Fichas
BMS11-1035 Kidney Function II: Production of concentrated urine by the kidney
Fichas del conjunto (24)
- 1Proximal Tubule Na+ Reabsorption - Na+ moves into cell via ...exchanger and ...symporter - ...maintains low Na+ in cell - negative charge on lumen repels Cl-, HCO3- etc.1. Na+/H+
2. Na+/nutrient (Glucose, AA etc.)
3. Na+/K+ ATPase - 2Thick Ascending Limb Na+ Reabsorption - ... cotransporter to transport Na+ - ... maintains low Na+ in cell - K+ channels allow K+ out into filtrate, creating ... and driving Na+ into cell1. Na+/K+/2Cl-
2. Na+/K+ ATPase
3. positive charge - 3Distal Tubule Na+ Reabsorption - cotransporter transports Na+ in - ... keeps Na+ concentration in cell low1. Na+/Cl-
2. Na+/K+ ATPase - 4Collecting Duct Na+ Reabsorption -2 cell types: ... cells (Na+), ...cells (H+) - In ... cell, ....and Na+/K+ ATPase1. Principle
2. Intercalated
3. Principle
4. Na+ channels - 5What is the definition of clearance? What is the equation? What is the unit?1. The volume of plasma cleared of a substance in a given time
2. C=(ion concentraton in urine*volume of urine)/ion concentration in plasma
3. mL/min - 6Clearance Values: ...: <120ml/min eg. most solutes No change: .../min eg. ... ...:>120ml/min eg. ...1. Reabsorption
2. 120, inulin
3. Secretion, PAH - 7Describe the mechanisms of ADH in the collecting duct1. ADH binds to V2
2. Activates G protein/adenylyl cyclase
3. PKA causes translocation of AQP2 to membrane
4. H20 can enter via aquaporins - 8H20 Reabsorption depends on which 3 factors?1. Osmosis
2. Sodium reabsorption (bc H20 reabsorption coupled with Na+, bulk flow)
3. Tubule permeability
- increased by AQP1/tight junctions on membrane - 9Making Concentrated Urine How is the concentration gradient created? 1. ...pumps Na+ out via Na+/K+/2Cl- co transporterThick ascending limb
- 10Making concentrated urine How is water removed from the LoH? 2. ... picks up ..., loses ... (osmosis) as it descends due to increasing solute concentration down the medulla1. Descending limb
2. Na+
3. H20 - 11Making concentrated urine Why does osmolarity decrease up the ascending tubule? 3. ... impermeable to H20 - solutes move out, H20 remains - Osmolarity decreases up ascending tubeThin ascending limb
- 12Name the 3 places of urea reabsorption and their mechanism?1. Proximal Tubule-passive reabsorption
2. LoH- apical secretion via VTA2
3. Inner Medullary Collecting Duct- Reabsorbed into cell via VTA1 and leaves cell into interstitium via VTA3 - 13Osmolality Ranges: Plasma: ...mosm/kg Urine: ...mosm/kg Concentrated if >plasma Dilute if1. 285-295
2. 50-1400
3. Sodium - 14Potassium is the major ... in body, determines ...1. Intracellular cation
2. Resting membrane potential - 15What is Renal Plasma flow? What is it measured by? What is it usually?1. Amount of blood to kidneys/time
2. PAH because no reabsorption
3. Usually 600mL/min - 16What is the equation for renal blood flow?Plasma flow- (1-haematocrit aka RBC proportion)
= 600/0.55 - 17Sodium reabsorption occurs in: PCT (...%) Thick Ascending Limb (...%) DCT (...%) Collecting Duct (...%)1. PCT: 65
2. Thick Ascending Limb of LoH: 25
3. DCT: 2-5
4. CD: 5 - 18What are the 4 factors increasing K+ secretion?1. Na+ entry through Na+ channels
2. Aldosterone, which stimulates K+/Na+ channels
3. High tubular flow rate
4. Alkalosis, which enhances K+ movement - 19What are the sites of K+ reabsorption?1. Thick ascending limb via Na+/K+/2Cl- cotransporter
2. Distal tubule via K+/H+ exchanger
3. In CD by intercalated cells with K+ channels or K+/Cl- cotransporter
- outweight by principal cell K+ secretion - 20Principle cells reabsorb ... and secrete...Na+
K+ - 21What is the role of ADH in urea recycling?ADH increases water permeability but not urea permeability in outer medullary/cortical collecting ducts, allowing urea to concentrate in the tube
As a result, there is a concentration gradient of urea created within the tube, driving urea reabsorption later on in the inner medullary collecting duct - 22What measures clearance experimentally vs. clinically?Experimentally: inulin
Clinically: creatinine - 23... supplies blood without washing gradient away via counter current exchange Counter current exchange is when loops slow blood flow so reabsorbed solutes can reenter interstitual fluid/mantian concentration gradientVasa Recta
- 24Urea is .... at the level of the renal corpuscle and undergoes ... in the kidney as majority is1. Freely Filtered
2. Recycling
3. Reabsorbed
Información
- Descripción
- Define osmolality and its importance to renal function. Describe the processes of salt and water absorption throughout the nephron. Describe the mechanism of production of concentrated urine. Describe the counter-current mechanism. Describe the recycling of urea. Explain the role of ADH in collecting duct. Describe the renal handling of Ca2+, Mg2+, phosphate and potassium.
- Creado por
- Evian Chai · abr 2020
- Actualizado
- 23 abr 2020
- Visitas
- 20
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