Why is a human head round and not square?

The circle is the most perfect figure, it is perfectly symmetrical, the resistance to the same volume is the least, and changing to other shapes will bring inconvenience to various activities of the body, so the head is round. In fact, every joint part of the human body is composed of a circle, because only the movement of the circle is the most convenient, and those parts that are not round are rods, which all play the role of levers. The human head shape is so large that it can be divided into several shapes, such as large, small, long, pointed, and round.

The structure of the human head mainly refers to the anatomical structure and physical structure of the head. Mastering the structure of the human head is the basis for the sketching of the human head. The shape structure of the head is mainly manifested in three aspects: body structure, shape characteristics and basic proportions of the head.

The skeleton shape of the head of the body structure is between a sphere and a cube.

The head is divided into two parts: the skull and the face. The skull is oval in shape, occupying 1 3 of the head, and the frontal area of the skull forms a square mass. The facial skull consists of a flattened mass in the zygomatic area, the maxilla.

area of cylindrical mass, mandible.

The triangular mass of the partial area is composed of about 2 3 of the head. The physical features of the head and the coordinated undulations of the face are formed by the interweaving relationship between the four bodies of the brain and the face, as well as the front, cheeks, maxilla, and mandible. The shape of the skull determines the shape of the head.

It shows not only differences in gender and age, but also various personality differences. Physical features of male and female heads. The male head is larger and tends to be square, with a backward forehead and arched eyebrows.

It is more prominent with the nasal bone, with a square band on the lower jaw and front, and a prominent occipital region. In terms of appearance, the male head line tends to be straight, and the body fluctuates greatly. The head volume of women is smaller, and the bulges and nodules of the face are not as prominent as those in men, but the frontal mounds and cranial parietal mounds are more prominent.

The forehead is straight, the jaw is pointed, and the face is rounded. In terms of appearance, the female head line tends to be softer, the body shape is less undulating, and the appearance of the head is characteristic of the elderly and juveniles. In the elderly, the parietal mound of the head is conspicuous due to sparse hair, and teeth are lost, resulting in a sunken gum.

The shortening of the face, the concentration of facial features, the constriction of the mouth, and the protruding and forward-turned chin are the distinctive features of the head in old age. The volume of the skull of the head of young children accounts for 5 6 of the head, and the facial skull occupies only 1 6 of the head. The parietal bones are raised, the frontal mounds are high and prominent, and the lower jaw is small and rounded.

The most prominent features of the skull are large skulls, adducted chins, and shortened distance from the base of the nose to the lips. Different types of head features. The muscles of the human head are relatively shallow, and the basic stylistic characteristics of the head are determined by the shape of the skull.

The traditional Chinese theory of "eight grids" is an excellent summary of the appearance characteristics of the head. <>

The basic proportions of the head. The basic proportion of the head is "three courts and five eyes", the hairline to the eyebrows, the eyebrows to the tip of the nose, the tip of the nose to the chin, the length of the three segments is equal and is commonly known as the "three courts"; The widest part of the face from the front is the width of the five eyes, the distance between the two eyes is one eye wide, and the outer canthus of the two eyes to the two ears are one eye wide, that is, the position relationship between the head and the five senses, the eyes are about 1 2 places on the head and face, and the canthus at the two eyes to the tip of the nose form an isosceles triangle, the height of this triangle determines the physical characteristics of the middle of the face. The nose protrudes in the middle of the face.

The tip of the nose is located from the frontal hairline to the base of the chin1 3, and the width of the alar is the width of one eye, and the width of the alar is determined by the vertical line from the inner canthus. The cleft of the mouth is located from the tip of the nose to the base of the mandible1 3. The ears are on the left and right sides, the length of the ears is equal to the distance from the eyebrows to the tip of the nose, the inclination of the ears and the nose is basically the same from the side, and the distance from the tragus, the corners of the mouth to the canthus is equal when the ears are from the positive side.

The relationship between the head, neck, and chest, through which the head is connected to the chest. The neck resembles a cylinder, located between the head and the thorax. The head and neck, neck and chest are structurally embedded in each other, like a carpenter's tenon.

Since the cervical spine has a natural physiological curve, the neck is not vertical, and in the natural normal, the head is not vertical. Viewed from the side, the neck is oblique and rectangular, with the head attached to the neck in the anterior position; Viewed from the front, the neck is bounded from both sides of the mandible, and the cylindrical neck is made up of three triangular faces. The length of a man's neck (from the base of the jaw to the collarbone) is equal to the length from the floor of the jaw to the floor of the nose.

On both sides of the neck, from the clavicle and sternum on both sides of the cervical fossa to the mastoid process behind the ears, there is a pair of "sternocleidomastoid muscles", which stretch and contract to rotate the neck (head). <>

All evolution follows this maximization. A round head has the following advantages over a square head.

First; Safe, the strongest ability to withstand external forces, the egg shell is very thin, and it is not broken with one hand.

Second; The effective volume is large.

Third; The sleek shape reduces the risk of injury and, in addition to the high bearing force mentioned in the first article, can also deflect the direct force.

Fourth; Easy to produce.

The human head, the head of a person (i.e., the uppermost part of a person, supported by a person's skull). Poll tax. During the Elizabethan period in England, a tax was levied on the basis of capitation, but it was met with strong resentment and ended in failure.

In ancient times, human heads were also seen as the spoils of the victors.

The human head, the head of a person (i.e., the uppermost part of a person, supported by a person's skull). Poll tax. During the Elizabethan period in England, a tax was levied on the basis of capitation, but it was met with strong resentment and ended in failure.

In ancient times, human heads were also seen as the spoils of the victors. The human head, the head of a person (i.e., the uppermost part of a person, supported by a person's skull). Poll tax.

During the Elizabethan period in England, a tax was levied on the basis of capitation, but it was met with strong resentment and ended in failure. In ancient times, human heads were also seen as the spoils of the victors. Number.

Mao Dun's "Sending the Exam": "You can't wait; Let's get together and hire a taxi! Poll tax.

During the Elizabethan period in England, a tax was levied on the basis of capitation, but it was met with strong resentment and ended in failure. Killing an opposing player in a competitive game is known as taking a head. The human head is also known as the emblem in the online game World of Warcraft.

In ancient times, human heads were also seen as the spoils of the victors. <>