BI459 Lecture Notes - Lecture 7: Adrenal Medulla, Adrenal Gland, Sympathetic Nervous System
Document Summary
Paired glands located at cranial pole of each kidney. Produce steroids hormones: medulla = inner region. Cells produce steroid hormones: large amounts of smooth er, lipid droplets. Zona glomerulosa mineralcorticoids: aldosterone; reabsorption of na+ and water in kidney. Zona fascicularis glucocorticoids: cortisol: carbohydrates, protein & lipid metabolism, stress response, regulation of immune system f(x) Composed of postganglionic sympathetic nervous system neurons modified ans ganglion. Anastomosing cords of chromaffin cells: secrete catecholamines. Main glucocorticoid: main function maintain glucose concentrations in blood, i. e. conserve glucose-derived energy stimulation of gluconeogensis, particularly in the liver. Mobilization of amino acids from extrahepatic tissues (e. g. muscle) substrates for gluconeogenesis. Inhibition of glucoses uptake in muscle and adipose tissue stimulation of fat breakdown in adipose tissue: brain has preferential access to blood glucose. During stress: anti-inflammatory and immunosuppressive properties, frequently used as drugs to treat inflammatory conditions (arthritis or dermatitis) and autoimmune diseases. Regulated by negative feedback loop pulsatile secretion of cortisol.
