All people have good and bad 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 it about the structure of the face that allows us to be so different, alive, interesting and multifaceted in expressing emotions? It turns out that this is the merit of different types of muscles. It is about them that we will talk 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 discussed in ancient times. The Egyptians, Romans, Persians, Chinese mention in their books about these structures located under the human skin. However, descriptions of specific muscles as such are found much later. So, Leonardo da Vinci made a huge contribution to this. Of the more than 600 drawings on human anatomy that he left behind, most of them are dedicated specifically to the muscles, their location on the body, structure, and appearance. Muscle descriptions are also found inthe works of Andreas Vesalius.
The physiology of muscle work was studied by the following scientists of the 18th-20th centuries:
- Luigi Galvani - discovered the phenomenon of electrical impulses in muscles and animal tissues.
- Emile Dubois-Reymond - formulated a law reflecting the action of current on excitable tissues
- N. E. Vvedensky - described and established the optimum and pessimum of electrical excitation in the muscles
- G. Helmholtz, J. Liebig, Wislitsenus, V. Ya. Danilevsky and others - studied and described in detail all the physiological features of the functioning of muscle tissue, including heat transfer during physical exertion 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 is so important for medicine.
Quantity and definition of human muscles
In total, there are about 640 muscles in the human body, each of which performs its own specific function. Muscle anatomy is a collection 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 held together by a loose connective tissue structure. In the human body, they form a whole system of skeletal muscles (striated tissues) and line many organs and vessels (smooth tissues).
Classification
According to the functions performed, the muscles are divided into the following groups:
- Diverters.
- Reducing.
- Supinators.
- Sphincters.
- Dilators.
- Spinners.
- Flexors.
- Extensors.
- Opposite.
- Pronators.
There is also a classification of muscles according to their location in the human body. So, allocate:
- trunk muscles (superficial and deep);
- muscles of limbs;
- muscles of the head (facial and chewing).
Shape
On this basis, 7 main muscle groups are distinguished, and each group is localized and functional in a certain part of the human body.
- Spindle.
- Square.
- Flat.
- Straight.
- Triangular.
- Cirrus.
- Circular.
Muscle Anatomy
Each muscle has approximately the same internal structure plan: the outside is covered with epimysium - a special sheath substance produced by connective tissue. From the inside, it is a set of muscle bundles of various orders, which are combined at the expense of endomysium - connective tissue. At the same time, a number of blood vessels and capillaries approach each muscle for an adequate supply of oxygen during work. The veins take away decay products and carbon dioxide. Nerves penetrating the fibers provide conductivity, excitability, and fast and high-qualityfeedback (work).
The muscle cells themselves have several nuclei, since during active work they are able to produce thermal energy due to numerous mitochondria. Muscles owe their ability to contract to special proteins: actin and myosin. It is they who 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).
Head muscles
This group includes several basic types. The main ones are:
- facial muscles (facial muscles) - responsible for facial expressions, external manifestations of emotions;
- chewing - perform the function of the same name.
Besides them, muscles are distinguished:
- eyeball;
- auditory ossicles;
- language;
- sky;
- Zeva.
The peculiarity of the structure of all the muscles of the head, except for the buccal, is the absence of fascia - a special "bag" in which all the muscles are located and which is attached directly to the bones. Therefore, the vast majority of them are attached to the bones with one side, and the other freely flows directly into the skin, tightly intertwining with it into a single structure.
Mimic facial muscles: types
The most interesting and clearly showing their work outwardlyare just facial muscles. Thanks to their function, that is, the ability to form a person's facial expressions, they got their name - facial muscles.
There are quite a lot of them. After all, one has only to remember how bizarre and diverse the expressions of our emotions can be in order to understand that one or two cannot cope with such work alone or together. Therefore, the facial muscles act in whole groups, and there are 4 in total:
- Forming the vault of the skull.
- Shaping the circumference of the mouth.
- Girdle nose.
- Shaping the circle of the eyes.
Let's look at each group in more detail.
Cranial vault muscles
Mimic muscles of the head, forming the vault 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 performed by such facial muscles of the head is the formation of transverse skin folds on the forehead of a person.
