Renal Pt 1 Flashcards
What does the kidneys excrete?
How many days does it take for the excretion pump to ramp up if you ingest alot of sodium?
Excretion:
Uria
Creatinine
Metabolites of hormones
End Products of hemoglobin breakdown
2-3 days
Kidney order superficial to deep
Capsule
Cortex
Medulla
Pelvis
Kidneys get what percent of CO through blood flow?
How much blood flow per minute?
22%
1100 mL/min
(NOT THE SAME AS PLASMA/FILTRATE)
Afferent arterioles =
Efferent arterioles =
Peritubular =
Afferent arterioles = entering glomerulus
Efferent arterioles = EXITING glomerulus (goes to ascending loop)
Peritubular = around tubules
Renal arteries split into:
Interlobar
Arcuate
InterlobULar arteries
Glomerular and Peritubular capillaries have ______ duties decided by their ___________
Glomerular vs Peritubular capillaries:
They have opposite duties, which is decided by their hydrostatic pressure.
Glomerular = _______ hydrostatic pressure
If you ________ flow into Afferent glomerular capillaries, you ________ GFR.
Glomerular = high hydrostatic
If you increase flow into Afferent glomerular capillaries, you increase GFR.
_______ hydrostatic pressure is like a very full hose and the water is pushing on the walls. If the walls were permeable, then fluid would leak out, aka filtering out. The _______ is true for peritubular capillaries
High hydrostatic pressure is like a very full hose and the water is pushing on the walls. If the walls were permeable, then fluid would leak out, aka filtering out. The reverse is true for peritubular capillaries
If you increase the flow into the glomerulus via the afferent arteriole, more fluid & pressure = ________ GFR. if you constrict the efferent, aka the exit, you will ________ GFR.
If you increase the flow into the glomerulus via the afferent arteriole, more fluid & pressure = higher GFR. if you constrict the efferent, aka the exit, you will increase GFR as well.
Nephron Flow Order
Bowman’s capsule/glomerulus
Proximal tubule
Loop of Henle (thin, thin, thick)
Macula Densa
Distal Tubule
Cortical collecting tubule
Medullary collecting tubule
Collecting duct
basic functional unit of a kidney is the
Nephron
Juxtamedullary vs Cortical Nephrons
Which is outer and which is deep?
Cortical Nephrons are COMMON (outer Cortex)
Juxtamedullary (deep) have a U, because they concentrate your Urine
They also have vasa recta, which I remember because recta sounds like straight/regular/erect
Filtration: goes?
Reabsorption: comes?
Secretion: goes?
Last Step?
Filtration: out of capillaries into bowman’s
Reabsorption: back into capillaries
Secretion: out of capillaries into tubule
Excretion
Both filtration and secretion are the exact same thing essentially, just the same process at DIFFERENT locations, hence while the formula for excretion is F - R + S = E
Creatinine is _______ Filtered or Reabsorbed?
Creatinine is 100% Filtered
Electrolytes get initially _____, but then _________ partially
Electrolytes get initially filtered, but then reabsorbed partially
If they were fully one thing, then you’d always have imbalances
AA and glucose: are ________ and then _________
Organic acids/bases: rapidly _______
Main 3 end products that are excreted:
AA and glucose: are Filtered and then Reabsorbed Fully. remember together, because pissing glucose is mostly in diabetics.
Organic acids/bases: rapidly cleared (filtered and excreted)
Main 3 end products that are excreted: Urea, Uric Acid, Creatinine
This is why one of the kidney function calculations is called CrCl, or creatinine clearance.
The last thing part is rapid because if you both filter and secrete it, they both make up excretion.
High GFR = ______ removal of waste.
High GFR = faster removal of waste.
You have ____ of plasma in you.
A typical GFR is ______/day
You filter your PLASMA ______x a day
You have 3L of plasma in you.
A typical GFR is 180L/day
You filter your PLASMA 60x a day
Not the same as how much blood flows to your kidneys!
Does your filtrate contain proteins or RBCs
Your filtrate does not contain proteins or RBCs because glomerular capillaries are impermeable to protein
GFR = ____% of your renal plasma flow
GFR = 20% of your renal plasma flow
Glomerular capillary membrane = _______ charged to prevent ________ from crossing. ______ layers
Glomerular capillary membrane = negatively charged to prevent proteins from crossing. 3 layers
FIltrate does not contain _______ because glomerular capillaries are impermeable to ______
FIltrate does not contain proteins because glomerular capillaries are impermeable to protein
Endothelium = _______
Basement membrane = ______
Epithelium = ________
Endothelium = fenestrated (small holes)
Basement membrane = Big holes, meshwork of collagen
Epithelium = podocytes (long foot-like processes), slit pores through which filtrate moves
All negatively charged
Note that _______ and ______ are filtered at the same rate as water, but they are both reabsorbed. Albumin is a ______, which is filtered _______.
