Hydrostatic pressure of glomerular capsule

[gracy]

Effective filtration pressure is produced by
1-blood pressure in blood capillaries which is about 55mmHg.
2-The osmotic pressure of blood which is 30 mm Hg
3-hydrostatic pressure of glomerular capsule which is 10 mm Hg
blood pressure in blood capillaries and the osmotic pressure of blood I understand but what is hydrostatic pressure of glomerular capsule I know it is caused by filtrate that reaches into the Bowman's capsule.But how that filtrate exerts pressure?

 

[Andy Resnick]

Does this:
http://droualb.faculty.mjc.edu/Course%20Materials/Physiology%20101/Chapter%20Notes/Fall%202011/chapter_18%20Fall%202011.htm

help?

 

[gracy]

I have done 1 mistake in my 1st post.
Effective filtration pressure is produced by
1-blood pressure in blood capillaries which is about 55mmHg.
2-The osmotic pressure of blood which is 30 mm Hg
3-hydrostatic pressure of glomerular capsule which is 15 mm Hg
blood pressure in blood capillaries and the osmotic pressure of blood I understand but what is hydrostatic pressure of glomerular capsule I know it is caused by filtrate that reaches into the Bowman's capsule.But how that filtrate exerts pressure?

 

[Bystander]

But how that filtrate exerts pressure?

Andy R's link doesn't specifically delineate the extent or volume of the system handling the "filtrate" from Bowman's capsule (that I've found so far reading it), but it is pretty much closed, and that means that it's subject to pressures exerted on it by the body --- apparently most of that is just back pressure from the reabsorption of the filtrate by tissues downstream from the capsule.

The filtrate exerts pressure by resisting flow in the plumbing downstream from Bowman's capsule is about the best I can paraphrase things for you.

 

[gracy]

resisting flow

Flow of ?

 

[Bystander]

Flow of ?

Filtrate. Since it's moving into a closed system to be re-absorbed into the body, it's pretty much in its own way.

 

[gracy]

apparently most of that is just back pressure from the reabsorption of the filtrate by tissues downstream from the capsule.

Which tissue are you talking about?

Is it this one?

 

[gracy]

It is (the one I have pointed out in image above)proximal convoluted tube ,right?

 

[Bystander]

Whatever tissues are downstream. There's a section in Andy's link that starts with, "
Reabsorption
Reabsorption is the movement of filtered solutes and water from the lumen of the tubule back into the plasma.
Solute Reabsorption," and then totally loses me. I'm finding it a bit baffling that kidneys go through all the trouble of separating material/solutes from the blood stream just to mix them back into the blood stream.

 

[gracy]

Any fluid that is contained within a closed space,exerts hydrostatic pressure on the wall/boundary of that space.So the filtrate exerts pressure on the wall of bowman's capsule as well as on the capillary bed within the capsule.This pressure is called hydrostatic pressure of glomerular capsule.Right?

 

[Bystander]

As near as I can understand what is written in the link, yes.

 

[gracy]

As near as I can understand what is written in the link, yes.

If you think so,it should be correct.:)

 

[Andy Resnick]

blood pressure in blood capillaries and the osmotic pressure of blood I understand but what is hydrostatic pressure of glomerular capsule I know it is caused by filtrate that reaches into the Bowman's capsule.But how that filtrate exerts pressure?

If I understand your question, the hydrostatic pressure within Bowman's capsule is due to the nephron being 'full of fluid', just as blood hydrostatic pressure is due to the blood vessels being full of fluid- the filtrate exerts outward pressure on the walls of the nephron and Bowman's capsule.

 

[Andy Resnick]

Filtrate. Since it's moving into a closed system to be re-absorbed into the body, it's pretty much in its own way.

The nephron is not closed- it's a tube, one end of which (along with many others) opens into renal pyramids, the papillae and calyces. But it is true that 99+% of fluid that enters a nephron is transferred back into the blood.

I'm finding it a bit baffling that kidneys go through all the trouble of separating material/solutes from the blood stream just to mix them back into the blood stream.

The kidney is a regulatory organ- it regulates the amount of salt and water that is in your body. The kidney is involved with control of blood pressure and body weight (among other things). Different tubule segments of the nephron (convoluted tubule, thick ascending limb, collecting duct, etc.) have different transporters: for example, nearly all amino acids are reabsorbed within the proximal tubule, while the loop of Henle is involved with osmotic control and concentrating the urine.