UNIT 2

• Lactation - is the production and secretion of breast milk for the purpose of nourishing an infant
• lactogenesis - production of milk
• Colostrum - thin yellowish fluid secreted by the mammary gland during the first few days of parturition, before the formation of the true milk
• Foremilk - milk secreted at the beginning of one nursing period, Clear and thicker than hindmilk (concentrated)
• Hindmilk - milk secreted at the end of one nursing period, Medyo liquidy
• Colostrum

  • The first milk
  • Formed during lactogenesis II
  • Contains high concentrations of antibodies
  • Also a laxative, which initially cleans out the baby’s digestive organs
• Left - colostrum 

  Right - foremilk/hindmilk
• Alveoli - produces milk
• Oxytocin - makes muscle cells contract to produce milk
• Mammary glands - glands of the female breast that synthesize milk
• Alveoli - a rounded or oblong shaped cavity present in the breast
• Secretory cells - cells in the acinus (milk gland) that are responsible for secreting milk components in the ducts
• Myoepithelial cells - specialized cells that line the alveoli and that can contract milk to be secreted into the duct.
•  mammary alveolus (plural: alveoli, from Latin alveolus, "little cavity")
• Development of the mammary gland - starts in puberty when ovaries mature
• Lactogenesis 1 - Formation of milk
• Lactogenesis 2 - The milk already comes in
• Lactogenesis 3 - milk composition becomes stable
• Prolactin - acts on the mammary glands to promote the production of milk
• Oxytocin - hormone that stimulates the mammary glands to eject milk during lactation and the uterus to contract during childbirth
• Let-down reflex - the reflex that forces milk to the front of the breast when the infant begins to nurse
• Terminal end buds (TEBs) are highly proliferative structures at the ends of elongating lactiferous ducts
• Estrogen and progesterone - hormones from the ovary and placenta stimulate breast development during pregnancy
• Lactation process - The establishment of lactation consists of a complex neuroendocrine control mechanism
• Everytime breast is empty = prolactin is released = it will be maintained once breastfeeding is continuous
• The physiological needs of lactation are greater than those of pregnancy
• Average daily milk production of 750 ml for the first 6 months and 600 ml for the second 6 months.
• Energy - additional 500 kcal per day energy intake for lactating
• The average energy content of human milk is about 70 kcal/ 100 ml
• Protein -  additional 27 grams of protein during lactation (89)
• Fat -  provide about 20 to 35% of total calories
• Water and other Fluids

  • About 87% of the volume of breastmilk is water.
  • An additional intake of 750 - 1000 ml of water per day is recommended
• Vitamin A - Most infants have Vitamin A stored in the liver at birth. This comes from the mother’s diet during pregnancy ( additional 400 ug RE in the first year of lactation)
• Vitamin C - increase of 35 mg per day is recommended in order to maintain a good level of Vitamin C
• Thiamin, Riboflavin and Niacin - The increase of 0.2 mg, 0.6 mg, and 4 mg NE/day
• Folate - additional allowance of 150 ug per day takes care of the folate content in breast milk
• Vitamin D - supplementation will be necessary if maternal intake is poor or if infants receive little sunshine exposure
• Iron - addition of 2 mg
• Iodine - Additional 100 mcg/day due to iodine content in breast milk and its role in basal metabolism, prevent goiter
• Zinc - breastmilk contains 2.6 mg/L. Extra intake of 6.7 mg/day is recommended