Basic Information
Chinese name: breast
Pinyin: rǔ fáng
Body part: pectoralis major
Owned by: Human females and other female mammals
Components: skin, fibrous tissue, adipose tissue
basic concept
The breast is located in the upper abdomen of the mammalian torso, and in most cases it refers specifically to the breast of a human female. For most mammals, the breast is the organ used by female mammals to nurture their young; for humans, the developing breast is one of the secondary sexual characteristics of women. Male mammals (including human males) have breast tissue such as mammary glands in infancy, but they do not develop during the growth process of infancy.
Features introduction
Women's breasts are important sexual organs of women and play an important role in sexual activity. In women, it is not only an aspect of female bodybuilding, but also a sensitive area. Men touching their breasts can arouse women's lust. Breasts and nipples are rich in nerve endings, and stimulation of female breasts can produce sexual arousal. For men, women's breasts have a timeless allure. In systematic anatomy, the breast belongs to the female reproductive system.
Female breasts are located on the pectoralis major muscle, usually extending from the second rib to the sixth rib, medially to the parasternal line, and laterally to the midaxillary line. Breast (mamma; breast) is a unique structure of mammals. While women begin to develop and grow after puberty, the breasts during pregnancy and lactation have secretory activity.
Breasts are secondary sex organs, and female breasts are also breastfeeding organs. Breasts are mainly composed of connective tissue, adipose tissue, mammary glands, a large number of blood vessels and nerves. The position of the breasts changes with age. The breasts of adult women are located in the superficial fascia above the pectoralis major, with the upper and lower borders being flush with the 2nd and 6th ribs, respectively. Below is an overview of the main tissues that make up the breast.
Breast tissue: The adult female breast tissue consists of 15-20 mammary lobes. Its main function is to produce milk, and it also has the role of showing female characteristics. The mammary lobes consist of many mammary lobules, which contain many acinars.
Adipose tissue: Adipose tissue wraps the entire breast tissue (except the areola). Thicker layers of adipose tissue mean larger breasts, and vice versa.
Connective tissue: that is, the fiber bundles that connect the superficial chest muscles and the pectoralis fascia, which support and fix the breast.
Blood vessels, lymph vessels and nerves: Breasts are rich in blood vessels and nerves. The main functions of blood vessels and lymph vessels are to supply nutrients and remove waste. The nerves are connected to the sensory receptors in the breast skin, which sense external stimuli.
Morphology
Breast Internal Structure Diagram Breast is composed of skin, fibrous tissue, adipose tissue, and mammary gland. Adipose tissue is mainly located under the skin. Fibrous tissue mainly surrounds the mammary gland, but does not form a complete cyst. A fibrous tissue is embedded between the mammary lobes, dividing the gland into 15 to 20 mammary lobes Lobes of Mammary gland. One lobe has excretory ducts, called Lactiferous Ducts, that run toward the nipple, where the ducts expand near the nipple into Lactiferous Sinuses, which taper at the ends and open into the nipple. The mammary lobes and milk ducts are arranged radially with the nipple as the center. During breast surgery, radial incisions should be made as much as possible to reduce damage to the breast lobes and ducts. The fibrous tissue surrounding the mammary gland sends out small fibrous bundles deep to the thoracic fascia. The fibrous tissue from the surface of the mammary gland also produces small fiber bundles connected to the skin and the nipple, and these fiber bundles are more developed in the upper part of the breast.
These bundles of fibers are called Suspensory Ligaments of Breast or Cooper Ligament, and they hold the breast in place. In the early stage of breast cancer, due to the invasion of the suspensory ligament of the breast, the fibrous tissue proliferates and the ligament shortens, causing some depressions in the surface skin. In the advanced stage of cancer, due to the obstruction of lymphatic flow, tissue edema occurs, and the cancerous area is tightly adhered to the skin, especially the hair follicles of the skin are more closely adhered to the deep layers, resulting in many small depressions on the skin, and the skin is orange peel-like. These features aid in the diagnosis of breast cancer.
