Renal Physiology 2 Flashcards
___________: only a fraction of the plasma presented to the glomeruli is filtered.
Filtration Fraction: only a fraction of the plasma presented to the glomeruli is filtered.
________ of plasma is filtered.
20-30% of plasma is filtered.
Filtration rate is measured in units of _______.
Filtration rate is measured in units of mL/min.
Secretion, Reabsorption and Excretion are measured in units of _________.
Secretion, Reabsorption and Excretion are measured in units of mg/min.
Excretion (E) = _______________
Excretion (E) = Filtration (F) + Secretion (S) - Reabsorption (R)
___________: maximum rate at which nephron epithelium can remove substances from plasma and secrete them into filtrate
Transport Maximum: maximum rate at which nephron epithelium can remove substances from plasma and secrete them into filtrate
Secretion transport is dependent on
Secretion transport is dependent on the number/density of membrane transporters that allow for secretion or reabsorption
When transport maximum is reached, substances that should be secreted _____________.
When transport maximum is reached, substances that should be secreted accumulate in plasma.
When transport maximum is reached, substances that should be reabsorbed __________.
When transport maximum is reached, substances that should be reabsorbed may be lost in urine.
“Splay” in graphs of [Glucose] reflects what
Heterogenicity of nephrons
Glucose in the urine can be due to:
Hemorrhage
Increased [Glucose} in plasma
Proximal tubule damage
Explain how Fight or Flight response increases plasma glucose
SNS stimulation releases epinephrine that increases glycogenolysis at the liver.
Why is the Fight or Flight response important in some species and not others in regards to [Glucose]
In some species the [Glucose] in plasma caused by the Fight or Flight response exceeds transport maximum
In what species is the Fight or Flight Response important to be aware of in regards to [Glucose]
Bovine
_______ is secreted when there is increased [Glucose] in plasma.
Insulin is secreted when there is increased [Glucose] in plasma.
[Glucose] in plasma and Filtration of Glucose is a __________ relationship.
[Glucose] in plasma and Filtration of Glucose is a linear relationship.
Normal [Glucose] in plasma for dog
70-100 mg/dL
Glucose Transport Maximum of dog
180-200 mg/dL
Decreased transport maximum means what in regards to the concentration of a substance in plasma.
More of the substance is excreted in urine when it is increased in plasma.
The _________ is the major portion of the nephron responsible for reabsorption and secretion.
The proximal tubule is the major portion of the nephron responsible for reabsorption and secretion.
The _______ does not modify osmolarity.
The Proximal Tubule does not modify osmolarity.
__________ of water is reabsorbed at the proximal tubule.
50-80% of water is reabsorbed at the proximal tubule.
_________ work at the proximal tubule to increase reabsorption of water.
NE, E, AGII work at the proximal tubule to increase reabsorption of water.
Increased reabsorption at the proximal tubule can be due to
Decreased blood pressure
Increased osmolarity
_______ of water is reabsorbed at the dLoH
20% of water is reabsorbed at the dLoH
At the ______ there is more water reabsorption than osmolyte.
At the dLoH there is more water reabsorption than osmolyte.
The ________ is considered a passive structure.
The dLoH is considered a passive structure.
Filtrate at the dLoH is _____osmotic.
Filtrate at the dLoH is hyperosmotic.
Urea from the MCD is secreted at the ________.
Urea from the MCD is secreted at the dLoH.
The _______ puts solute into the interstitium.
The aLoH puts solute into the interstitium.
The ______ has no aquaporins.
The aLoH has no aquaporins.
_______ at the aLoH increase reabsorption of water by the dLoH
NE and E at the aLoH increase reabsorption of water by the dLoH
__________ increases the reabsorption of solute at the aLoH
AcH and Aldosterone increases the reabsorption of solute at the aLoH
_________ at the MCD increases the number of aquaporins and urea transporters
ADH at the MCD increases the number of aquaporins and urea transporters
__________ at the MCD decreases Na+ reabsorption.
ANP at the MCD decreases Na+ reabsorption.
__________ at the MCD increases Na+ reabsorption.
Aldosterone at the MCD increases Na+ reabsorption.
Osmolytes become non freely filterable when
Osmolytes become non freely filterable when they are bound by plasma protein
Secretion of organic molecules occurs only in the ___________.
Secretion of organic molecules occurs only in the proximal tubule.
__________________________
Exception: Urea is secreated in the dLoH
Reabsorption of organic molecules occurs only in the ____________.
Reabsorption of organic molecules occurs only in the proximal tubule.
_______________________
Exception: Urea at the MCD
Urea (increases/decreases) along the nephron.
Urea (increases/decreases) along the nephron.
At the dLoH [Urea] (increases/decreases)
At the dLoH [Urea] (increases/decreases)
________________
To allow for diffusion into the filtrate
After the aLoH filtrate is ______osmotic
After the aLoH filtrate is hyposmotic
All medullary interstitium is ______osmotic.
