Renal 2.1 Flashcards
What is the minimal and maximal quantity of milliosmole that must be in the urine?
Minimal : 50milliosmoles/litre
Maximalle 1200milliosmoles/litre
What is the minimum amount of water you have to drink ?
Becasue we must secrete 900 milliosmoles each day and the maximum concentration is 1200,
we must at least drink 750ml of water
Would a patient that is drinking 10L of water survive if he only eats 400milliosmoles of salt?
No, he will be in danger because he can only urinate 8L of his urine at minimum (50millosmole/L). All the extra water will be forcefully reabsorbed -> hyponatrémie (lower plasmatic osmolarity)
What is the role of the vasa recta in the kidneys?
They assure that the interstetion of the kidneys is hypertonic by absorbing the water as it is secreted
What is the mechanism for urine dilution?
La réabsorption active
de chlorure de sodium
mais sans eau dans la
branche ascendante de
l’anse de Henle
(imperméable à l’eau)
est le segment diluteur
processus qui
diminue l’osmolalité du
liquide tubulaire à 200
milliosmoles/kg à la fin
de la partie médullaire
et jusqu’à 100
milliosmoles/kg à la fin
de la partie corticale en
augmentant celle de
l’interstice médullaire
What is excercion fractionelle?
The % of a molecule that will be secreted
For example for sodium 99% will be reabsorbed and so:
excercion fractionelle= <1%
You receive a urine sample with a high sodium concentration (450mmol/jour) from a patient suffering from hypertension. What is the recomendation?
The patient’s blood pressure is due to the high sodium diet. He simply has to reduce sodium input becasue the kidney is not able to filter it and so it is going to his blood.
Where is 65% of sodium reabsorbed? What follows this?
Tubule proximal
Via l’échangeur Na/H électroneutre (actif)
Via le cotransport du sodium avec le glucose
This generates a negative potential in the intertistial space
This allows for Cl- to be pushed towards the capillary side
THe movement of Cl- creates a +-vely charged interstitial space which will then allow for other + charged ions to pass (K+, Ca2+ etc)
- La réabsorption d’eau suit passivement celle
des électrolytes;
What is the transporter that allows for the active reabsorption of Na+ in the anse ascendante? What % does this cover?
Symport Na+ 2Cl- K+
25% of sodium
Manipulation rénale du sodium Tubule distal, type of channel and %?
A symport (Na+ Cl-)
around 5%
Manipulation rénale du sodium Tubule collecteur. Channel, why is it special and %?
Channel here is the ENaC. This is the area where the fine tuning occurs. I.e., to absorb or exrete sodium
This channel is sensitive to: Aldosterone, ADH and prostaglandines and can be inhibited or activated as required by the organism
very low % (1% or so). this is the fine tuned re-absorption
What is the role of dieuretics and what is their main target?
Diurétiques-> increase volume of urine
anti-Diurétiques (ADH) increase reabsorption of water
the main target is :
diminuer la réabsorption du sodium et par conséquent augmenter
l’excrétion urinaire de sodium et d’eau
You recieve a patient with diuretic prescription but you are not sure where this dieuretic acts. However, looking at his urine sample you notice decreased K+ concentrations. What is this dieretic, where does it act?
This is a dieretic that acts on the ENaC at the tube collecteur.
This is because under normal conditions the re-absorption of Na+ creates a negative (-) interstitiel potential ce qui attire les K+ (elimination de K+)
You recieve a patient with diuretic prescription but you are not sure where this dieuretic acts. However, looking at his urine sample you notice increased Na+ concentrations. What is this dieretic, where does it act?
This is a diuretic that acts on the Na-K-2Cl
at the anse ascendante de henle
les plus
puissants diurétiques
You recieve a patient with diuretic prescription but you are not sure where this dieuretic acts. However, looking at his urine sample you notice INCREASED K+ concentrations. What is this dieretic, where does it act?
Au niveau du tubule proximal,
diuretics used here increase urinary excretion of bicarbonate, sodium and potassium.