Internal structure of the breast: The breast is mainly composed of glands, ducts, adipose tissue and fibrous tissue. Breast glands consist of 15 to 20 glandular lobes, each glandular lobe is divided into several glandular lobules, and each glandular lobule consists of 10 to 100 acini. The acini are closely arranged around the small milk ducts, and their openings connect with the small milk ducts. Many small milk ducts merge into interlobular milk ducts, and many interlobular milk ducts merge into a whole glandular lobe of breast ducts, also known as lactiferous ducts. There are 15 to 20 lactiferous ducts in total, which are arranged radially with the nipple as the center, and converge in the areola. The lactiferous ducts are narrow at the nipple, and then expand into the ampulla, called the lactiferous sinus, which can store milk. The amount of adipose tissue is one of the important factors in determining breast size.
External structure of the breast: The nipple is composed of dense connective tissue and smooth muscle. Smooth muscles are arranged in a circular or radial pattern. When there is mechanical stimulation, the smooth muscles contract, which can make the nipple erect, and squeeze the duct and the lactiferous antrum to discharge its contents. The areola skin has hairs and glands. The glands are sweat glands, sebaceous glands and mammary glands. The sebaceous glands, also known as areola glands, are large and superficial, and their secretions protect the skin, lubricate the nipple and the baby's lips.
The mammary glands are located between the superficial and deep layers of the subcutaneous fascia. The superficial fascia extends into the breast tissue to form a lobular septum, and one end is connected to the pectoralis fascia. The other end is attached to the skin, securing the breast glands in the subcutaneous tissue of the chest. These fibrous connective tissues that support and hold the breast in place are called the suspensory ligaments. The deep layer of the superficial fascia is located on the deep surface of the breast, and is connected with the superficial layer of the pectoralis major fascia, which can make the breast relatively fixed and have a certain mobility on the chest wall. Sometimes, part of the breast glands can penetrate into the superficial layer of the pectoralis major muscle through the loose tissue. Therefore, the pectoralis major fascia and muscle should be removed together during radical breast cancer surgery.
1. Location and morphological structure The breasts are underdeveloped in children and men, and the breasts of non-lactating women in puberty are hemispherical. Located at the height of the 2nd to 6th ribs, between the superficial and deep layers of the superficial fascia, on the surface of the pectoralis fascia, from the parasternal line outwards to the midaxillary line. Breasts contain mammary glands and fat. The mammary gland is divided into 15 to 20 glandular lobes by connective tissue, and each glandular lobe is divided into several lobules. Each glandular lobe has a lactiferous duct, which is arranged radially with the nipple as the center and ends at the nipple.
When the breast abscess is incised and drained, a radial incision should be made to avoid cutting off the lactiferous duct, and attention should be paid to the separation of the connective tissue interval to facilitate drainage. There are many fibrous bundles perpendicular to the skin in the connective tissue between the gland lobes, one end is connected to the skin and the superficial layer of the superficial fascia, and the other end is connected to the deep layer of the superficial fascia, which is called the suspensory ligament of the breast or Cooper's ligament. Because the two ends of the ligament are fixed and there is no stretch, in breast cancer, the skin there appears sunken. There is a gap between the deep layer of the superficial fascia and the pectoralis fascia, called the retromammary space, which contains loose junctional tissue, fat and lymphatic vessels. The latter receives the lymph in the deep part of the breast. Inflammation of this gap is easy to expand downward, and it is advisable to perform low-level incision and drainage.
2. Lymphatic reflux The female breast is rich in lymphatic vessels, which are divided into two groups: superficial and deep. The superficial group was located in the skin and subcutaneous, and the deep group was located around the breast lobules and in the wall of the lactiferous duct. The two groups were extensively anastomosed. The lymph from the breast is mainly injected into the axillary lymph nodes, and some of them go to the parasternal, interpectoral, and septal lymph nodes.
