Pharmacology /Pharm Y2S2 - Renal Part 1
Pharm Y2S2 - Renal Part 1
This deck covers key concepts related to renal physiology and pharmacology, focusing on sodium reabsorption, acid-base balance, diuretics, and kidney anatomy.
What proportion of sodium ions are reabsorbed in the proximal tubule?
Approximately 70%
Tap or swipe ↕ to flip
Swipe ←→Navigate
SSpeak
FFocus
1/30
Key Terms
Term
Definition
What proportion of sodium ions are reabsorbed in the proximal tubule?
Approximately 70%
How do sodium ions pass through the tubule epithelia?
Co-transported with organic molecules
What is the main cause of water reabsorption?
Sodium ion movement results in the reabsorption via passive diffusion
How do kidneys regulate acid-base balance?
Controlled secretion of protons and carbonic anhydrase
How do kidneys correct alkalosis?
Secretion of protons from the plasma reduces the pH, leading to a build up of carbon dioxide which is removed via the lungs
How is sodium regulated in the kidneys?
Aldosterone is released increasing the number of sodium channels in the apical membrane and sodium-potassium ATPase channels in the basolateral membra...
Related Flashcard Decks
Study Tips
- Press F to enter focus mode for distraction-free studying
- Review cards regularly to improve retention
- Try to recall the answer before flipping the card
- Share this deck with friends to study together
| Term | Definition |
|---|---|
What proportion of sodium ions are reabsorbed in the proximal tubule? | Approximately 70% |
How do sodium ions pass through the tubule epithelia? | Co-transported with organic molecules |
What is the main cause of water reabsorption? | Sodium ion movement results in the reabsorption via passive diffusion |
How do kidneys regulate acid-base balance? | Controlled secretion of protons and carbonic anhydrase |
How do kidneys correct alkalosis? | Secretion of protons from the plasma reduces the pH, leading to a build up of carbon dioxide which is removed via the lungs |
How is sodium regulated in the kidneys? | Aldosterone is released increasing the number of sodium channels in the apical membrane and sodium-potassium ATPase channels in the basolateral membrane |
Briefly describe the effect of low sodium on the RAAS? | Low sodium causes juxtaglomerular cells to release renin allowing conversion of angiotensin to angiotensin I. Kidney and lung capillaries secrete ACE allowing conversion of angiotensin I to the active form of angiotensin II. Angiotensin II stimulates release of aldosterone from the adrenal cortex. |
What is the outer region of the kidney? | Cortex |
What is the inner region of the kidney? | Medullar |
Where are the kidneys found in the body? | Lie against the back of the abdominal wall, not found in the peritoneal cavity |
What are the three major functions of the kidney? | Homeostasis Excretion Endocrine |
Describe the journey of the blood/plasma through the kidney. (4 main points) | Enters glomerulus via afferent arteriole Filtration occurs into the Bowman’s capsule before entry into the lumen of the nephron Follows proximal and straight convoluted tubules into the Loop of Henle Travels to bladder via cortical and medullar collecting ducts |
What allows glomerular filtration to occur at a reasonable rate? | Efferent arteriole is narrower than the afferent arteriole, increasing blood pressure in the glomerulus |
Where do molecules travel to if they are not filtered into the Bowman’s capsule? | Through efferent arteriole to vasa recta |
What are the three layers that plasma travels through to enter Bowman’s capsule? | Capillary endothelium Basement membrane Capsule cells (podocytes) |
How are molecules filtered into Bowman’s capsule? | Pores of 30kDa diameter act as a molecular sieve |
Why is albuminuria common in reduced GFR? | Filtration becomes less efficient, allowing larger molecules such as albumin to filter into the nephron and be excreted in urine |
What is secretion? | Movement of molecules from the vasa recta peritubular capillary into tubules |
What is reabsorption? | Movement of molecules from tubules back into peritubular capillaries. Generally small molecules such as glucose and amino acids |
Under what circumstances can molecules not be filtered? | If they are bound to plasma proteins |
What are diuretics? | Compounds that increase excretion of sodium and water |
Why are diuretics used in cardiac failure? | Increase in interstitial fluid volume with reduced cardiac output, increases venous pressure. By reducing fluid volume, blood pressure is reduced, reducing cardiac workload. |
Why are diuretics used in hyperaldosteronism? | Increased sodium retention causes increase in plasma volume raising blood pressure. Diuretics promote excretion of excess sodium |
What is the action of loop diuretics? | Inhibit the Na/K/Cl carrier in the ascending loop of henle |
Give examples of loop diuretics. | Furosemide | Bumetanide |
Why is there a risk of alkalosis with loop diuretics? | Carbonic acid excretion is not affected, increasing the plasma concentration thus raising pH |
What effects do loop diuretics have on small molecule concentrations? | Increased excretion of magnesium and calcium | Reduced secretion of uric acid |
What is the effect of loop and thiazide diuretics on proton concentrations? | Na/H exchanger is not affected thus entry of sodium drives the excretion of protons |
Why is hypokalaemia a common side effect of diuretics? | The K/Cl transporter is blocked, reducing uptake of these ions from the tubule |
What is the mechanism of action of thiazide like diuretics? | Inhibit the Na/Cl co-transporter in the distal tubule |