NUTR 214 Lecture Notes - Lecture 21: Zona Fasciculata, Zona Glomerulosa, Zona Reticularis

• School: McGill University
• Department: Nutrition and Dietetics
• Course: NUTR 214
• Professor: Arne Kislenko

Document Summary

3 morphological and functionally different layers: zona glomerulosa; mostly mineralocorticoids (aldosterone, contains 18-hydroxylase, does not contain 17a-hydroxylase, thus no production of glucocorticoids, zona fasciculata; produces mainly glucocorticoids (cortisol, zona reticularis; glucocorticoids, progestins, androgens, estrogens. -> the synthesis of adrenal steroids is controlled by pituitary hormone adrenocorticotropin (acth) Aldosterone: sodium metabolism/regulation - increases the reabsorption of na+ by the kidney, affects the plasma concentration of k+ and h, loss of k+ and h+ in urine balances the reabsorption of na+ Control of glucocorticoid secretion: controlled by pituitary adrenocorticotropin (acth), a 39 amino acid polypeptide, synthesized as part of larger protein known as proopiomelanocortin (pomc, feedback control of cortisol secretion is via hypothalamus and anterior pituitary. In cases of enzyme deficiencies (such as lack of 11b-hydroxylase) where cortisol is not produced , acth secretion is unchecked: congenital adrenal hyperplasia, treatment: administration of cortisol, which corrects deficiency and normalizes the acth secretion.