(1) The lymphatic vessels in the lateral and central parts of the breast are injected into the pectoral lymph nodes of the axillary lymph nodes, which are the main routes of breast lymphatic drainage.
(2) The lymphatic vessels in the upper part of the breast feed into the apical lymph nodes of the axillary lymph nodes and the supraclavicular lymph nodes.
(3) The lymphatic vessels in the medial part of the breast flow into the parasternal lymph nodes and match with the lymphatic vessels of the contralateral breast.
(4) The lymphatic vessels in the lower part of the breast are injected into the upper septal lymph nodes, and are matched with the lymphatic vessels in the upper part of the anterior abdominal wall and the lower part of the septum, thereby indirectly connecting with the lymphatic vessels above the liver.
(5) The lymphatic vessels in the deep breast pass through the pectoralis major muscle and inject into the interpectoral lymph nodes or apical lymph nodes through the posterior space of the breast. The interpectoral lymph nodes, also known as Rotter nodes, are located between the major and minor pectoralis muscles and are often involved in breast cancer. The superficial lymphatic network of the breast is widely anastomosed, and the two sides communicate with each other. When breast cancer involves the superficial lymphatic vessels, it can lead to the obstruction of lymphatic flow in the collected area, resulting in lymphedema, and the local skin will appear punctate depression, showing "orange peel-like" changes, which is an important basis for the diagnosis of breast cancer.
Adult female nulliparous breasts are hemispherical, tight and elastic. The nipple, Mammary Papilla, is located in the center of the breast, with the opening of the milk duct at the top. There is a more pigmented skin area around the nipple, called the Areola of Breast. There are many small bumps on the surface. The deep surface is the areola gland, which secretes fatty substances to lubricate the nipple. The skin on the nipple and areola is weak and prone to damage. Mammary gland hyperplasia during pregnancy and lactation, the breasts are significantly enlarged. After you stop breastfeeding, the mammary glands shrink and the breasts become smaller. Breast atrophy is more pronounced in older women.
In an adult nulliparous woman, the breasts are hemispherical, tight and elastic. During late pregnancy and lactation, the breasts are significantly enlarged due to hyperplasia of the mammary glands. When breastfeeding stops, the mammary glands shrink and the breasts become smaller. Breasts in older women are sagging and sagging due to the reduction of elastic fibers. In the middle of the breast surface is the nipple (Mammary Papilla), the top of which has the opening of the lactiferous duct. The nipple is composed of dense connective tissue and smooth muscle. When the signal comes, the smooth muscle will contract the backlogged ducts, the nipple will erect and straighten, and the milk can flow along the lactiferous duct and out through the small hole of the nipple. The area of skin with more pigmentation around the nipple is called the areola (Areola of Breast). There are many small dot-like bumps on the surface of the areola, which are the openings of the deep areola glands. Protect nipples. The skin of the nipple and areola is weak and easily damaged.
specific division
Disc type: The breasts are not raised high, but the bottom is not small, like two thin plates hanging on the chest.
Conical type: The breast is small and the bottom is not large, but the whole is hammered and pulled out, and it is conical.
Hemispherical: The breasts are large and full, like the two halves of a tennis ball.
Spindle type: The breasts are high up but not large at the bottom, making the breasts protrude forward and sag slightly, like a spindle.
Sagging Type I: The breasts are raised but sagging, with a portion of the lower side touching the chest.
Sagging Type II: The apex of the breast is positioned so low that the entire breast hangs downward. [3]
The six types of breasts do not change with age, but exist simultaneously in the reproductive age group. Not only that, but there are also certain differences between the right and left breasts of each person.
developmental process
Stage 1 (1 to 9 years old): Before puberty, the breasts have not yet developed.
