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Movement of bodies, muscles and bones

The biceps muscle, and its location is the humerus, is connected from below to the radius bone of the forearm, by means of a tendon. When it contracted and shortened, the forearm was raised with it. In the circle is a picture of fibers how they come together to become a muscle.

One of the characteristics of the first animals is movement, and in the body there are special cells that are grouped together, and their primary purpose is to cause movement in the body.

This movement includes the movement of the heart, the movement of the chest when breathing, the movement of the hand when raising and lowering, the movement of the leg when walking and running, and the movement of the stomach and intestines when mixing food or pushing it forward little by little. There are many other movements like this.

- Types of muscles

There are three types of muscles:
The first type: Skeletal muscles that move the bones of the body’s skeleton. They are the muscles of the torso or limbs, from which human flesh is composed. They constitute about 40 percent of his body weight. Each muscle consists of a bundle of muscle cells, which are long cylindrical fibers, with a diameter between one-tenth and one-hundredth of a millimeter, and lengthening to about 40 millimeters. It works according to the will of the owner of the body. If he wishes, it works, and if he wishes, it remains silent. Most of these muscles have two ends connected to two bones, each to a bone, by a tendon.

The muscle contracts and shortens, thus pulling the moveable bone towards it, and you see in the picture the biceps muscle. It contracted, then shortened, and the two forearm bones were drawn to it.

Our discussion in this word is mainly about this type of muscle.

The second type of muscle is the cardiac muscle, which makes up the heart. It is the one that pumps blood into the heart by causing contraction and relaxation in an uninterrupted sequence, through which the blood continues its circulation in the body.

The third type of muscle is the muscle that they call smooth muscle, which is found in the wall of the body’s hollow internal organs such as the stomach, intestine, bladder, and blood vessels.

The heart muscles and smooth muscles are not subject to the will of the body’s owner. As for skeletal muscles, they are subject to the will of their owner, as we mentioned, through nerve signals coming from the brain.

- The movement of the body is nothing but tension

The muscles work and move by contracting, so they are
It works by pulling, not by pushing.
A person may demolish a wall and think that he has just demolished it
By pushing him, which he did. The geometry of the body requires groups of muscles to exert tension, which accumulates and becomes a push and pull against the wall.

- The strength of objects

It's muscle strength.
But we must know that muscles, like nerves, are formed in the newborn child, and they remain like this in his system throughout his life. It gains strength through work.

If you compared a muscle in the arm of a blacksmith with a muscle in the arm of a girl, you would find that the number of fibers was the same, but the growth differed, and thus the strength differed.

(There are three types of muscles in the human body: skeletal muscle, cardiac muscle, and smooth muscle)

The power that a man can reach, according to theoretical calculations, is 6 horsepower. But the power that the man actually achieved was 4.5 horsepower for a short period. A person can exert 6 times the power of a horse for a few minutes.

- Muscle contraction

And the influences that make muscle fibers. Four contractions:
Electrical, mechanical, thermal, and chemical. It's the first mover. It works through the central nervous system. A message of feeling that describes the situation and comes in response to what you do.

But the muscle works with chemical energy, which is converted into mechanical energy. However, the muscle only benefits 25 percent of its potential energy in its contraction from this transformation. The remaining 75% turns into heat. For this reason, the body heats up, maintaining a constant temperature that comes from the chemical reactions and transformations that take place in the body, including the conversion of chemical energy in the muscles into movement, contraction, and work.

This means that the efficiency of the muscle when it is powered by chemical energy amounts to only 25 percent of the amount that the body would be able to have, if the efficiency had reached its goal.
This is how the power of gasoline engines is like car engines, in which chemical energy is transformed into energy
Gasoline turns into kinetic energy, and the car only benefits 20% of this energy, and the rest is wasted heat.

- What happens when a muscle contracts?

This is recent, difficult research, in which chemistry was used in close and detailed ways. Electron microscopes were used to view the cells and what they produced while they were in their first original reactors.

Only a specialist chemist can benefit from it, especially in protein chemistry, if we go by what researchers have found.

But perhaps it is enough for us to say:
Fibres, with a diameter of about one-tenth of a millimeter, are visible under an electron microscope, which magnifies them tens of thousands of times. They are composed of yellow fibers, known as fibrils. Researchers have found that one row of these air conditioners is thicker than another row, and that...
Some of it goes into each other.

They learned that the thinner fibrils are made of the protein called actin, and the thicker fibrils are made of the protein called myosin.

It eventually became clear to them that muscle contraction occurs by bringing the ends of the actin fibrils closer together, and thus the muscle shortens. The illustration shows the location of the fibrils
Actinia from myosinia in 3 cases.

(a) The skeletal muscle is stretched and stretched
(b) The skeletal muscle is relaxed (c) The skeletal muscle is contracted.

- Cramp

It affects people in the legs, for example, especially the elderly at night. It may affect the swimmer in the water if he exerts great effort in the cold, and when the body loses a lot of its salt.

All of these muscle contractions and contractions may be caused by the nervous system that is not connected to the higher will in the brain.

These are symptoms whose causes are still hidden, as well as their treatment. But forced muscle contraction is the basis.

(An illustration depicts how a muscle contracts when it contracts. In Figure A, you find that the thin fibers (which are made of the protein called actin),
far apart. This means that the muscle is tense.
In Figure B, you find these fibers close together
Somewhat, the muscle is relaxed.
In Figure C, the white fibers converged evenly
It touched, and this means that the muscle has contracted and has reached the maximum shortening possible.)