Chewing and mimic muscles: anatomy. Features of facial muscles

All people have bad and good days, happy and sad events, something happens that angers, offends, upsets or, on the contrary, leads to indescribable delight, causes fun and happiness. At such moments our face is just a book in which you can read all the feelings.

But why does this happen? What is there in the structure of the face that allows us to be so different, lively, interesting and multifaceted in expressing emotions? It turns out that it is the merit of different types of muscles. It's about them that we'll talk about in this article.

History of the study and discovery of muscle structures

For the first time, the presence of muscle in the human body was said back in antiquity. Egyptians, Romans, Persians, the Chinese mention in their books about these structures under the human skin. However, the description of the muscles as such is encountered much later. So, Leonardo da Vinci made a huge contribution to this. Of the 600-odd drawings on the human anatomy, which he left behind, most of it is dedicated to the muscles, their location on the body, structure, appearance. Also, the descriptions of muscles are found in the works of Andreas Vesalius.

The physiology of the work of muscles was studied by the following scientists of the eighteenth and twentieth centuries:

1. Luigi Galvani - discovered the phenomenon of electrical impulses in muscles and animal tissues.
2. Emile Dubois-Reymond - formulated a law reflecting the effect of current on excitable tissues
3. NE Vvedensky - described and established the optimum and pessimum of electric excitation in muscles
4. G. Helmholtz, J. Liebig, Wislitzenus, V. Ya. Danilevsky and others - studied in detail and described all the physiological features of the functioning of muscle tissue, including heat transfer during exercise and muscle nutrition.

At the present stage of development, practically all possible theoretical descriptions of any functional features of muscle fibers have already been formulated. Electrophysiology, biochemistry, anatomy and other sciences contributed to the accumulation of an extensive knowledge base in this field, so important for medicine.

The number and definition of a person's muscles

In total there are about 640 muscles in the human body, each of which fulfills its special function. Anatomy of the muscles is a set of complex structural parts.

Muscles (or muscles) are human organs, which is a set of muscle fibers (cells of elongated shape) that have a smooth or cross-striated pattern. They are held together by the connective tissue of a loose structure. In the human body form a whole system of skeletal muscles (striated tissue) and lining many organs and vessels (smooth tissues).

Classification

According to the functions performed, the muscles are divided into the following groups:

1. Offtake.
2. Leading.
3. Supinators.
4. Sphincters.
5. Dilators.
6. Rotators.
7. Flexors.
8. Extensors.
9. Contrasting.
10. Pronators.

There is also a classification of muscles according to their location in the human body. So, they distinguish:

• Muscles of the trunk (superficial and deep);
• Muscles of the extremities;
• Muscles of the head (mimic and chewing).

The form

According to this feature, there are 7 main groups of muscles, each group is localized and functional in a certain part of the body of people.

1. Spindle-shaped.
2. Square.
3. Flat.
4. Straight lines.
5. Triangular.
6. Cirrhous.
7. Circular.

Anatomy of the muscles

Each muscle has approximately the same plan of the internal structure: outside it is covered with epimisis - a special substance-shell, produced by a connective tissue. From the inside it is a set of muscle beams of different orders, which are combined due to endomysia - connective tissue. At the same time, a row of blood vessels and capillaries is suited to each muscle for sufficient oxygen supply during operation. The veins take the decay products and carbon dioxide. Nerves that pierce the fibers provide conductivity, excitability and a quick and qualitative response (work).

The muscle cells themselves have several nuclei, since during active work they are able to produce thermal energy due to numerous mitochondria. Their ability to contract muscle is due to special proteins: actin and myosin. They provide this function, causing the contraction of the myofibril - the contractile part of the muscle fiber.

The most important functions of muscle fibers are contractility and excitability, provided by the joint interaction of nerves and protein structures and controlled by the central nervous system (brain and spinal cord).

Muscles of the head

This group includes several basic types. The main are:

• Muscles of the face (mimic muscles) - are responsible for facial expressions, external manifestations of emotions;
• Chewing - perform the same function.

In addition to them, the muscles are distinguished:

• Eyeball;
• Auditory ossicles;
• Language;
• The sky;
• Throat.

The peculiarity of the structure of all the muscles of the head, except for the cheek, consists in the absence of fascia - a special "handbag" in which all the muscles are located and which is attached directly to the bones. Therefore, the overwhelming part of them by one side is attached to the bones, and the other - freely flows directly into the skin, tightly interwoven with it in a single structure.

Mimic facial muscles: types

The most interesting and clearly showing their work externally are just the facial muscles. Thanks to the performed function, that is, the ability to form a facial expression of a person, they got their name - mimic muscles.

There are many of them. After all, it is only necessary to recall how bizarre and varied expressions of our emotions can be, in order to understand that it is impossible to cope with such work alone or alone. Therefore, the facial muscles act as whole groups, and there are only 4 of them:

1. Forming the cranial vault.
2. Forming the circumference of the mouth.
3. Shingles of the nose.
4. Forming a circle of eyes.

Let's consider each group in more detail.

