Adrenal Gland PDF

13/11/23 Adrenal gland: Learning objective: describe the biosynthesis and regulation of adrenal hormones. Learning objective: understand the role of the adrenal gland in response to stress. Learning objective: learn about the physiological and metabolic effects of adrenal hormones. Learning objectiv...

13/11/23 Adrenal gland: Learning objective: describe the biosynthesis and regulation of adrenal hormones. Learning objective: understand the role of the adrenal gland in response to stress. Learning objective: learn about the physiological and metabolic effects of adrenal hormones. Learning objective: understand the effects of over, and under production of adrenal hormones. Anatomy of the adrenal glands: They are located above the kidneys. They aren’t connected to the kidneys; connective tissue hold them above the kidneys. I Arterial supply: Inferior phrenic artery ( superior supra renal artery ). d drainage 1 drainage Aorta ( middle supra renal artery ). Renal artery ( inferior supra renal artery ). Arteries in red branchingone Further blood supply of the Adrenal gland: 3 layers of the cortex: We swabYGrief Zona glomerulosa. capillaries Zona fasciculata. sinusoids Zona reticularis. of Histology of the Adrenal gland: Zona glomerulosa produces aldosterone. Zona fasciculata produces cortisol. Zona reticularis produces androgens. Medulla produces adrenaline and nor-adrenaline. Mineralocorticoids ( Aldosterone): Biosynthesis of Aldosterone: This occurs in the cells of the Zona glomerulosa. Angiotensin II binds to a membrane surface receptor on the cell. Through protein kinase C and calcium, promotes the conversion of cholesterol into pregnenolone. The cholesterol ester ( in diagram ) enters the mitochondria and is converted into aldosterone through a series of steps. Cholesterol ester Pregnenolone 2 Progesterone 3 1 172 hydrolase corticosterone deoxy 2 38HSD corticosterone 3 21 hydroxylase signifffastest Aldosterone Disease of the Adrenal glands: 1. Hormonal over-production: Zona glomerulosa: mineralocorticoid excess ( Conn’s syndrome ). Zona fasciculata: glucocorticoid excess ( Cushing’s syndrome). 2. Hormonal underproduction: Primary: Addison’s disease. Secondary: Hypopituitarism. Primary Hyperaldosteronism: Too much aldosterone can cause: Hypertension. Hypokalaemia. loss of k effect of aldosterone Metabolic alkalosis. Cortisol ( Glucocorticoid ): Pregnenolone h Hydroxypregnenolone z this when begins ACTH binds to on 17 a Zona Hydroxyprogesterone receptor cell in fascialata 3 deadlycortisol Contigo When does the body produce cortisol: Stressed. Severe infection. Trauma. Burns. Illness and surgery. É glycosylase 3 21 hydroxylase 4 11 B hydroxylase Actions of cortisol: Adrenal androgens: The main adrenal androgens are: Dehydroepiandrosterone ( DHEA ). Androstenedione. Pregnenolone 17 hydroxypregnenolone Z Denyoroepi androsterone 3 1 2 172 17 20 3 3B HSD Androstenedione hydroxylase lyase Hormones of the adrenal medulla: catecholamines In the presence of stress there is sympathetic simulation. This leads to the stimulation of the adrenal medullary cells, which then release adrenaline and noradrenaline into the bloodstream. Biosynthesis and release of Catecholamines: tyrosine tyrosine 2 Dopa 3 B 4 N hydroxylase decarboxylase hydroxylase methyltransferase Dopamine Levodopa 7 Noradrenaline y Adrenaline Actions of Catecholamines: Mobilisation of glycogen reserves. Breakdown of glycogen into glucose. Breakdown of fats to fatty acids. Increases the rate and force of cardiac muscle contraction. Enables the bodies to do with physical and physiological stress. Hypersecretion d Adrenal medullary Hormones Pheochromocytoma I