Renal 2.2 Flashcards
The biggest stimuli for the release of aldosterone is?
Angiotestin II
Why would aldosterone levels be high in a patient suffering from hypovolemie?
Hypovolemie can be due to loss of pressure in Vx or loss of NaCl. In both cases this is sensed by the appareil juxtaglomerulaire which leads to Renine secretion.
Renine leads to angiotenstine secretion (eventually converted to angiotestine II) which is the main stimuli for aldosterone production
Aldosterone is a hormone which stimulated sodium reabsorption (just like ADH). That is why you will find it in the blood;
What is Natriuresis?
Natriuresis is the process of sodium excretion in the urine through the action of the kidneys
What is a dieuretic?
A diuretic is any substance that promotes the increased production of urine. Reduce re-absorption.
What kind of hormone are prostaglandins in relation to sodium?
They are natriutic hormones as they augmentent excrétion urinaire Na et H2O au niveau du tubule collecteur -> they inhibit the reabsorption channel (ENaC)
This is beacuse they are vaso-dilators that increase cortical flow -> cortical excrètent plus facilement le sodium -> more sodium out
Why is advil a bad drug for someone with hypotension?
Advil is a COX inhibitor
COX is a precursor to prostaglandins which are vasodilator hormones
why would prostaglandins be released in response to low blood pressure when their effect is to increase excretion of sodium which ultimetly will further decrease blood pressure?
One of the most key actions of prostaglandins of the E and A series is their capacity to dilate peripheral blood vessels and thereby to lower arterial pressure. In this case it makes sense that we want to secrete more sodium
When blood pressure is low, the kidney can release prostaglandins, which can cause vasodilation to increase blood flow and decrease blood pressure. At the same time, prostaglandins can also increase sodium excretion5. While it might seem counterintuitive, this is part of a complex regulatory system. Sodium excretion can help adjust the volume of fluid in the body
What are kinines?
Vasodilatateurs très puissants
* Agmentation excrétion Na et H2O
What is Peptide natriurétique atrial (ANP)
stimulé en insuffisance cardiaque
decreases renine (thus angiotensine II), aldosterone and thus decreases reabsorption of sodium -> similar effect to prostaglandin
What does the stimualtion of sympathetic nervous system lead to?
diminue la natriurèse ( sodium excretion) -> increase sodium reabsorption in 3 ways
Stimulation de la rénine
Stimulation directe de la réabsorption tubulaire proximale de Na
Vasoconstriction préférentielle de l’artériole afférente (less filtered sodium)
What hormone would you excpect to be present in an hypertensive person and why?
ANP -> heart feels more stress so it activates ANP which is a nautritic -> decreases reabsorption of sodium
What is contraction volémique? (what does this result in)
perte de deux à trois litres de solution saline
isotonique (par exemple des pertes digestives)
contracte le volume du liquide extracellulaire
hypovolemie
this results in :
– i) La suppression du peptide natriurétique (ANP),
– ii) Stimulation sympathique
– iii) Stimulation angiotensine II
-> increase water reab
w
What is expansion de volume? (what does this result in)
Expansion de volume = higher blood pressure
heart says auh boiie -> release ANP
