Podcast
Questions and Answers
What percentage of cardiac output do the kidneys normally receive in mammals?
What percentage of cardiac output do the kidneys normally receive in mammals?
- 25% (correct)
- 50%
- 10%
- 75%
The glomerulus allows high-molecular-weight proteins to pass into the glomerular filtrate.
The glomerulus allows high-molecular-weight proteins to pass into the glomerular filtrate.
False (B)
What is the primary function of the nephron?
What is the primary function of the nephron?
To filter blood and regulate substances like water, electrolytes, and waste.
The fluid produced by the glomerulus is known as _____ filtrate.
The fluid produced by the glomerulus is known as _____ filtrate.
Match the following kidney functions with their descriptions:
Match the following kidney functions with their descriptions:
What is the glomerular filtration rate (GFR) used to measure?
What is the glomerular filtration rate (GFR) used to measure?
Nephrons serve as the functional unit of the kidney.
Nephrons serve as the functional unit of the kidney.
Name the structure where blood is filtered in the nephron.
Name the structure where blood is filtered in the nephron.
What is the approximate daily production of glomerular filtrate for an average-size beagle weighing 10 kg?
What is the approximate daily production of glomerular filtrate for an average-size beagle weighing 10 kg?
The glomerular capillary wall consists of four layers.
The glomerular capillary wall consists of four layers.
What is the primary function of the juxtaglomerular apparatus?
What is the primary function of the juxtaglomerular apparatus?
The ________ is a layer of intricate, interlocking cells in the glomerulus.
The ________ is a layer of intricate, interlocking cells in the glomerulus.
Match the nephron segments with their primary functions:
Match the nephron segments with their primary functions:
What structure encases the glomerular tuft?
What structure encases the glomerular tuft?
Endothelial fenestrae allow for filtration of plasma proteins.
Endothelial fenestrae allow for filtration of plasma proteins.
Name the two types of nephrons found in avian kidneys.
Name the two types of nephrons found in avian kidneys.
The comprehensive barrier separating the blood and capsule is made up of the capillary endothelium, basement membrane, and ________.
The comprehensive barrier separating the blood and capsule is made up of the capillary endothelium, basement membrane, and ________.
What is the primary role of renal arterial blood in relation to the afferent arteriole?
What is the primary role of renal arterial blood in relation to the afferent arteriole?
Hydrostatic pressure in the glomerular capillaries favors filtration.
Hydrostatic pressure in the glomerular capillaries favors filtration.
How does the structure of the glomerular capillaries influence the filtration process?
How does the structure of the glomerular capillaries influence the filtration process?
The components of the glomerular basement membrane include various types of ________.
The components of the glomerular basement membrane include various types of ________.
Match the following terms with their descriptions:
Match the following terms with their descriptions:
What is the main force favoring filtration in the glomerulus?
What is the main force favoring filtration in the glomerulus?
Angiotensin II increases renal blood flow.
Angiotensin II increases renal blood flow.
What does the myogenic reflex do in renal physiology?
What does the myogenic reflex do in renal physiology?
In the kidney, _____ is suppressed by increased extracellular volume and increased renal perfusion pressure.
In the kidney, _____ is suppressed by increased extracellular volume and increased renal perfusion pressure.
Which of the following mechanisms is NOT a part of the autoregulation of glomerular filtration rate?
Which of the following mechanisms is NOT a part of the autoregulation of glomerular filtration rate?
Negative charges repel negatively charged plasma proteins across the filtration barrier.
Negative charges repel negatively charged plasma proteins across the filtration barrier.
What effect does angiotensin II have on sodium uptake?
What effect does angiotensin II have on sodium uptake?
The net filtration rate can be influenced by the _____ and _____ of a substance.
The net filtration rate can be influenced by the _____ and _____ of a substance.
Match the following pressures with their effects:
Match the following pressures with their effects:
What happens to the glomerular filtration rate if the afferent arterioles constrict?
What happens to the glomerular filtration rate if the afferent arterioles constrict?
The shape of a molecule affects its permeability across the glomerular filtration barrier.
The shape of a molecule affects its permeability across the glomerular filtration barrier.
What role do chemical mediators like nitric oxide play in autonomic regulation of glomerular blood flow?
What role do chemical mediators like nitric oxide play in autonomic regulation of glomerular blood flow?
The _____ system is an important regulator of GFR and renal blood flow, mediated through hormones.
The _____ system is an important regulator of GFR and renal blood flow, mediated through hormones.
Which layer of the glomerular basement membrane is relatively dark due to its resistance to electron passage?