All medullary interstitium is hyperosmotic.
Fractional Excretion = _____________
Fractional Excretion =
Clearance of X (mL/min) / GFR (mL/min)
UrineX:UrineCreatinine
Test comparing the ratios of substances in urine to known normals
Elevated UrineProtein:UrineCreatinine can be caused by
Tubular Disease
Glomeruplopathies
Lower Urinary Tract Disease
UrineCortisol:UrineCreatinine is used as a diagnostic tool for
Cushings Disease
Osmolar Clearance = __________.
Osmolar Clearance = Vu x Uosm / Posm.
Free Water Clearance = ______________
Free Water Clearance = Vu - Osmolar Clearance
Uosm _______ Posm:
Free water clearance = 0
No net gain or loss of plasma water
Isosmotic urine
Uosm = Posm
Uosm _______ Posm:
Free water clearance +
Net loss of plasma water
Hyposmotic urine
Uosm < Posm
Uosm _______ Posm:
Free water clearance -
Net gain of plasma water
Hyperosmotic urine
Uosm > Posm
As blood pressure decreases, the concentration of osmolytes in the urine __________.
As blood pressure decreases, the concentration of osmolytes in the urine increases
___________ urine = neither excretion nor reabsorption of solute free water and urine flow equals urine
Isosmotic urine = neither excretion nor reabsorption of solute free water and urine flow equals urine
__________ urine is divided into 2 virtual volumes; once contains solute and is isosmotic to plasma with urine flow rate equal to osmolar clearance and the second is solute free.
Hyposmotic urine is divided into 2 virtual volumes; once contains solute and is isosmotic to plasma with urine flow rate equal to osmolar clearance and the second is solute free.
__________ urine represents the volume of solute free water that would have to be added to urine to make it isosmotic to plasma, solute free water reabsorbed by the kidneys.
Hyperosmotic urine represents the volume of solute free water that would have to be added to urine to make it isosmotic to plasma, solute free water reabsorbed by the kidneys.
_________: quantifies the actual voluem of solute fre water that is being conserved by the animal over time.
Free water clearance : quantifies the actual voluem of solute fre water that is being conserved by the animal over time.
__________: ratio of the density of a volume of solution to the density of an identical volume of water.
Specific Gravity (USG): ratio of the density of a volume of solution to the density of an identical volume of water.
Free water has a USG of _______.
Free water has a USG of 1.000.
True/False: USG is a precise measure of osmolality
False
USG between ________ is the same osmolality as plasma.
USG between 1.018 - 1.020 is the same osmolality as plasma.
__________: urine excreted has an osmolality/SG essentially identical to plasma
Isosthenuria: urine excreted has an osmolality/SG essentially identical to plasma
________: urine excreted is dilute
Hyposthenuria : urine excreted is dilute
_________: urine excreted is concentrated
Hypersthenuria: urine excreted is concentrated
Water Deprivation Test
Used to test renal function. USG is measured as water is deprived over a set amount of time. In normal animal, expect to see and increase in USG as time continues.
__________: accumulation of non protein nitrogen molecules.
Azotemia: accumulation of non protein nitrogen molecules.
_______: accumulation of waste products such that toxic effects manifest.
Uremia : accumulation of waste products such that toxic effects manifest.
_________ Azotemia is caused by derangements in before the kidney.
Pre-Renal Azotemia is caused by derangements in before the kidney.
________ Azotemia is a result of kidney dysfunction.
Renal Azotemia is a result of kidney dysfunction.
_______ Azotemia is caused by derangement after the kidney
Post-Renal Azotemia is caused by derangement after the kidney
Osmolality increases in the _______
Osmolality increases in the medulla
________________
LoH and Collecting duct
2/3 loss of nephrons causes
2/3 loss of nephrons causes decreased concentrating ability
3/4 loss of nephrons causes
3/4 loss of nephrons causes kidney failure
Hyperkalemia can be caused by
Increased intake of K+ in diet
Tissue damage
Urinary blockage
Most common cause of hyperkalemia is __________.
Most common cause of hyperkalemia is urinary blockage.
_________ holds excess K+ until kidney can excrete it.
Skeletal muscle holds excess K+ until kidney can excrete it.
2 important non-protein nitrogen (NPN) molecules
Urea and Creatinine
Increased [PO42-] = _______ GFR
Increased [PO42-] = decreased GFR
___________ is important in PO42- homeostasis; decreases PO42- reabsorption.
PTH is important in PO42- homeostasis; decreases PO42- reabsorption.
___________ is an important site for reabsorption.
Proximal Tubule is an important site for reabsorption.
Reabsorption at the ________ is isosmotic.
