Renal 1.2 Flashcards
What are some things that will never be found in the filtrate?
Pas de globule rouges
Pas de plaquettes
Pas de globules blanc
No proteins
La pression ______________différentielle représente la différence de pression entre le capillaire glomérulaire et l’espace urinaire de Bowman. elle est de?
hydrostatique
50 - 15 = 35 mm Hg
What is the oncotique pressure in the espace de bowman?
Nada
Il n’y a pas de pression oncotique dans l’espace de Bowman en
l’absence de protéines dans l’ultrafiltrat glomérulaire.
What happens to the pression oncotique as you go from arteriolle afferente to efferente? Why is this important?
It increases all the way to 35mmHg
You filter water and otehr molecules but keep proteins
as such once you are at the efferent part you really want to reabsorb water
Becasue the hydrostatique pressure is 35mmHg and now the oncotique pressure is the same i.e 35mmHg, we are at balance!!
Comment une obstruction importante des voies urinaires, qu’elle soit aiguë ou chronique, peut-elle entraîner une insuffisance rénale, c’est-à-dire une baisse de la filtration glomérulaire?
Due to the buildup, you are increasing the pressure in the bowman capsule. In normal conditions, it should be -35mmHg which allows for filtration from afferent into the bowman space. Beacuse of the pressure build up, you wont be able to filter = insuffissance renale
baisse de la pression d’ultrafiltration qui en résulte diminue la filtration glomérulaire
Why does the bowman capsule pressure not increase as we filter out stuff from the glomerule??
Because the liquid leaves towards the rest of the kidney, resulting in a constant pressure (in healthy conditions)
- La pression hydrostatique dans le capillaire
glomérulaire
– Est diminuée par la _____________de l’artériole
préglomérulaire ou la ____________de l’artériole
_______________
vasoconstriction
vasodilatation
efferente (postglomérulaire)
Vasoconstrictor substances?
Angiotensine II, ADH, endothéline,
épinéphrine, norépinéphrine, thromboxane
Vasodilator substances?
Acétylcholine, bradykinine, dopamine,
monoxyde d’azote (NO), prostaglandines
What is the effect of Angiotensine II on the hydrostatic pressure in the glomerule? What about the oncotique pressure?
hydrostatic pressure:
Angiotensine II is a vasoconstrictor on the efferent side
this leads to an increase in hydrostatique pressure in the glomerule
this means more filtration
oncotique pressure is depentend on proteins, nothing to do with angiotestine
What is the effect of norépinéphrine on the hydrostatic pressure in the glomerule? What about Acétylcholine?
norépinéphrine is a vasoconstrictor on the afferent side
this leads to an decrease in hydrostatique pressure in the glomerule
this means less filtration
Acétylcholine is a vasodilator on the afferent side
this leads to an increase in hydrostatique pressure in the glomerule
this means more filtration
What is the rétroaction tubuloglomérulaire?
Macula Densa is a sensor of NaCl concentration
In situations where we increase hydrostatic pressure due to whatever reason, we want to eventually stop so that we do not filter too much:
Increase in hydrostatic pressure in the glomerular capillary.
Increase in glomerular filtration.
Increase in NaCl in the “macula densa”.
Increase in local production of vasoactive hormones (adenosine).
Vasoconstriction of the afferent arteriole.
Decrease in hydrostatic pressure in the glomerular capillary and decreased glomerular filtration.
What is the role of creatinine in clinical setting?
It is an endogene marker that allows to determine the taux de filtration glomerulare i.e., how much that goes in is filtered
This is becasue creatinine is 100% filtered out
What is clairance rénale?
It is the amount of a certain substance that will be filtered and not absorbed.
For example creatinine has a high renale clairance but glucose has a virtually 0 renale clearance
What does it mean when a substance has a higher Clairance rénale than filtration renale?
It means that on top of 100% of the substance being filtered and not reabsorbed, we also lost or secreted a bit from the body