The same group includes the anterior and posterior auricular muscles. Their main action is to allow the auricle to move up, down, forward and backward.
The transverse nuchal 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 that form the circumference of the eye
These are the most expressive facial muscles. Their anatomy does not imply the presence of fascia, and the shape of such structures is different.
- Circular muscle completely encircles the eyeball in a circle underskin. It consists of three main parts: orbital, secular and lacrimal. Action - opening and closing the eyes, controlling the flow of tears, lowering the eyebrows down, smoothing the wrinkles on the forehead.
- Mimic 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 bridge of the nose.
- The muscle of the proud - the name itself speaks of the meaning - forms transverse folds at the base of the nose, giving the face an expression of pride and impregnability.
Such mimic facial muscles allow people to express their emotions only with their eyes, eyes and skin around them. A lot can be said without words thanks to such structural features of the human body.
Muscles that form the circumference of the mouth
No less important are the other mimic muscles of the face. The anatomy of this group of muscles is represented by a circular structure surrounding the mouth opening. Several main muscles act here, which are antagonists in relation to each other. This means that some of them expand the oral fissure, and some, on the contrary, narrow it.
- Muscle of the mouth, called circular. Action: constriction of the oral fissure and forward movement of the lips.
- Zygomatic muscles (large and small). Functions: Allow the corner of the mouth to move up, down and sideways.
- Features of the facial muscles of the mouth are that they allow it to move. So, for example, at the base of the upper jaw there is a muscle that allows you to raise the upper lip. Nearby is one that raises the wing of the nose.
- Buccal muscle. Meaning: pulls the corner of the mouth to the side, while contracting from both sides allows you to pull the inner surface of the cheeks to the jaw.
- The muscle of laughter. Action: allows the corners of the mouth to stretch laterally.
- Two chin muscles. Features of the mimic muscles of this type are that one of them is unstable and can be reduced. Function: Provides movement to the skin of the chin and also pulls the lower lip forward.
- The muscle that lowers the lower lip. Value according to the name.
These are all the main facial facial muscles of the mouth, the anatomy of which allows a person to smile, talk, express joy and displeasure, move his mouth.
Muscles around the nose
This group includes only two main muscles:
- nasal muscle, consisting of the inner and outer parts. Action: move the nostrils and nose;
- muscle that lowers the nasal septum.
Thus, there are only two facial muscles in the circumference of the nose. 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 range of feelings, communicate with each other even without words, and reinforce phrases with the necessary visual expression.
Mimic muscles are very important structures that are also responsible for the formation of wrinkles during the aging process. That is why all the centers involved in plasticsurgery and similar procedures are recruiting highly qualified specialists who have a good knowledge of muscle anatomy.
Chewing muscles: varieties
Mimic and chewing muscles are the main components of the face and head. If the first group includes 17 different structures, then 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 oval. Let's consider what structures are related to them.
- Chewing - the strongest muscle trained by a person during meals. It is located in two parts: deep and superficial. 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: upper and lower head. It starts from the site of the sphenoid bone and ends in the muscles of the lower jaw, forming a complex interlacing with them.
- Pterygoid medial - also located from the sphenoid bone to the lower jaw.
All these muscles are united by the commonality of their functions, which we will now consider.
Functions
Naturally, since the muscles belong to the chewing group, then their action will be appropriate: ensuring the versatile movement of the jaw:
- Chewing - lower jaw lifts and pushes forward.
- Medial - provides lateral and otherlower jaw movements.
- Lateral - has similar functions to the medial.
- Temporal - the main assistant in chewing movements. Pulls back the protruding lower jaw, and also allows it to rise up to close with the upper one.
In addition, it is the temporal muscle that gives a person a tired, tired and haggard look. If you are in a state of nervous tension, acute feelings and stress for a long time, the body will begin to lose weight, and the face takes on a corresponding haggard expression. This is due to the fact that the temporalis muscle becomes thinner and, being fitted by the skin of the face, visually changes its relief.
Thus, we can conclude that the facial and chewing muscles are the constructors of our face, allowing you to embed any expression, make a variety of movements and change various grimaces. They also allow chewing, which is undoubtedly one of the most important life processes of most living beings, including humans.
