Busy. Please wait.
or

show password
Forgot Password?

Don't have an account?  Sign up 
or

Username is available taken
show password

why


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.


Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Don't know
Know
remaining cards
Save
0:01
To flip the current card, click it or press the Spacebar key.  To move the current card to one of the three colored boxes, click on the box.  You may also press the UP ARROW key to move the card to the "Know" box, the DOWN ARROW key to move the card to the "Don't know" box, or the RIGHT ARROW key to move the card to the Remaining box.  You may also click on the card displayed in any of the three boxes to bring that card back to the center.

Pass complete!

"Know" box contains:
Time elapsed:
Retries:
restart all cards
share
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

Phys3 Na,Cl, & H2O

Phys3 Renal Transport of Na,Cl, & H2O

QuestionAnswer
Describe the reabsorption of Na, Cl, and Water ALL are freely filtered & 99% reabsorbed. 1.Na: para & transcellular. 2.Cl: para & transcellular (follows Na+). 3.H2O: Osmosis & secondary to solute reabsorption.
Big picture of Na+ regulation Where Na+ goes H2O goes. Therefore Na regulates volume and thus BP.
How does Na cross the apical membrane? 1.Na/H Antiporter (primary method). 2.Co-transport with nutrients. 3.Co-transport with phosphate/sulfate/organic. **some solvent drag along w/ paracellular route.
How does Na cross the basolateral membrane? 1.Na/K ATPase. 2.Na/HCO3- symporter **HCO3- is primary anion reabsorbed with Na+
What happens to Bicarbonate as you progress through the Proximal tubule? [HCO3-] decreases because it is being reabsorbed with Na+
Role of carbonic Anhydrase (CA) in Na+ reabsorption in proximal tubule? Catalyzes CO2+H2O in renal tubule cell for: 1.H+ ions to drive the apical Na/H antiporter. 2.HCO3- to drive the basolateral Na/HCO3- symporter.
What would happen if CA reaction was inhibited? 1.Dec Na uptake. 2.Dec HCO3- uptake. 3.Diuresis (Dec water reabsorption thus Dec BV).
Osmotic diuresis Occurs if there is a high concentration of a solute (X) in the glomerular filtrate that doesn't get reabsorbed. Causes: 1.Dec H2O reabsorption. 2.Inc tubule H2O, but Dec tubule [Na+]. 3.Creates passive diffusion (paracellular) of Na back into tubule.
Is H2O permeable in the Proximal Tubule YES, VERY permeable, undergoes Isosmotic reabsorption.
When might you see Osmotic diuresis? Diabetes Mellitus. The excess glucose exceeds the Tm and stays in the tubule causing H2O to remain in the tubule.
Which is absorbed more in the loop of henle: NaCl or Water? NaCl
Reabsorption in Loop of Henle: Descending thin limb Water gets reabsorbed. NaCl does NOT! **Concentrates NaCl in the tubule at the bottom of the loop.
Reabsorption in Loop of Henle: Ascending thin limb NaCl is reabsorbed (via passive paracellular reabsorption), Water is NOT!
Reabsorption in Loop of Henle: Ascending thick limb NaCl is reabsorbed (actively & passively), water is NOT! **called the DILUTING SEGMENT
Important transporter in the Thick Ascending Loop (dilution segement) Na/K/2Cl symporter. (Lumenal K+ channels let K+ back in so it doesn't limit the process) **Also the target of "loop diuretics" (Furosemide & bumetanide).
What drives K+, Ca+, & Mg+ from the Lumen into the interstitium? Lumen Positive Voltage.
Is the fluid presented to the distal convoluted tubule Hypo or Hyperosmotic? HYPOSMOTIC.
Major transporter in the Distal Convoluted Tubule (DCT) Na/Cl co-transporter (symporter). **Target of thiazide diuretics.
Is water permeable in the DCT? No, makes the hyposmotic fluid it receives even MORE hyposmotic.
What type of fluid does the Cortical Collecting Duct (CCD) receive? VERY hyposmotic.
What Channels are very important in the CCD apical membrane? ENaC channels: allow Na movement out of the lumen. **regulated by Aldosterone.
What CCD cells have ENaC's? what hormone regulates these channels? Principal cells. Aldosterone.
What CCD cells have Aquaporin channels? what do they do? what stimulates them? 1.Principal cells. 2.Allow Water reabsorption. 3.ADH.
What are the two main effect's seen with aldosterone on principal cells' ENaCs? 1.Inc Na reabsorption. 2.Inc K+ secretion.
What Diuretic blocks ENaCs in Principal cells? Amiloride
With ADH, water permeability (mainly in the the CCD) is? Characterize the fluid leaving the CCD entering the ureters? HIGH. Fluid is concentrated b/c water will move out of the lumen into the interstitium (Isosmotic in CCD, Hyperosmotic in IMCD).
WITHOUT ADH, water permeability (mainly in the CCD) is? Characterize the fluid leaving the CCD entering the ureters? LOW. The fluid is dilute (hyposmotic). **Water Diuresis
What happens to the osmolality moving from the medulla to the papilla (towards the calyx)? It becomes more HYPERosmotic.
Does ADH affect Na reabsorption? INCREASES in the thick ascending loop & CCD
What are the ADH levels with Diabetes Insipidous? LOW ADH which causes: 1.Polyuria. 2.Polydipsia. **Same as diabetes melitis
Created by: WeeG