How the muscles work in different exercises. The most complete visual information!
Muscles or muscles (from the Latin. Musculus - muscle (mus - mouse, little mouse)) - organs of the body of animals and humans, consisting of elastic, elastic muscle tissue that can contract under the influence of nerve impulses. Designed to perform various actions: body movement, reduction of the vocal cords, breathing.
Muscles allow you to move parts of the body and express thoughts and feelings in action. A person performs any movements - from such simple ones as blinking or smiling, to subtle and energetic, which we see in jewelers or athletes - thanks to the ability of muscle tissue to contract. Not only mobility of an organism, but also the functioning of all physiological processes depends on the correct functioning of muscles consisting of three main groups. And the work of all muscle tissue is controlled by the nervous system, which ensures their connection with the brain and spinal cord and regulates the conversion of chemical energy into mechanical energy.
In the human body, there are 640 muscles (depending on the method of calculating the differentiated muscle groups, their total number is from 639 to 850). The smallest are attached to the smallest bones, located in the ear. The largest - large gluteal muscles, they set in motion the legs. The strongest muscles are calf and chewing. The longest muscle of the person, the tailor, starts from the anterior upper spine of the wing of the Ilium (anterior-upper parts of the pelvic bone), spirally spreads anteriorly through the thigh and is attached by a tendon to the tibial tuberosity (upper parts of the lower leg).
The shape of the muscles is very diverse. The most common spindle-shaped muscles characteristic of the limbs, and wide muscles - they form the walls of the body. If the muscles have a common tendon, and there are two or more heads, then they are called two, three, or four-headed. Muscles and skeleton determine the shape of the human body. An active lifestyle, balanced nutrition and sports contribute to the development of muscles and reduce the amount of adipose tissue.
All this knowledge will be an important milestone on the way to building a beautiful body relief. Well, we are starting ...
Why do muscles grow?
It is known that due to the reduction of muscle fibers (more precisely, the myofibrils, which are responsible for it), the muscle itself is also reduced. The signal comes from the motor neurons of the spinal cord and goes along the axon and, forking, joins the muscle fibers. Myofibrils are composed of sarcomeres, which contain the protein myosin and actin (see image).
During the contraction of the muscle fiber, the bands of myosin draw actin threads to each other with the help of processes. The processes contain an ATP molecule, and they receive a signal for contraction (1). Then, under the action of the enzyme ATP on the process turns into ADP + F (2).
The process of myosin connects to the actin filament (3) and the actin filaments are pulled together to each other, due to the release of energy from the ATP molecule (4). However, the process is still linked to the actin filament, but without energy molecules. Then a new ATP molecule enters, and the process of myosin is already detached from the actin filament (5).
This is exactly what the process of muscle contraction looks like. Understanding the process of muscle contraction will make it easier to understand how muscles grow. So, in every cell there is a nucleus (the muscle fiber contains many nuclei), which contains DNA - information about the structure of the cell. In the case of muscle damage (their microtraumas under heavy load), thanks to this “memory disk”, a new tissue is built at the injury site. Moreover, the recovery process takes place in supercompensation mode, i.e. add-on material is added above injured structures.
Microtraumas in the muscles occur when the necessary ATP molecule is missing to detach the processes of myosin from the actin filaments. It turns out that microtrauma is nothing more than tearing off the aforementioned process. After such a separation (there are quite a lot of them, for there are thousands of processes in the muscle):
- The body restores its original structure, recreating the damaged processes;
- Thanks to a good defense response (and survival mechanism) to stress, the body is seeking funds to build additional processes of myosin. Thus, the next time such a burdening weight is hardly “shocking”, which means that the working weight will increase and the muscle will increase in volume.
Muscle and muscle groups
And for a start, a few words about the very concept - muscle atlas. This is a kind of generalized picture of muscle groups belonging to all parts of the human body. In accordance with the latter, the muscles are divided into:
- Back muscles
- Chest muscles
- Muscles of the shoulder girdle
- Arm muscles
- Abdominal muscles
- Leg muscles
In each part of the body, their muscle groups are distinguished - a complex consisting of several muscles performing the same motor function. Very often, with the same movement, almost all the muscles from the same muscle group are involved in the exercises, so they operate with the names of the muscle groups. Although, the latter can sometimes be omitted and replaced with the name of the largest muscle of this group, for example, the front surface of the thigh is often “called” with quadriceps (quadriceps muscle).
- A man has over 680 different muscles
- The muscles of the jaws develop a force of 80 kg.
- The fastest muscle - the muscle of the century, responsible for blinking
- The largest muscle is the gluteus maximus (for some, it is just a very large
- The smallest muscle, the stirrup (3 mm), regulates the sensitivity of the ear to the sound
- The strongest muscle is the gastrocnemius, it can hold weight up to 150 kg.
- The functionality of the thumb muscles is 75% of the functionality of all the muscles of the hand.