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 is this happening? 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 this is a merit of different types of muscles. We will talk about them in this article.
History of the study and discovery of muscle structures
For the first time, the presence of muscles in the human body was spoken in antiquity. Egyptians, Romans, Persians, Chinese mention in their books about these structures that are under the skin of a person. However, descriptions of specific muscles as such are found much later. So, a huge contribution to this was made by Leonardo da Vinci. Of the 600-odd drawings on the human anatomy that he left behind, most are devoted to muscles, their location on the body, structure, and appearance. Also, muscle descriptions are found in the works of Andreas Vesalius.
The physiology of muscle work was studied by the following scientists of the XVIII-XX centuries:
- Luigi Galvani - discovered the phenomenon of electrical impulses in muscles and animal tissues.
- Emil Dubois-Ramon - formulated a law reflecting the effect of current on excitable tissues
- N.E. Vvedensky - described and established the optimum and pessimum of electrical excitation in muscles
- G. Helmholtz, Yu. Liebig, Wislicenus, 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, almost all possible theoretical descriptions of any functional features of muscle fibers have already been formulated. Electrophysiology, biochemistry, anatomy and other sciences have contributed to the accumulation of an extensive knowledge base in this area, which are so important for medicine.
The number and definition of human muscles
In total, there are about 640 muscles in the human body, each of which performs its own special function. Muscle anatomy is a combination of complex structural parts.
Muscles (or muscles) are human organs, which are a set of muscle fibers (elongated cells) that have a smooth or cross-striated pattern. They are kept together by means of connective tissue of a loose structure. In the human body they form a whole system of skeletal muscles (striated tissue) and line many organs and blood vessels (smooth tissues).
Classification
According to the functions performed, the muscles are divided into the following groups:
- Discharge.
- Leading.
- Arch support.
- Sphincters.
- Dilators.
- Rotators.
- Flexors.
- Extensors.
- Opposing
- Pronators.
There is also a classification of muscles by location in the human body. So, allocate:
- trunk muscles (superficial and deep);
- limb muscles
- muscles of the head (facial and chewing).
The form
On this basis, 7 main muscle groups are distinguished, with each group being localized and functional in a specific part of the body of people.
- Spindle-shaped.
- Square.
- Flat.
- Direct.
- Triangular.
- Cirrus.
- Circular.
Muscle anatomy
Each muscle has approximately the same plan of the internal structure: the outside is covered with epimisium - a special substance-shell produced by connective tissue. From the inside, it is a set of muscle bundles of various orders, which are combined due to endomysium - connective tissue. At the same time, a number of blood vessels and capillaries are suitable for each muscle to provide sufficient oxygen during operation. Veins take decay products and carbon dioxide. The nerves that pierce the fibers provide conductivity, excitability, and a quick and high-quality response (work).
Muscle cells themselves have several nuclei, since during active work they are capable of generating thermal energy due to numerous mitochondria. Muscles owe their abilities to contractions to special proteins: actin and myosin. They provide this function, causing contraction of myofibrils - 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 ones are:
- facial muscles (facial muscles) - are responsible for facial expressions, external manifestations of emotions;
- chewing - perform the function of the same name.
In addition to them, muscles are distinguished:
- eyeball;
- auditory ossicles;
- language
- the sky;
- pharynx.
The peculiarity of the structure of all the muscles of the head, except the buccal one, is 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 is attached to the bones on one side, and the other freely flows directly into the skin, tightly interwoven with it into a single structure.
Facial facial muscles: types
The most interesting and clearly manifesting their work externally are just the facial muscles. Due to the function performed, that is, the ability to shape a person’s facial expressions, they got their name - facial muscles.
There are quite a lot of them. After all, you just need to remember how bizarre and varied the expressions of our emotions can be to understand that you can’t cope with such work alone or together. Therefore, facial muscles act in whole groups, and there are 4 of them:
- Forming the arch of the skull.
- Forming the circumference of the mouth.
- Tinea nose.
- Forming eye circumference.
Let's consider each group in more detail.
Cranial vault muscles
The facial muscles of the head, forming the arch of the skull, are represented by the occipital-frontal, attached to the tendon helmet. The helmet itself is a tendon that conditionally divides the muscle into two parts: the occipital and frontal. The main function that such facial muscles of the head perform is the formation of transverse folds of skin on the human forehead.