The second stage (10 to 11 years old): In the early stage of breast development, the mammary germ under the nipple begins to grow, showing an obvious dome-shaped bulge.
Stage 3 (12-13 years old): The breasts become round and adult-like, but still small.
Stage 4 (14 to 15 years old): The breasts enlarge rapidly, the nipples and areola protrude forward and are shaped like small balls. If you are still about the same age as 13, look for the reason. as shown
The fifth stage (16 to 18 years old): The normal adult breasts are formed, and the small balls of the nipple and areola are integrated with the round shape of the breast.
breast development
Affected by factors such as region and ethnicity, the time when female breasts begin to develop varies. The vast majority of female breasts begin to develop between the ages of 8-13 and fully mature between the ages of 14-18. Breast development mostly starts from the left side, and it takes about 3-5 years from the beginning to full maturity.
Improper breast development
1. Multiple breasts, multiple nipples
If the embryonic breast primordium is not degenerated or incompletely degenerated, there will be multiple nipples or multiple breasts. Most occur on the starting line of mammogenesis, that is, on the line from the axilla to the groin.
2. Abnormal nipples
An abnormal nipple is an abnormality in its size, shape, and location. Normal nipples are cylindrical and protrude about 2 cm above the surface of the breast skin. Abnormal nipple placement is common. According to the relationship between nipple and breast skin, it can be divided into flat nipple, inverted nipple and inverted nipple.
3. Breast hypertrophy
One of the abnormal breast development in women is breast hypertrophy. Macromastia mostly occurs in puberty and pregnancy. The reason is not clear, but it may be caused by the excessive sensitivity of breast tissue to estrogen.
4. Low breast development
Breasts that are too small, missing one or both breasts. Absence of both breasts and nipples is called complete breast absence. Those who have only nipples but no breasts are called partial breast absence.
breast health
Both breasts are larger on one side and smaller on the other; one nipple sticks out and the other nipple is slightly retracted, and so on. If this has been the case all the time, it's not new, and it's never been uncomfortable, then it's normal and nothing to worry about. If both breasts are significantly asymmetrical, the following conditions may occur:
First, congenital factors. During embryonic development, if one side of the breast is abnormally developed at the beginning, in the future puberty breast development, the two breasts will be significantly asymmetrical, and the dysplastic side will be significantly smaller than the other side. Generally speaking, this situation will not affect marriage and fertility, but it will lose the unique curvaceous beauty of women. Therefore, after puberty breasts are fully developed, breast augmentation with prosthesis implantation can be performed selectively, so that the originally flat side of the breast is as full as the healthy side, and the woman's style and self-confidence can be restored.
Second, the acquired factor. Usually occurs in multiparous women. When breastfeeding, mothers are often accustomed to breastfeeding in one direction, so that the breastfeeding opportunities on both sides are unequal. After weaning, the side with more opportunities is more likely to atrophy and degenerate and become smaller than the opposite side. This condition is generally not uncomfortable and does not affect life. You can exercise the chest muscles on the side of the smaller breast, and massage the smaller breast. If necessary, you can use external breast enhancement drugs or equipment (pay attention to the authenticity of the various brands on the market, and choose carefully). Of course, if you pay attention to alternate breastfeeding on both sides of the breast when breastfeeding, and have an equal chance, this situation can be avoided. In addition, if the breasts were generally symmetrical in the past, and asymmetry develops recently, such as breast enlargement on one side, skin color changes or small depressions in the skin on one breast, retraction or elevation of the nipple on one side, and sometimes Special attention should be paid to symptoms and signs such as pain, itching, and nipple discharge. In this case, you should see a doctor immediately for relevant tests to detect possible lesions as early as possible.
Other factors that affect breast health
1: High-fat diet becomes breast "killer"
Two: Abuse of essential oils increases estrogen in the body
Three: Singles and Dinks are in crisis
Four: Bad mood destroys breast health
Risk factors for breasts also include: genetic factors, ionizing radiation