Muscles of the cranial vault

The facial muscles of the head, which form the cranial vault, are represented by the occipital-frontal, attached to the tendon helmet. The helmet itself is a tendon that conventionally divides the muscle into two parts: the occipital and frontal. The main function that these facial muscles perform is the formation of transverse folds of the skin on the forehead of a person.

This group includes the anterior and posterior ear muscles. Their main action is to enable the auricle to move up, down, forward and back.

The transverse lining muscle is part of the structures of the cranial vault. The main function is the movement of the skin on the back of the head.

The muscles that form the circumference of the eye

These are the most expressive facial muscles of the face. Their anatomy does not imply the presence of a fascia, but the shape of such structures is different.

1. The circular muscle completely surrounds the eyeball in a circle under the skin. It consists of three main parts: ophthalmic, eyelid and tear. Action - opening and closing of eyes, control of teardrop, lowering of eyebrows, smoothing of folds on forehead.
2. Mimic muscles, wrinkling eyebrows, are attached from the frontal bone to the skin of the eyebrows. Function: the formation of longitudinal folds on the bridge of the nose.
3. The muscles of the proud - the name itself speaks of meaning - forms the transverse folds at the base of the nose, giving the face an expression of pride and inaccessibility.

Such mimic facial muscles allow people to express their emotions only with their eyes, eyes and skin around them. Much can be said without words due to such features of the structure of the human body.

Muscles forming the circumference of the mouth

No less important are the other facial muscles of the face. The anatomy of this group of muscles is represented by a circular structure surrounding the oral opening. There are several basic muscles that are antagonistic towards each other. This means that some of them expand the mouth slit, and the other, on the contrary, narrows.

1. Muscle of the mouth, called circular. Action: narrowing the mouth and lips moving forward.
2. Cheek muscles (large and small). Functions: allow the corner of the mouth to move up, down and to the side.
3. The features of facial muscles of the mouth are that they allow it to move. So, for example, in the base of the upper jaw there is a muscle that allows lifting the upper lip. Nearby is located one that raises and the wing of the nose.
4. The cheek muscle. Value: pulls the corner of the mouth to the side, with simultaneous contraction from both sides allows to draw the inner surface of the cheeks to the jaw.
5. The muscle of laughter. Action: allows the corners of the mouth to stretch laterally.
6. Two chin muscles. The features of facial muscles of this type consist in the fact that one of them is unstable, it can be reduced. Function: provide movement of the chin's skin, and also pull the lower lip forward.
7. Muscle, lowering the lower lip. The meaning is according to the name.

These are all the basic mouth mimic muscles of the face, the anatomy of which allows a person to smile, talk, express joy and discontent, move his mouth.

Muscles surrounding the nose

This group includes only two main muscles:

• The nasal muscle is composed of the inner and outer parts. Action: provide movement of nostrils and nose;
• The muscle, lowering the septum of the nose down.

Thus, in the circumference of the nose there are only two facial muscles. Their anatomy is no different from the others discussed above. In general, the aforementioned groups of muscles of the eye, mouth, nose and cranial vault are the main components of facial expression. Thanks to the presence of these muscles, people manage to transmit a range of feelings, communicate with each other even without words and support the phrases with the necessary visual expression.

Mimic muscles include very important structures that are also responsible for the formation of wrinkles during the aging process. That is why all centers involved in plastic surgery and similar procedures invite highly qualified specialists who know the anatomy of muscles to work.

Chewing muscles: varieties

Mimic and chewing muscles are the main components of the face and head. If 17 different structures belong to the first, then to the second group - only 4. However, these four chewing muscles play an important role in the life of a person, as well as in maintaining a beautiful young face oval. Let us consider which structures belong to them.

1. Chewing - the strongest, trained by a man during a meal, a muscle. It is located in two parts: deep and shallow. It starts from the zygomatic arch and attaches to the muscles of the lower jaw.
2. The temporal - starts from the appendage of the temporal bone and stretches to the lower jaw.
3. Pterygoid lateral - consists of two parts: the upper and lower head. It starts from the area of the sphenoid bone and ends in the muscles of the lower jaw, forming a complex interlacing with them.
4. The pterygoid medial is also located from the sphenoid bone to the lower jaw.

All these muscles are united by a commonness of the functions performed, which we now consider.

Functions

Naturally, since the muscles belong to the group of chewing, then their action will be corresponding: providing a versatile movement of the jaw:

• Chewing - the lower jaw lifts and pushes forward.
• Medial - provides lateral and other movements of the lower jaw.
• Lateral - has similar functions with the medial.
• The temporal is the main assistant in the masticatory movements. Pulls back the forward lower jaw, and also allows it to rise upward until it closes from the upper jaw.

In addition, it is the temporal muscle that gives the person a tired, tired and sagging appearance. If you are in a state of nervous tension, acute stress and stress for a long time, your body will lose weight, and the person takes the corresponding expression. This is due to the fact that the temporal muscle is thinned and, tightened by the skin of the face, visually changes its relief.

Thus, it can be concluded that the mimic and chewing muscles are the designers of our face, allowing to build in any expressions, perform various movements and change various grimaces. And they also allow you to chew, which is undoubtedly one of the most important life processes of most living beings, including humans.