The anterior and posterior auricular muscles belong to the same group. Their main action is to enable the auricle to move up, down, forward and backward.
The transverse outward 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.
Muscles forming the circumference of the eye
These are the most expressive facial muscles of the face. Their anatomy does not imply the presence of fascia, but the form of such structures is different.
- The circular muscle completely encircles the eyeball in a circle under the skin. It consists of three main parts: the orbital, secular, and lacrimal. Action - opening and closing eyes, controlling the tear, lowering the eyebrows, smoothing wrinkles on the forehead.
- The facial muscles that wrinkle the eyebrows are attached from the frontal bone to the skin of the eyebrows. Function: the formation of longitudinal folds on the nose.
- The proud muscle - the name itself speaks of its meaning - forms transverse folds at the base of the nose, giving the face an expression of pride and impregnability.
Such facial muscles of the face allow people to express their emotions only with a look, eyes and skin around them. A lot can be said without words due to such structural features 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 muscle group is represented by a circular structure surrounding the oral opening. There are several major muscles that are antagonists to each other. This means that part of them widens the mouth gap, and part, on the contrary, narrows.
- The muscle of the mouth, called circular. Action: narrowing of the mouth gap and forward movement of the lips.
- Zygomatic muscles (large and small). Functions: allow the corner of the mouth to move up, down and to the side.
- Features of the 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 you to lift the upper lip. Nearby is the one that raises the wing of the nose.
- Buccal muscle. Meaning: pulls the corner of the mouth to the side, while reducing on both sides, allows you to draw the inner surface of the cheeks to the jaw.
- Muscle laughter. Action: allows the corners of the mouth to stretch laterally.
- Two chin muscles. Features of the facial muscles of this type are that one of them is unstable, can be reduced. Function: provide movement of the skin of the chin, and also pull the lower lip forward.
- The muscle lowering the lower lip. The value according to the name.
These are all the main mouth facial muscles of the face, the anatomy of which allows a person to smile, talk, express joy and discontent, move his mouth.
Muscles encircling the nose
This group includes only two main muscles:
- nasal muscle, folding from the inside and outside. Action: provide movement of the nostrils and nose;
- 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 listed muscle groups of the eye, mouth, nose, and cranial vault are the main components of facial expressions. Thanks to the presence of these muscles, people manage to convey a gamut of feelings, communicate with each other even without words, and reinforce phrases with the necessary visual expression.
Facial 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 are well aware of the anatomy of the muscles.
Chewing muscles: varieties
Mimic and chewing muscles are the main components of the face and head. If the first refers to 17 different structures, then to the second group - only 4. However, it is these four chewing muscles that play an important role in human life, as well as in maintaining a beautiful young face shape. Consider exactly what structures belong to them.
- Chewing - the strongest muscle trained by a person during a meal. It is located in two parts: deep and superficial. It starts from the zygomatic arch and attaches to the muscles of the lower jaw.
- Temporal - starts from the process of the temporal bone and stretches to the lower jaw.
- Pterygoid lateral - consists of two parts: the upper and lower heads. It starts from the site of the sphenoid bone and ends in the muscles of the lower jaw, forming a complex weave with them.
- The pterygoid medial is also located from the sphenoid bone to the lower jaw.
All these muscles are united by a community of functions that we will now consider.
Functions
Naturally, since the muscles belong to the group of chewing, then their action will be appropriate: ensuring the versatile movement of the jaw:
- Chewing - the lower jaw raises and pushes forward.
- Medial - provides lateral and other movements of the lower jaw.
- Lateral - has similar functions to the medial.
- Temporal - the main assistant for chewing movements. It pulls the lower jaw forward, and also allows it to rise up to close with the upper.
In addition, it is the temporal muscle that gives a person a tired, tired and haggard look. If for a long time to be in a state of nervous tension, acute feelings and stress, the body will begin to lose weight, and the person takes on a corresponding haggard expression. This is due to the fact that the temporal muscle is thinning and, stretching over the skin of the face, visually changes its relief.
Thus, we can conclude that facial and masticatory muscles are the constructors of our face that allow us to embed any expression, make various movements and change different grimaces. And also they allow chewing, which, undoubtedly, is one of the most important life processes of most living things, including humans.