Note that Sodium and glucose are filtered at the same rate as water, but they are both reabsorbed. Albumin is a protein, which is filtered barely.
GFR is made up of a few pressures.
Glomerular hydrostatic pressure =____
Bowman’s Capsule Pressure = _____
Glomerular colloid osmotic Pressure = ____
Net filtration pressure = ______
Lower filtration coefficient (Kf)= ______ GFR
GFR is made up of a few pressures.
Glomerular hydrostatic pressure (60)
Bowman’s Capsule Pressure (-18)
Glomerular colloid osmotic Pressure (-32)
Net filtration pressure = 10
Lower filtration coefficient (Kf)= lower GFR
More blood flow (afferent dilation) =
Increased GFR (higher Kf)
Less blood flow (afferent constriction and/or efferent dilation) can lead to what?
Increased or decreased GFR and Kf?
kidney stones, CKD, HTN
Decreased GFR (lower Kf)
So to remember the determinants and which way they go, you have to consider what direction filtration is going.
The Glomerulus is the _____ part, so filtering is ______ the glomerulus, going into the _______ part, which is Bowman’s capsule.
So to remember the determinants and which way they go, you have to consider what direction filtration is going.
The Glomerulus is the INNER part, so filtering is LEAVING the glomerulus, going into the OUTER part, which is Bowman’s capsule.
Capillary Hydrostatic pressure pushes ______, so its part of the _______.
Bowman’s capsule Hydrostatic pressure is pushing out, but because its on the outside, its technically _______ the glomerular capillary
Hydrostatic pressure pushes OUT, so its part of the filtration.
Bowman’s capsule Hydrostatic pressure is pushing out, but because its on the outside, its technically Pushing into the Glomerular capillary
Capillary Colloid osmotic pressure just means proteins are getting _______, so pressure is going ______.
Filtration coefficient is just how much _____ do you have available for filtering. Less ______/less permeability = _______
Capillary Colloid osmotic pressure just means proteins getting sucked in, so pressure is going INSIDE capillaries.
Filtration coefficient is just how much area do you have available for filtering. Less area/less permeability = less filtering
Renal artery pressure =
Renal artery pressure = systemic arterial pressure. (BP)
Renal Artery Blood Flow Resistance is determined by 3 sets of arterioles:
Resistance is determined by 3 sets of arterioles:
InterlobULar
Afferent/Efferents
Do kidneys regulate their own renal blood flow?
________ play the biggest role in constricting renal arterioles/lowering GFR
Kidneys still regulate their own renal blood flow
Sympathetics play the biggest role in constricting renal arterioles/lowering GFR
_________ arterioles are pretty much the most important of the arterioles, so assume they play a role in ________and _____, which are the biggest parts of kidney physiology.
Afferent/Efferent arterioles are pretty much the most important of the arterioles, so assume they play a role in GFR and blood flow, which are the biggest parts of kidney physiology.
Angiotensin 2: VERY IMPORTANT
Constricts both afferent and efferents, but mainly _______. ________ GFR but _______ renal blood flow.
This is where ACE inhibitors work. They prevent AT1 conversion to AT2. Hence, ACE inhibitors ________ BP, but also _______ GFR
Angiotensin 2: VERY IMPORTANT
Constricts both afferent and efferents, but mainly efferents. Increases GFR but lower renal blood flow.
This is where ACE inhibitors work. They prevent AT1 conversion to AT2. Hence, ACE inhibitors LOWER BP, but also LOWER GFR.
ACE inhibitors are known to be kidney-protective, since increase renal blood flow = ________, and _______ GFR prevents them from working too hard
. ACE inhibitors are known to be kidney-protective, since increase renal blood flow = good perfusion, and lowering GFR prevents them from working too hard
Low renal blood flow = more time to reabsorb _________. Low renal blood flow is usually just a patient with ________.
Low renal blood flow = more time to reabsorb Na+ and water. Low renal blood flow is usually just a patient with low BP.
GFR Regulation: The Macula Densa is most receptive to ________ concentrations.
Controls _______ and _______
Affects ________ arterioles
The Macula Densa is most receptive to SODIUM CHLORIDE concentrations.
Controls renal blood flow and GFR
Affects both afferent and efferent arterioles
If Macula Densa senses _______, it will dilate the ________ arterioles and release __________.
If it senses LOW sodium, it will dilate the afferent arterioles and release renin.
