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MCB 135E: Discussion. Discussion Topics. Lactation Gastrointestinal System Liver. Lactation. Mammary Gland Development Milk Production, Ejection, Cessation Benefits of Breast Feeding. Mammary Gland Development. 6 th week of gestation Formation of mammary ridges
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Discussion Topics • Lactation • Gastrointestinal System • Liver
Lactation • Mammary Gland Development • Milk Production, Ejection, Cessation • Benefits of Breast Feeding
Mammary Gland Development • 6th week of gestation • Formation of mammary ridges • Further development under influence of E (pre-natal) • Female breasts develop further at puberty • Again primarily under influence of E • Enlargement due to fat deposits and connective tissue • Further growth and branching of ductal system
Mammary Gland: Pregnancy • Higher levels of E lead to more ductal elongation • Influenced also by GH, PRL, Insulin, and glucocorticoids • Final development of gland due to influence of P • Causes branching and formation of alveoli buds at ends of ducts • Alveoli are lined with milk secreting epithelium
Infant Reduction in infections Initial increased growth Decreased obesity in adulthood Positive effects on mental development Mother More rapid and sustained weight loss Lactational amenorrhea Decreased Breast Cancer ? Psychological benefits Benefits of Breast Feeding
G.I. System • GI Functions • Digestion and Absorption • Defense • Endocrine • Mechanical and Chemical • Nutrition of the Infant
G.I. System Development • Smaller size = Shorter duration of food in GI • Developing Stomach • Spitting, Regurgitating, burping are a result of peristalic waves in opposite direction • Emptying time • First Month – 1-4 Hours • Adult – 5-6 Hours • Size (Volume) much smaller at birth with continual increase in size until adulthood
Proteins Synthesized in alveolar cells Casein and lactalbumin are predominant proteins Have antigenic properties Vitamins No supplements required for infant while breast feeding Minerals Mother needs to take calcium supplements Fats (Breast Milk) High in essential FA required for brain and retina development Secreted in droplets pinched off from cell into alveolus CHO Lactose Glucose Galactose Nutrition
Liver • Functions • Formation of Bile • CHO storage • Formation of Urea • Cholesterol Metabolism • Make plasma proteins • Regulates fat metabolism • Metabolizes some polypeptide hormones • Reduction and conjugation of steroid hormones • Vitamin D3 metabolism • Detoxification
Functions Emulsification of lipids Activation of enzymes for digestion of lipids Conjugation of bilirubin to form a water soluble product for excretion Excretion of cholesterol Excretion of drugs, heavy metals, and environmental toxins Neutralization of acid delivered to duodenum from stomach Constituents Water (97%) Bile Salts Bile Pigments (Bilirubin and Biliverdin) Cholesterol Inorganic Salts Fatty Acids Lecithin Bile