Endocrine System
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Adrenal Glands – Production Control, List The Actions And Major Disorders
Adrenal glands are a pair of yellowish flat pyramid like glands which lie at the upper end of the kidneys. They look like a cap on the kidney and each gland has an outer yello adrenal cortex and inner reddish-brown adrenal medulla. Adrenal medulla secretes two harmones
Parathyroid Hormone and Calcitonin
Plasma calcium levels are regulated by the polypeptides parathyroid hormone and calcitonin. Parathyroid hormone, secreted by the parathyroid glands embedded in the thyroid, acts to increase plasma calcium levels. Parathyroid hormone also decreases plasma PO4. Calcitonin, secreted from the parafollicular cells of the thyroid, acts to decrease
Structure of Mammary Glands and Breasts
Both males and females possess mammary glands. The mammary glands of males and immature females are similar. At puberty, estrogens and progesterone stimulate the development of female mammary glands. Estrogens start breast and mammary gland development, and progesterone stimulates the maturation of the mammary glands so that
Lactation – The Control of Lactation and Milk Ejection
High blood levels of estrogens and progesterone during pregnancy stimulate the development of the mammary glands and enlargement of the breasts in preparation for milk secretion, or lactation (lak-ta’-shun). Although the mammary glands are capable of secreting milk, the high levels of estrogens and progesterone inhibit the