Reabsorption at the proximal tubule is isosmotic.
Major extracellular electrolyte/osmolyte of the proximal tubule is _________.
Major extracellular electrolyte/osmolyte of the proximal tubule is Na+.
Mechanisms of Reabsorption include:
Transporters
Solvent Drag
Diffusion
Movement of molecules at the proximal tubule are associated with the movement of ______.
Movement of molecules at the proximal tubule are associated with the movement of Na+
Na+ gradient is established by the _________.
Na+ gradient is established by the Na+ - K+ ATPase.
Proteins are _____________ by proximal tubule cells.
Proteins are endocytosed and hydrolyzed by proximal tubule cells.
[Urea] _________ in the filtrate as it courses through the proximal tubule.
[Urea] increases in the filtrate as it courses through the proximal tubule.
Secretion at the proximal tubule requires_________.
Secretion at the proximal tubule requires membrane bound proteins.
_________ of total remains of Na+, water and osmoles after reabsorption at the proximal tubule.
1/3 of total remains of Na+, water and osmoles after reabsorption at the proximal tubule.
_______ of wanted electrolytes are reabsorbed at the proximal tubule.
2/3 of wanted electrolytes are reabsorbed at the proximal tubule.
CO2 + H2O ⇔ H2CO3 is catalyzed by what enzyme.
Carbonic Anhydrase
“Leakiness” of tight junctions _________ along the length of the nephron.
“Leakiness” of tight junctions decreases along the length of the nephron.
Reabsorptive force attributable to ____________ pressure.
Reabsorptive force attributable to plasma colloid oncotic pressure.
____________: direct relationship betwen volume of fluid filtered at the glomerulus and volume of fluid reabsorbed at the proximal tubule.
Glomertubular Balance: direct relationship betwen volume of fluid filtered at the glomerulus and volume of fluid reabsorbed at the proximal tubule.
_______ is the most important extracellular anion in the proximal tubule.
Cl- is the most important extracellular anion in the proximal tubule.
Reabsorption of _________ occures only in the first half of the proximal tubule.
Reabsorption of organic molecules occures only in the first half of the proximal tubule.
Reabsorption of __________ occures the entire length of the nephron.
Reabsorption of electrolytes occures the entire length of the nephron.
True/False: At the proximal tubule the Na+-Bicarb symport is important in maintaining acid base.
False, there is no such thing as a Na+-Bicarb symport
Bicarb pumped into the plasma makes plasma _______ and the filtrate __________.
Bicarb pumped into the plasma makes plasma alkaline and the filtrate acidic.
Na+-K+ ATPase is stimulated by
Norepinephrine
Epinephrine
Angiotension II
It is more common for an animal to become more (acidic/alkaline).
It is more common for an animal to become more (acidic/alkaline).
True/False: Bicarb is freely filterable
True
Reabsorption at the LoH is not ______osmotic.
Reabsorption at the LoH is not isososmotic.
Water is reabsorbed ________ in the dLoH.
Water is reabsorbed passively in the dLoH.
Solute is reabsorbed by _________ in the aLoH
Solute is reabsorbed by active transport in the aLoH
Due to H2O reabsorption in the dLoH filtrate becomes ________osmotic.
Due to H2O reabsorption in the dLoH filtrate becomes hyperosmotic.
Due to solute reabsorption in the aLoH filtrate becomes _______osmotic.
Due to solute reabsorption in the aLoH filtrate becomes hyposmotic.
_________: protein secreted by the LoH to decrease the likelihood of bacterial attachment to urinary epithelium
Uromodulin: protein secreted by the LoH to decrease the likelihood of bacterial attachment to urinary epithelium
__________ is the most abundent protein found in urine.
Uromodulin is the most abundent protein found in urine.
________ takes solute out of the medullary interstitium all the time.
Vasa Recta takes solute out of the medullary interstitium all the time.
Filtrate should be _____osmotic and interstitium should be _____osmotic.
Filtrate should be hyposmotic and interstitium should be hyperosmotic.
Transport of urea into and out of the medullary interstitium is dependent on __________.
Transport of urea into and out of the medullary interstitium is dependent on urea transporters.
The aLoH is net reabsorptive of _____.
The aLoH is net reabsorptive of K+.
_______________: medullary interstitium is all hyperosmotic, however it gets increasingly more hyperosmotic as it gets deeper into the medulla.
Counter-Current Mechanism: medullary interstitium is all hyperosmotic, however it gets increasingly more hyperosmotic as it gets deeper into the medulla.
________: a drug used to block 2Cl- - Na+K+ symports; overdose can lead to dehydration.
Lasix: a drug used to block 2Cl- - Na+K+ symports; overdose can lead to dehydration.
____________ increases urea permeability in the collecting duct by increasing the number/density of urea transporters.
ADH increases urea permeability in the collecting duct by increasing the number/density of urea transporters.
