Lecture 11/13: Renal Physiology Flashcards
Final
Basic Roles of the Kidney: Describe the Kidney’s role in: BP regulation
Kidney is the long term manager of BP
if you have HTN, the kidney is suppose to fix it.
If you have chronic HTN –> something wrong with your kindeys
Basic Roles of the Kidney: Describe the Kidney’s role in: pH regulation
Kidneys produce more or less bicarb which helps balance out protons, and decide how much is reabsorbed.
-Also get rid of excess protons in urine
this helps with acid/base balance
What is the short term regulator of pH? How does this process work?
The respiratory system
-blows off CO2 to decrease protons in blood temporarily –> cant get rid of protons, kidney has to.
Basic Roles of the Kidney: Describe the Kidney’s role in: Red blood cells
Hct sensors in deep inner medulla of the kidney detect if O2 levels are low –> triggers Epoetin release (Epo) –> increase bone marrow –> increase RBC
This increase in RBC ultimately allows more oxygen to flow through the VR in the deep inner medulla
Basic Roles of the Kidney: Describe the Kidney’s role in: electrolyte regulation
Kidneys are the primary long term regulator in filtering ions bc almost everything gets reabsorbed that we eat.
Basic Roles of the Kidney: Describe the Kidney’s role in: Vitamin D
Kidney choices how much Ca++ to reabsorb–> Vitamin D is activated at the kidney
Activated vitamin D promotes Ca++ reabsorption
Basic Roles of the Kidney: Describe the Kidney’s role in: Serum glucose
It figures out how much glucose needs to be reabsorbed
If elevated a little = all reabsorbed
Elevated alot = max reabsorbed & the rest excreted
this is a safety valve bc if we just keep reabsorbing all the glucose then serum glucose would just stay high
Basic Roles of the Kidney: Describe the Kidney’s role in: Drug clearance
The kidney will filter and secrete drugs to excrete them out of the body
Basic Roles of the Kidney: Describe the Kidney’s role in: Metabolic waste
Rids of nitrogen waste products; urea
Basic Roles of the Kidney: Describe the Kidney’s role in: Osmolarity
Able to get rid of salt while hanging on to water (ADH)
Ex) hypernatremia
What are all the roles of the kidney?
- LT BP regulator
- LT PH regulator
- LT RBC regulator
- LT electrolyte regulator
- LT vitamin D regulator
- LT serum glucose regulator
- Drug clearance
- LT metabolic waste disposal
- osmolarity regulator
These things are dependent on a normal GFR
Hence why auto regulation is important
What is the order of blood flow through the renal artery and out the renal vein?
Renal artery –> Segmental arteries–> Interlobar arteries –> arcuate arteries –> interlobular arteries –>
AA –> GC –> EA –> PT cap–>
Interlobular veins –> arcuate veins –> interlobar veins –> segmental veins –> renal vein
The ______ is the function unit of the kidney
Nephron
How many nephrons are in each kidney? How many total?
1 million in each kidney
2 million total
______% of your nephrons are located in the cortex
90-95%
Where is the PT cap located? VR?
PT cap: Outer medulla/cortex
VR: deep inner medulla
____% of nephrons located in the deep inner medulla
5-10%
What is the role of the VR?
-Help concentrate the renal ISF
-Preserves osmotic gradient by minizing washout
How many descending VR do we have? Ascending? What is the purpose of this?
Descending: 1
Ascending: 2
We have MORE ascending VR to decrease the velocity of blood going up to maintain normal levels of solute in the deep inner medulla
Preventing wash out
What were to happen if the velocity of the VR were high?
The solutes in the renal ISF would be diluted!!!!
Wash out <– know this term
This creates a problem bc this messes with the gradient for reabsorbing and secreting solutes
When would it be beneficial to increase velocity of the VR to wash out the solutes in the renal ISF?
A condition where the renal ISF has a hyperosmolarity:
AKI/CKD?
If BP is decreased, which part of the kidney is most effected? why?
Deep inner medulla
Only 5-10% of capillaries are in the deep inner medulla, therefore only 5-10% of oxygen carrying blood gets to that area. Making this area very sensitive to small amount of decreased perfusion.
This can cause ischemia in the area very easy
What area of the kidney is most likely to become ischemic? Why?
Deep inner medulla
Only 5-10% of capillaries
The mesenteric artery sits _______ the renal artery & vein. It also supplies blood to the _______
on top of
intestines
The kidneys are located _________ the diaphragm
under
The adrenal gland is ______ the kidney
on top of