Eyelash and eyebrows

Different positions have different functions.

Eyelashes grow on the front lip of the eyelid margin, arranged in 2-3 rows, short and curved.

Eyelashes on the upper eyelid are numerous and long, usually 65,438+000-65,438+050, with an average length of 8-65,438+02 mm, slightly growing forward and upward. In general, the inclination of upper eyelid eyelashes is 79.8% when eyes are open, 1 10 degrees for men, 140 degrees-160 degrees for women and men, and 83.5% when eyes are closed.

The eyelashes of the lower eyelid are short and few, about 50-75, and the length is about 6-8mm, slightly bending forward and down. Male lower eyelid eyelashes 100 degrees-120 degrees, and females are l0 degrees smaller than males.

When you close your eyes, your upper and lower eyelashes are not intertwined. The eyelashes in the central part of the upper and lower eyelids are longer and more, and the inner canthus is the shortest.

Eyelash hair follicles are rich in nerves, so eyelashes are very sensitive, and touching eyelashes will cause a blink response. There are sweat glands and sebaceous glands around the hair follicle, and their excretory ducts open in the eyelash hair follicle.

Eyelashes are generally darker than hair, and will not turn white due to old age (occasionally a few senile cilia can be seen), but they can also turn white due to certain diseases, such as albinism.

Function of eyelashes

Eyelashes have a protective effect.

Eyelashes at the upper and lower eyelid margins are arranged at the edge of the eyelid cleft like guards. Eyelashes are the second line of defense for the eyes. Anything close to the eyes must touch the eyelashes first, and the eyelashes will immediately cause a closed-eye reflex to protect the eyeball from foreign invasion. It has shading effect, prevents dust, foreign matter and sweat from entering eyes, and protects cornea and eyeball together with eyelids. Eyelashes can also prevent ultraviolet rays from damaging the eyes.

eyebrow

A human hair, located above the eyes. It has a protective effect on the eyes.

Eyebrows are closely related to hair follicles and nipples. The basal part or papilla of each normal hair follicle has a different number of blood vessels extending into the hair bulb. These blood vessels communicate with the branches around the lower part of the hair follicle, forming a capillary network leading to the nipple, while the capillary network under the nipple on both sides of the hair follicle and the capillary network in the connective tissue layer of the hair follicle form a rich vascular plexus. Blood passes through these vascular networks and vascular plexus, providing material nutrition for hair growth.

The growth of hair depends not only on the blood circulation around the hair follicle to supply nutrition, but also on the control and regulation of nerves and endocrine. Endocrine has obvious influence on hair, and androgen can promote hair follicle sheath to some extent. Endocrine includes pituitary gland, gonad, thyroid gland and adrenal gland. Therefore, mental stress and physiological reasons can also lead to eyebrow removal and eyebrow loss.

The growth and replacement of eyebrows also have certain rules, not continuous, but periodic. The growth cycle of hair is divided into three stages: from growth period (i.e. active period)-rest period-shedding period.

The growth period of eyebrows is about 2 months, and the dormancy period can be as long as 3-9 months, and then they naturally fall off. The speed of hair growth is influenced by gender, age, place and season. For example, hair grows about 0.3-0.4 mm every day, armpit hair is 0.2-0.38 mm, and eyebrows are about 0.2 mm. Hair grows most vigorously at the age of 15-30, and grows slightly faster in summer than in winter.

It is related to physical condition through eyebrows. Huangdi Neijing: "Those who have beautiful eyebrows are full of yang and blood, and those who hate eyebrows are few." It can be seen that the eyebrows are rich, dense and moist, reflecting the vitality of the meridians of the foot sun; If the eyebrows are thin and short, thin and light, and fall off, it is a symbol that the sun passes through insufficient blood gas. Thick eyebrows indicate that the kidney is full and strong; But thin and weak eyebrows indicate weakness. If kidney qi is sufficient, sexual desire will naturally flourish. That's the truth.

Careful observation shows that if the eyebrows often fall off, especially on the outside of the eyebrows, it means that you have hypothyroidism and pituitary hypofunction; Leprosy patients may have 1/3 skin hypertrophy and eyebrows falling off in the early stage; In patients with vitiligo, the root hair of eyebrows turns white first; Some alopecia areata patients will suddenly lose their eyebrows overnight; Eyebrows are tight from time to time, which is a manifestation of pain; If there are some small particles on the skin of eyebrow root, it may be a manifestation of diabetes or angina pectoris; Patients with malnutrition will also have inverted eyebrows and eyebrow removal. Someone once put forward an absurd theory that a virgin's eyebrows are locked, not scattered. This statement has no scientific basis. Mainly influenced by ancient literary works. This is because girls in ancient times couldn't get out and were depressed, so they were sad all day.