Regulation of body fluid volume Flashcards
what do you look at regulating volume?
-sodium
does osmolality increase with sodium increase?
-yes
what is the ECV?
-effective circulating volume
-
what happens to the ECV when there is heart failure?
- lower ECV in the kidneys
- majority of blood stuck in ventricles
how is the ECV detected
- by the baroreceptors
- detects changes in pressure in blood vessels
what happens if there is too much fluid?
- a lot of excess fluid in blood vessels
- so blood vessels stretch
- baroreceptors notice stretch
what happens if there is not enough fluid?
- vessels not as stretched
- as not enough fluid in blood vessels
- blood vol drops
what is the blood pressure determined by?
-amount of fluid in the body
where are the two different baroreceptors found in the body?
- afferent arterioles in kidney
- arch of aorta
what is released when the blood volume drops?
-renin, released by baroreceptors
what do the chemoreceptors do?
-look at the chemical composition of filtrate.
what are the baroreceptors associated with
-PRESSURE
what happens to the vessels when there is a drop in the B.P,
-vessels aren’t as stretched
explain the process when renin is released
- renin released when BP is low
- hydrostatic pressure is high, and filtrate goes into PCT
- filter goes into pct at slower rate, therefore more time to reabsorb.
- filter hits the chemoreceptors
- chemoreceptors see that there isn’t a lot of sodium because its been reabsorbed
- sends message to baroreceptors saying theres little sodium as pct picked it all up.
- more renin released
why is it important to have sodium in the body?
as More sodium coming in, means more fluid comes in and this is needed when there is a low BP