Dilated Afferents = ______ GFR
_______ GFR = more _______ filtered so that you can _________ more later.
________ constricts Efferent arterioles = _______ GFR
Dilated Afferents = higher GFR
Higher GFR = more sodium filtered so that you can reabsorb more later.
Renin constricts Efferent arterioles = higher GFR
_____ doesn’t affect GFR heavily, only ________ affects GFR heavily.
SBP doesn’t affect GFR heavily, only renal blood flow affects GFR.
Urine formation: IMPORTANT: ________ is more important than _________ in terms of final excretion.
Urine Formation IMPORTANT: Reabsorption is more important than secretion in terms of final excretion.
Remember that _____ and ______ are poorly absorbed, hence why you see them in urine.
The top two electrolytes reabsorbed are _______ and ______.
Remember that urea and creatinine are poorly absorbed, hence why you see them in urine.
The top two electrolytes reabsorbed are glucose and bicarb.
Tubular Reabsorption
Transcellular = ______
Paracellular =________ This is going through __________
Once out of the lumen of the nephron and in between the capillaries and tubules, ____________ occurs.
Active transport = ______
Secondary active = ______
Transcellular = “across cell”, aka through it.
Paracellular = “next to cell”, aka between two cells. This is going through “tight junctions”
Once out of the lumen of the nephron and in between the capillaries and tubules, ultrafiltration/bulk flow occurs.
Active transport = ATP
Secondary active = glucose
Tubular Reabsorption
There’s multiple ATPase pumps, but the ________ ATPase is probably the most important.
Tubular Reabsorption
There’s multiple ATPase pumps, but the Sodium Potassium ATPase is probably the most important.
Knowing which side you’re on is very important, aka brush/luminal vs basal/basement membrane. Sodium ________ diffuses into _______. But it is ________ transported into the actual blood.
Essentially, pumping sodium into the blood means ___________ in the tubular cells. Therefore sodium passively diffuses across the _________ into the __________.
Knowing which side you’re on is very important, aka brush/luminal vs basal/basement membrane. Sodium passively diffuses into tubular cells. But it is actively transported into the actual blood.
Essentially, pumping sodium into the blood means low concentration in the tubular cells. Therefore sodium passively diffuses across the brush border into the tubular cells.
Tubular Reabsorption of Glucose:
Two glucose co-transporters: __________ and ________.
_________ does the BULK (located in the ___________)
Both of these __________ glucose
It’s technically secondary transport because _______ is the primary part. (SG = ________).
Two glucose co-transporters: SGLT2 and SGLT1.
SGLT2 does the BULK (located in the proximal convoluted tubule)
Both of these REABSORB glucose (because pissing glucose is not normal)
It’s technically secondary transport because sodium is the primary part. (SG = sodium glucose).
Counter Transport = __________
Just a way to ____________ essentially.
_______ passively diffuses from lumen into ________ because it is _______- transported from ________ to blood.
Since _______ is coming in, it can spin the door so _______ ions can leave. _______ energy required.
Counter Transport = Secondary active Transport
Just a way to save energy essentially.
Sodium passively diffuses from lumen into tubular cell because sodium is actively transported from tubule epithelial cells to blood.
Since sodium is coming in, it can spin the door so hydrogen ions can leave. No energy required.
What do the kidneys regulate?
Regulation:
Waste
BP
Acid/Base (excrete acid, regulate bicarbonate)
Electrolytes
Hormones (also excreted)
Water
Erythrocyte production (secrete erythropoietin in hypoxic situations)
What do the kidneys regulate?
Regulation:
Waste
BP
Acid/Base
Electrolytes
Hormones
Water
Secretion plays an important role in excreting ______
Secretion plays an important role in excreting K and H
Electrolytes highly reabsorbed
Na, Cl, Bicarbonate
_______ and ________ not freely filtered because they are partially bound to proteins
Calcium (50%) and fatty acids (most)
Glomerular filtrate is _________
Glomerular filtrate= filtered fluid
Kidneys have an AUTO REGULATION SYSTEM to maintain renal blood flow and GFR between _______
Auto regulation system called?
80 and 170 mmHg
Juxtaglomerular complex (Macula Densa and juxtaglomerular cells)
Angiotensin II is a powerful ________, a ______/________ formed in the _________.
Causes greater reabsorption of _________
Angiotensin II is a powerful vasoconstrictor, a circulating hormone/autacoid, and is formed in the kidneys and systemic circulation
Causes greater reabsorption of Na, K, and water
2 feedbacks components to control GFR
___________cells - group of _______ cells in the ________
__________ cells - on ______ of ___________ arterioles
Macula dense cells - group of epithelial cells in the distal tubules
Juxtaglomerular cells - on walls of afferent and efferent arterioles
