Nutrition Therapy for Renal Disorders肾脏疾病的医学营养治疗课件.ppt

Medical Nutrition Therapy for Renal Disorders Functions of the Kidney Excretory Acid-base balance Endocrine Fluid and electrolyte balance Excretory Functions Removal of excess fluid and waste products 180 L of filtrate pass through the kidneys each day ? producing 1-2 L of urine Wastes excreted from the body in urine include urea (byproduct of protein metabolism); excess vitamins and minerals; metabolites of some drugs and poisons Acid-Base Functions Acid-base balance is maintained through a buffer system, which maintains blood at pH of 7.4 Bicarbonate carries hydrogen ions to the kidneys where they are removed from extracellular fluid in the tubules, returned to the bloodstream as needed Phosphate buffers intracellular fluid Acid-Base Balance Functions When fluid volume is low, anti-diuretic hormone (ADH) or vasopressin is released from the anterior pituitary; increases absorption of water in the collecting duct When extracellular volume (ECV) decreases, the renin-angiotensin-aldosterone system is activated ? excretes less sodium chloride Endocrine Functions 1,25-dihydroxy-vitamin D3 or calcitriol is produced in the kidney; enhances calcium absorption Activation of Vitamin D and excretion of excess phosphate maintain healthy bones Erythropoietin: acts on the bone marrow to increase production of red blood cells The Nephron The Most Common Kidney Diseases Diabetic Nephropathy damage to the nephrons in the kidneys from unused sugar in the blood, usually due to Diabetes. High Blood Pressure can damage the small blood vessels in the kidneys.? The damaged vessels cannot filter poison from the blood as they are supposed to. Polycystic Kidney Disease (PKD) is a hereditary kidney disease in which many cysts grow in the kidneys.? These cysts may lead to kidney failure. The Most Common Kidney Diseases Acute Renal Failure - Sudden kidney failure caused by blood loss, drugs or poisons.? If the kidneys are not seriously damaged, acute renal failure may be reversed. Chron