The Breast (Mammary Gland) Anatomy & Physiology PDF

THE BREAST (Mammary Gland) ABIODUN-OJO O.E  ANATOMY OF THE BREAST Extends laterally from the sternum to the axilla Lies anteriorly on the chest on the pectoralis muscle Positioned between the 2nd and 6th rib of the thorax It may be hemispherical, conical or pend...

THE BREAST (Mammary Gland) ABIODUN-OJO O.E  ANATOMY OF THE BREAST Extends laterally from the sternum to the axilla Lies anteriorly on the chest on the pectoralis muscle Positioned between the 2nd and 6th rib of the thorax It may be hemispherical, conical or pendulous Breast is reinforced by the coopers ligament It is Composed of varying proportions of fat, glandular and connective tissue Tissues are arranged in lobes subdivided into lobules. Each lobule is subdivided into http://physiologyplus.com/physiology-of-lactation/ lobules and consists of alveoli and ducts  ANATOMY OF THE BREAST Alveoli contain milk producing acini cells, Acini cells are surrounded by myoepithelial cells, Small lactiferous ducts unite to form larger ducts (lactiferous tubules). Lactiferous tubules emerge on the surface of the nipple  ANATOMY OF THE BREAST The human nipple is covered with epithelium Nipple contains cylindrically arranged smooth muscle and elastic fibre. Surrounding the nipple is an area of pigmented skin called the areola.  ANATOMY OF THE BREAST BLOOD SUPPLY Supplied by internal and external mammary arteries and branches from the intercostal arteries Veins are arranged in circular fashion around the nipple http://www.webset-lms.com/vtct/Course.aspx?id=4767 ANATOMY OF THE BREAST LYMPH DRAINAGE Lymph drainage is into the axillae and the mediastinum. NERVE SUPPLY Branches from the 4th, 5th and 6th thoracic nerve  BREAST CHANGES AFTER CONCEPTION Breast changes during pregnancy is due to mi lk ducts growing. Breasts develop and enlarge under the influence of the hormone oestrogen. Increased blood supply during pregnancy ma kes the veins more noticeable.  BREAST CHANGES After Conception Breast often feel tender, swollen and 'fuller'. Woman might experience tingling sensations by about 12 weeks of the pregnancy. The skin of the nipple and areola may start to darken. Skin colour changes are very individual. The nipples may become more prominent. The nipple may feel quite sensitive or sore. Supportive bra are encouraged.  BREAST CHANGES During Lactation Areolas come in different sizes and colors, due to hereditary factors. Some women notice dark areolas or an increase in size with pregnancy and breastfeeding. These features usually return to pre-pregnancy appearance after breastfeeding is complete. Stages of breastmilk The first stage of milk that develops during pregnancy is called colostrum. Thick and yellow in color, colostrum lasts a few days after the baby is born. This milk is rich in protein, antibodies, vitamins and minerals. 1. Colostrum milk: traditionally used to describe the mammary secretion product during the first 4 days postpartum Stages contd… Approximately two to four days after the baby is born, transitional milk replaces colostrum 2. Transitional milk is thin and white, and contains high quantities of fat, calories, protein, lactose and vitamins. Many mothers notice the quantity and consistency of their milk changing about two to three days after their baby's birth.  Stages contd… Approximately 10 to 15 days following baby's birth, the production of mature milk begins. 3. Mature milk primarily consists of water, and it often appears bluish in color at the beginning of the feeding (foremilk and contains water, vitamins, and protein) and turns white toward the end of the feeding (hindmilk and contains higher levels of fat and is necessary for weight gain) as the milk's fat content increases. The consumption of hindmilk is essential to ensure the baby is getting adequate nutrition. Contd… A newborn's stomach is approximately the size of a marble, and the baby's stomach walls cannot stretch. The amount of colostrum produced by a mother's breasts equals the amount the baby's stomach can hold. The baby's stomach increases to roughly the size of a golf ball from seven to 10 days. PHYSIOLOGY OF THE BREAST Functions after birth of baby to produce milk. The alveoli contain milk producing acini cells. Myoepithelial surrounding acini cells contract and propel the milk out. Elastic fibre in nipple contracts and the nipple becomes erect. A tight sphincter at the end of the teat prevent unwanted loss of milk. Montgomery's glands in areola produces sebum like substances. The substances acts as a lubricant during breastfeeding.  