BREAST
l.Located in the upper anterior aspect of chest
2. Mammary gland is a compound alveolar gland consisting of I5 to 20 lobes of glandular tissue separated from each other by interlobular septa. A lactiferous duct that opens on the tip of the nipple drains each lobe. The mammary gland secretes milk used for nourishment of the infant.
Development: During puberty; estrogen from the ovary stimulate growth and development of the duct system. During pregnancy progesterone secreted by the corpus luteum and placenta acts synergistic-ally with estrogen to bring the alveoli to complete development. Following parturition, prolactin (lutetrophin) in conjunction with adrenal corticoids initiates lactation and oxytocin from the posterior pituitary induces ejection of milk. Sucking or milking reflex, stimulates milk secretion and discharge of milk.
CHANGES IN PREGNANCY:
First 6 to 12 weeks there are fullness and tenderness,erectile tissues develop in nipple, nodules are full. The pigment is deposited all around the nipple (primary areola) and nipples become black and projected and a few drops of fluid may be squeezed out. In the next 16 to 20 weeks, the secondary areola shows small whitish spots of pigmentation due to hypertrophy of the sebaceous glands, the so-called glands of montgomery.
MILK
A secretion ol‘ mammary glands for feeding the young. The constituent food substances vary hum animal to animal.
Composition
Milk from cow consists of water,organic substances and mineral salts.
The principal proteins are caseinogen. ions of lacto alburnin. and lacto globulin. In the presence of calcium ion the insoluble. caseinogen is converted into soluble Casein,by the action of acids,renin. or pepsin. This caseinogen brings about the curdling of milk Lactoglobulin is identical with serum globulin of blood and hence contains maternal antibodies.
Carbohydrates Lactose or milk sugar is the principal sugar, although small quantities of other sugars are present.
Fat : The principal fats are glycerides of oleic, palmitic and myristic acids. Smaller quantities of stearic acid and short chain fatty acids, with carbon chains of C4to C24. are present. Sterols, phospholipids lecithin and cephalic acid are also present. Churning causes the fat globules to unite into a solid mass and separate from the whay to form butter.
Mineral salts: The principal cations are calcium. potassium, and sodium. the principal anions are phosphate and chloride, citrates and lactates are present in small quantities. Mill: is low in iron and magnesium.
Vitamins: Vitamin A and those of the B complex (thiamine, riboflavin and pantothenie acid) are present in adequate quantities to meet the needs of a growing child; milk is low in vitamin C and D.