Upgrade to remove ads
Only $35.99/year

Week 13 - Renal Physiology 2

Terms in this set (33)

In the proximal convoluted tubule, 95% of fluid here and 50-60% of Na
Where is the bulk of transfer done in the nephron? What % of filtered water and na is taken up?
Na is reabsorbed by active transport into tubular epithelium and creates an electrochemical gradient to drive anion reabsorption, water follows via osmosis, other solutes, now concentrated are reabsorbed by by diffussion
In the proximal convoluted tubule what are the chain of events driven reabsorption of solutes?
Drainage of the extracellular area by peritubular capillaries/vasa recta
What is key to allowing continual reabsorption of solutes?
Vasa recta are capillaries lining loop of henle in renal medulla
Difference between vasa recta and peritubular capillaries?
Sodium, the rest is absorbed secondarily via Na reabsorption
What is the only solute actively reabsorbed? HOw do the rest get in then?
By following its concentration gradient, cell is kept in low Na concentration by action of Na/K ATPase
How is sodium so readily able to move into the tubular epithelia? How is this maintained?
Enters via a membrane protein channel or a sodium glucose co-transporter that also brings in glucose
in the PROXIMAL tubule how does sodium enter the tubular epithelium from the tubule?
Co-transported with Na on SGLT, exits into interstitium via GLUT protein
How is glucose able to be reabsorbed despite the fact the tubule is low in glucose and epithelia is high? How does it get out of the cell into the interstitium>
We have a limit on the amount of glucose that can be reabsorbed, Transport maximum which is exceeded by high levels of glucose in plasma
If we can get glucose out of the urine how come diabetics have it in there?
Water, chloride, glucose, urea, AA
What substances (5) reabsorption is linked to Na reabsorption?
H due to Na/H exchanger and K due to Na/K exchanger
What two substances SECRETION is lnked to Na reabsorption and why?
Renin released by kidney converst angiotensinogen to ANGI, converted to ANGII by ACE in Lungs, This tenses the angios and stimulates aldosterone release in adrenal glands
What is the RAAS pathway?
Granular cells in afferent arteriole, fall in pressure in aff ateriole, reduction in Na/Cl at macula densa or SNS activation
What cells release RENIN to start RAAS pathway and where are they? Three key triggers of release?
Angiotensin II constricts the efferent arteriole to increase GFR when BP low and increase Na/H in proximal tubule to increase Na reabsorption, Aldosterone increase ENaC activity in collecting duct
What are the three effects Angiotensin II and Aldosterone have on the neprhon and where?
Noradrenaline constricts the afferent arteriole to maintain BP but reduces GFR, also increase Na/H activity in prox tubule to maintain water balance
What effects does the SNS have on the nephron and where/why?
Sets found in the same folder