________ symport found in the aLoH is electroneutral.
2Cl- - Na+K+ symport found in the aLoH is electroneutral.
_______ stimulates the addition of aquaporins in the MCD.
ADH stimulates the addition of aquaporins in the MCD.
__________ shut down urea transporters in the MCD.
Cortisol shut down urea transporters in the MCD.
__________ increase activity of Na+-K+ ATPase in the DCT, CCD, MCD.
Aldosterone increase activity of Na+-K+ ATPase in the DCT, CCD, MCD.
________ decreases Na+ and H2O reabsorption at the MCD.
ANP decreases Na+ and H2O reabsorption at the MCD.
____________
Na+ - K+ ATPase
Na+
Na+ - Glucose/AA/PO4-
Na+ - Cl- Symport
Na+ - H+ Antiport
Proximal Tubule
Na+ - K+ ATPase
Na+
Na+ - Glucose/AA/PO4-
Na+ - Cl- Symport
Na+ - H+ Antiport
_______________
Aquaporins
Urea Transporters
dLoH and MCD
Aquaporins
Urea Transporters
____________
Na+ - K+ ATPase
2Cl- -Na+K+ Symport
aLoH
Na+ - K+ ATPase
2Cl- -Na+K+ Symport
___________
Aquaporins
H+
H+ - K+ Antiport
HCO3- - Cl- Antiport
DCT/ CCD
Aquaporins
H+
H+ - K+ Antiport
HCO3- - Cl- Antiport
[Glucose] _____ at the PCT
[Glucose] decreases at the PCT
[Na+]/[Cl-] _______ at the PCT.
[Na+]/[Cl-] decreases at the PCT.
[Na+]/[Cl-] _______ at the dLoH.
[Na+]/[Cl-] remains constant at the dLoH.
[Na+]/[Cl-] _______ at the aLoH.
[Na+]/[Cl-] decreases at the aLoH.
[Na+]/[Cl-] _______ at the DT/CD.
[Na+]/[Cl-] decreases at the DT/CD.
[H2O] ________ from PCT to CD
[H2O] decreases from PCT to CD
[Urea] ______ at the PCT.
[Urea] decreases at the PCT.
[Urea] ______ at the dLoH.
[Urea] increases at the dLoH.
[Urea] ______ at the aLoH.
[Urea] remains constant at the aLoH.
[Urea] ______ from the DT to CD.
[Urea] decreases from the DT to CD.
[CREA] _______ at the PCT.
[CREA] increases at the PCT.
[CREA] _______ from dLoH to CD.
[CREA] remains constant from dLoH to CD.
A deficiency in _________ results in loss of solute and large volumes of water in dilute urine leading to the disease state of _________.
A deficiency in ADH results in loss of solute and large volumes of water in dilute urine leading to the disease state of Diabetes Insipidus.
Diabetes Insipidus can be a result of
Dysfunction of hypothalamus or neurohypophysis
or
Deficient/ dysfunctional ADH receptrors in the kidney
_________ Diabetes Insipidus is due to a dysfunction of the hypothalmus or neurohypophysis
Central / Primary Diabetes Insipidus is due to a dysfunction of the hypothalmus or neurohypophysis
________ Diabetes Insipidus is caused by deficient or dysfunctional ADH receptors in the kidney.
Nephrogenic Diabetes Insipidus is caused by deficient or dysfunctional ADH receptors in the kidney.
__________ polydipsia occurs when the animals drinks too much.
Primary polydipsia occurs when the animals drinks too much.
________ polydipsia is due to a problem in the kidney.
Secondary polydipsia is due to a problem in the kidney.
The ALoH is constantly putting solute into the interstititium because
The ALoH is constantly putting solute into the interstititium because the vasa recta is constantly taking it out.
____________: Condition in which Na+ and Cl- are not constantly resupplied to the interstitium leading to a persistant slight loss of osmolyte to vasa recta.
Medullary Washout: Condition in which Na+ and Cl- are not constantly resupplied to the interstitium leading to a persistant slight loss of osmolyte to vasa recta.
Medullary Washout occurs due to:
ALoH not putting solute into the intersitium (Lack of hormone vs receptor)
Liver Disease (decreased Urea)
Hyperadrenocorticism is also called ________.
Hyperadrenocorticism is also called Cushings Disease
Hypoadrenocorticism is also called ________.
Hypoadrenocorticism is also called Addisons Disease.
Hyperadrenocorticism is due to an increase in ____________.
Hyperadrenocorticism is due to an increase in cortisol.
Hypoadrenocorticism is due to a decrease in _________.
Hypoadrenocorticism is due to a decrease in Aldosterone.
Diseases typically associated with Nephrogenic Diabetes Insipidus
Hypercalcemia
Hypokalemia
Glucosuria