PHYSIOLOGY OF BREAST FEEDING The alveolar epithelial cells develop into lactocytes mid-pregnancy (lactogenesis 1). They produce small quantities of specific milk components (casein and lactose) once the alveolar epithelial cells have developed into acini cells/lactocytes, around mid-pregnancy Colostrum is the first milk a breastfed baby receives. Colostrum contains high amounts of white blood cells, antibodies and immunoglobulin A. Physiology contd… It occurs around mid-pregnancy and can be detected by increased plasma concentrations of lactose and α- lactalbumin. After stage 1, the gland is sufficiently differentiated to secrete milk, but secretion is held in check by high circulating plasma concentrations of progesterone and estrogen. The secretion product, often called colostrum is extracted from breasts of pregnant women  PHYSIOLOGY OF BREAST FEEDING The immunoglobulin coats the lining of the baby’s immature intestines. The coating prevent pathogens from invading the baby’s system. High levels of progesterone inhibits most milk production.  PHYSIOLOGY OF BREAST FEEDING At birth, prolactin levels remain high even if breastfeeding is delayed for few days, lactation can still be initiated. Delivery of the placenta results in sudden drop in progesterone, estrogen, and human placental lactogen levels. Abrupt withdrawal of progesterone in the presence of high level prolactin levels stimulates the copious milk production. (Lactogenesis 2).  PHYSIOLOGY OF BREAST FEEDING Continued production of prolactin is caused by touch, as the baby feeds at the breast, Prolactin concentrations is highest during night feeds. Prolactin is involved in the suppression of ovulation. This may cause some women to remain anovular until lactation stops.  PHYSIOLOGY OF BREAST FEEDING Milk is synthesized continuously into the alveolar lumen. Milk is stored in the alveolar lumen. Oxytocin release causes the contraction of the myoepithelial cells. This Process is "Let-down or milk-ejection reflex“. Milk release is under neuro-endocrine control. Tactile stimulation of the breast also stimulates the oxytocin.  DIFFERENCES BETWEEN MALE AND FEMALE BREAST Male Breast Female Breast It is called chest or board in Predominantly comprised of lay man's language ducts, glandular epithelium Milk producing lobules are and non adipose stroma absent Milk producing lobules are Has less fat and glandular present tissue More fat and glandular Has considerably more tissue hairs Has lesser hair About 1% of males Experiences breast cancer experience breast cancer  DIFFERENCES BETWEEN MALE AND FEMALE BREAST Male Breast Female Breast The nipples tend to point The nipples point more towards the armpits. straighter ahead and Males do not experience there is considerable lactation but it can overlap. happen for various Female experiences reasons. lactation after giving They are more muscular. birth. They are less muscular Illustration of anatomy, medical: 12436234  TECHNIQUES OF BREAST FEEDING This involves positioning of Mother Her breast The baby.  TECHNIQUES OF BREAST FEEDING Mother's Positioning She seats in a way that allows the proper alignment of her back.  TECHNIQUES OF BREAST FEEDING Positioning Her Baby The mother positions the baby so that the infant's nose is opposite the mother's nipple. The baby is supported across the shoulders. The baby's head is supported by extended fingers of the mother's supporting hand If correctly attached, the baby will form a teat from the breast and the nipple. Cradle Hold Cross Cradle Hold Football Hold Source: Pintrest Football Hold for Side Lying Twins Position Source: Pintrest  ADVANTAGES OF BREASTFEEDING Advantages on Mother May serve a protective function in preventing breast cancer. Oxytocin aids in uterine involution. Reduces the cost of feeding and preparation time. Excellent opportunity to enhance a bond between mother and child.  ADVANTAGES OF BREASTFEEDING Advantages on Infant Breast milk contains secretory immunoglobulin A (IgA)  IgA binds large molecules of foreign proteins preventing absorption from GIT. Lactoferin an iron-binding protein interferes with the growth of pathogenic bacteria. Leukocytes protects against common respiratory infectious invader.  ADVANTAGES OF BREASTFEEDING Advantages on Infant Macrophages stimulates production of interferon that interfere with virus growth. Bifidus factor contains the ideal electrolytes and mineral composition for human infant growth. It is high in Lactose that digest sugar to provide ready glucose for rapid brain growth. It contain linoleic acid, an essential fatty acid for skin integrity. Prevent excessive weight gain in infant Vector.com THANK YOU