasten, allocate one-articulate and multiarticulate muscles.
Bunches of muscles
Muscular bunches are divided into plumose which are incredibly similar to the structure of a feather of a bird. Since one end the bunches reliably fasten to a tendon, from another they disperse. Such building is inherent in strong muscles. Muscles with parallel bunches often call dexterous. Their task is to perform the most delicate work in connection with high endurance.Where muscles are located
Division of muscles of a human body into groups it is connected with their location, each part of a body has it the.
But very responsible the group located on the head and a neck is small. It is presented by chewing and mimic muscles. The first allow to crush food, the second — to talk.
- By means of muscles of the head and a neck the function of swallowing, chewing and a conversation is provided. With their help the eyeball turns by 180 degrees that allows to see everything around.
- Large muscles of a neck stabilize the head, allow it to bend and rotate.
- By means of facial muscles it is possible to express a mimicry emotions, muscles of a mouth and eye-sockets give a mimicry.
Muscles of a trunk are faced by the main task: to keep a body in vertical position. They help it to make various movements, and provide respiratory function. They represent a number of anatomic departments and are united in three big groups:
- A large number of muscles is located in a thorax. They allow to change the volume of a cage and help to make breath.
- Muscles of a stomach help a backbone to turn and bend, help to move to hands. Besides, they are involved in processes of an organism: movement of blood on vessels, breath, release of intestines and release of urine.
- Back muscles help to work to a backbone, a neck, the upper extremities and a thorax. The largest muscles on buttocks and hips.
- Muscles of extremities are responsible for bending of hands and legs, and muscles of the lower extremities also for function of a shin and coxofemoral joint.Types of muscle tissue
Except classification of types of muscles, there is a division depending on features of physiology.
1. Skeleton muscles
They make the most part of specific weight of muscles and are presented by longitudinally cross fabric. In it light and dark fibers mix up. Thanks to them the musculoskeletal device functions. This function is controlled by human consciousness, even when the person has a rest, some muscles continue the begun work and give the chance to keep the accepted pose. The smallest skeletal muscles provide a mimicry. When the person smiles, 17 types of muscles work and to take one step, 54 different muscles are involved.
2. Smooth muscles
This look formed muscles of the internals located in an abdominal cavity — intestines and a stomach, respiratory organs and vessels of blood. In them red and white fibers irregularly alternate. Their reductions not such fast as at skeleton muscles, and then they long remain in a condition of tension — in a tone. Their main difference is that work out of control of consciousness of the person and provide a vermicular movement. The example of smooth muscles can also be considered an eye. When muscles change a crystalline lens corner, the possibility of control of brightness and sharpness of the image appears.
3. Myocardium
Our heart works without rest. Per day it should pump over up to 7200 liters of blood. It pushes out liquid in an artery and at relaxation accepts it from veins. The cardiac muscle is called a myocardium, it only in this body. Work of heart depends on rhythm reductions, their frequency increases when the person performs hard work as it needs more oxygen.
Interesting facts
Surprising tiny muscle in a human body — stremenny. Its main objective consists in regulation of a certain pressure upon a stone in an inner ear. The most massive muscle — a gluteus. The most impressive length at a sartorial muscle. It reaches from a basin for tibia and bends a leg in a knee joint and coxofemoral. When the person clenches teeth, chewing muscles develop force more than 90 kilograms, and it means that it will keep this weight.
Scientific progress reached the medical industry and the anatomic sphere long ago. Scientists from Taiwan created artificial muscles. In them there are no rubbing parts, and they does not wear out at all. Therefore such muscles will be applied further in robotics.