The chest shape has several functions: 1. According to the length of breast protrusion, breast can be divided into the following types: (1) flat type: the length of breast protrusion is less than the radius of breast base, and the breast is slightly discoid. The protrusion of the chest wall is gradually excessive and the boundary is not obvious. There was no obvious change in breast shape when standing and supine. (2) Hemisphere: The protruding length of the breast is equal to the radius of the breast base, which looks like a hemisphere. The breast suddenly bulges on the chest wall with obvious boundary, which is round and hemispherical. You can still see the obvious breast curve when you lie on your back. According to China's aesthetic standards, these breasts are the best. (3) Conical shape: the length of breast protrusion is greater than the radius of breast base, and the angle between the lower edge of breast and chest wall is less than 90. The breast has an obvious downward arc, towering and slightly drooping when standing. (4) drooping: the breast protrusion is long, and the breast droops in a bag shape when standing, and the breast droops outward when lying on your back. 2. Physiological function of breast: (1) Breastfeeding: This is the most basic physiological function of all mammals. The development and maturity of mammary glands are the preparations for this breastfeeding activity. After delivery, under the stimulation of a large number of hormones and the sucking of the baby, the breast began to produce and secrete milk regularly for the growth and development of the newborn. (2) Secondary sexual characteristics: Breast is an important symbol unique to women. Girls begin to develop at the age of 10, which is the earliest secondary sexual characteristic. It is the dream of many girls to have a pair of tall and straight breasts. Otherwise, how can many girls go through the pain to get plastic surgery or wear artificial limbs? (3) Participatory activities: In sexual activities, breast, as one of the sensitive parts of women, will produce a series of changes under the stimulation of touching and kissing. Such as nipple erection and full breasts, are conducive to harmonious sexual life, thus enhancing the feelings of husband and wife. Therefore, women's breasts are not only breast-feeding organs, but also symbols of beauty and love. Pages you may care about: