Kidneys Study Notes

-Regulation of water and salt balance -Removal of metabolic waste and foreign What are the main functions of the kidchemicals neys? -Gluconeogenesis (Glucose formation) -Hormone secretion (e.g. erythropoietin) What is the outside protective layer of the kidney called? Capsule Cortex and Medulla What two parts of the kidney do nephrons sit in? What is the role of the glomerulus? filtration -Cells in the Bowman's capsule in the kidneys that wrap around capillaries of the glomerulus -To prevent larger proteins and cells from leaving What are podocytes? What part of the nephron comes before the collecting duct? Distal convoluted tubule (DCT) Where does the collecting duct lead into? Ureter What is the name of the blood vessel that takes blood away from the glomerulus? Efferent arteriole What is the name of the blood vessel that Afferent arteriole (AFOREMENTIONED) brings blood into the glomerulus? What is glomerular filtration rate? 1/4 Volume filtered from both glomeruli per unit of time -Dilate efferent -Constrict afferent -Reducing pressure in glomerulus How does the body reduce the glomerular filtration rate? -Constrict efferent How does the body increase glomerular -Dilate afferent filtration rate? -Increasing pressure in the glomerulus Can large proteins pass through the glomelerus? No, they're too big to fit ;) Can glucose pass through the glomelerus? Yes -Co-transport -Counter-transport (e.g. Na+ in and H+ out) In the PCT, what are the two ways in which Sodium is reabsorbed into the tubule cells? -Active transport (using ATP) -Sodium potassium pump (like in nerve cells) How do the reabsorbed Na+ ions get transported into the interstitial space from the tubule cells? What part of the Loop of Henle is responsible for ion uptake? Ascending limb Co-Trasnport with pottasium How do sodium and chlorine get absorbed in the ascending limb? 2/4 How does chlorine move from tubule cells to areas surrounding the descending limb? Facilitated diffusion Sodium pottasium pumps How does sodium move from tubule cells to areas surrounding the descending limbs (interstitial space)? How does sodium move from tubule to collecting duct cells? Facillitated diffusion How do sodium ions move from the collecting duct cells to the interstitial space? Sodium pottasium pumps How does aldosterone work? -Increases (gene) expression of ion channels -Increases Na+ reabsorption Where is water mostly reabsorbed in the kidney? Descending limb -Increases ion concentration in the interHow does the ascending limb aid water stitial space reabsorption? -Creating a hypertonic solution In what direction does blood flow around Countercurrent (maintains concentration the Loop of Henle? gradient) What is the name of the type of water channels that are found in the collecting duct? Aquaporins How does vasopressin work? -Acts on receptors on collecting ducts cells -Causes aquaporin-rich vesicles to fuse with cell membrane -Increases the number of channels -Increasing water reabsorption What is the term used for high amounts of protein in the urine? Proteinuria 3/4 What is the enzyme involved in pH regulation of the body? Carbonic Anhydrase How do the kidneys regulate pH? By reabsorbing HCO3- it will decrease pH What is glutamine used for in the kidneys? -Metabolised into ammonium ions and carbonate ions -Carbonate ions reabsorbed into blood to reduce pH What is the term for when the body loses H+ ions and becomes more alkali? Alkalosis What is the term for when the body gains H+ ions and becomes more acidosis? Acidosis What is the body's responses to acidosis? -H+ secreted into tubules -All HCO3- reabsorbed -Glutamine metabolism enhanced so that more HCO3- generated In what form are H+ ions secreted? -NH4+ (ammonium) -H2CO3 (carbonic acid) -Excess HCO3- excreted and not reabsorbed What is the bodys response to alkalosis? -Glutamine metabolism decreased -H+ ions secreted into tubules Are ionised or unionised drugs more water soluble and therefore excreted more? Ionised -Makes urine pH very high (alkaline) Why is sodium bicarbonate given in pa- -Making active ingredient (salicylic acid) tients with aspirin poisoning? ionised and more water soluble -Meaning it is excreted quicker 4/4