Which layer of the glomerular basement membrane is relatively dark due to its resistance to electron passage?
The main driving force for filtration in the glomerulus is the oncotic pressure in Bowman’s space.
The main driving force for filtration in the glomerulus is the oncotic pressure in Bowman’s space.
What is the primary function of the glomerular filtration barrier?
What is the primary function of the glomerular filtration barrier?
In general, substances with a molecular radius of _____ nm or more are not filtered.
In general, substances with a molecular radius of _____ nm or more are not filtered.
Match the following components of the glomerulus with their roles:
Match the following components of the glomerulus with their roles:
Which equation represents the relationship of net ultrafiltration pressure at any point along the glomerular capillary?
Which equation represents the relationship of net ultrafiltration pressure at any point along the glomerular capillary?
The ultrafiltration coefficient is affected by the structural characteristics of the glomerular capillary wall.
The ultrafiltration coefficient is affected by the structural characteristics of the glomerular capillary wall.
What happens to the plasma oncotic pressure as blood travels through the glomerular capillaries?
What happens to the plasma oncotic pressure as blood travels through the glomerular capillaries?
The filtration barrier's permselectivity ensures that normally, proteins of the size of _____ are retained in the bloodstream.
The filtration barrier's permselectivity ensures that normally, proteins of the size of _____ are retained in the bloodstream.
Match components involved in glomerular filtration with their characteristics:
Match components involved in glomerular filtration with their characteristics:
What causes the decrease in hydrostatic pressure in the capillary along the filtration process?
What causes the decrease in hydrostatic pressure in the capillary along the filtration process?
Bowman's space is where the glomerular filtrate is formed and collected.
Bowman's space is where the glomerular filtrate is formed and collected.
What happens to filtration in the distal portions of the glomerular capillaries during increased blood flow?
What happens to filtration in the distal portions of the glomerular capillaries during increased blood flow?
The mathematical representation of GFR is GFR = Kf × _____ .
The mathematical representation of GFR is GFR = Kf × _____ .
What type of microscopy shows the three main layers of the glomerular capillary wall?
What type of microscopy shows the three main layers of the glomerular capillary wall?
What is the primary function of renin in the renin-angiotensin system?
What is the primary function of renin in the renin-angiotensin system?
Angiotensin-converting enzyme (ACE) is primarily found in the liver.
Angiotensin-converting enzyme (ACE) is primarily found in the liver.
What substance's release is increased by angiotensin II that affects renal function?
What substance's release is increased by angiotensin II that affects renal function?
The consequence of increased tubule fluid flow at the macula densa is increased [NaCl] that initiates ______.
The consequence of increased tubule fluid flow at the macula densa is increased [NaCl] that initiates ______.
Match the following components of the nephron with their functions:
Match the following components of the nephron with their functions:
Which hormone is responsible for vasoconstriction and can increase blood pressure?
Which hormone is responsible for vasoconstriction and can increase blood pressure?
The intrarenal renin-angiotensin system operates entirely independently of the systemic renin-angiotensin system.
The intrarenal renin-angiotensin system operates entirely independently of the systemic renin-angiotensin system.
What does an increase in glomerular filtration rate (GFR) indicate?
What does an increase in glomerular filtration rate (GFR) indicate?
A decrease in ______ removes NaCl from the tubule fluid due to high tubule fluid flow rate.
A decrease in ______ removes NaCl from the tubule fluid due to high tubule fluid flow rate.
What role does adenosine play in the kidney?
What role does adenosine play in the kidney?
Alpha-adrenergic stimulation can cause renal vasodilation.
Alpha-adrenergic stimulation can cause renal vasodilation.
Name one systemic factor affecting renal perfusion.
Name one systemic factor affecting renal perfusion.
The contraction of mesangial cells reduces the area available for ______.
The contraction of mesangial cells reduces the area available for ______.
Which enzyme converts angiotensinogen to angiotensin I?
Which enzyme converts angiotensinogen to angiotensin I?
What factor can contribute to changes in GFR?
What factor can contribute to changes in GFR?
Creatinine clearance can be used for determining GFR in birds.
Creatinine clearance can be used for determining GFR in birds.
What hormone contributes to the regulation of blood volume?
What hormone contributes to the regulation of blood volume?
A small increase in serum creatinine corresponds to a _____ reduction in GFR.
A small increase in serum creatinine corresponds to a _____ reduction in GFR.
Match the markers with their characteristics:
Match the markers with their characteristics:
What is a possible indicator of kidney dysfunction?
What is a possible indicator of kidney dysfunction?
An abnormally low muscle mass can cause an overestimation of renal clearance.
An abnormally low muscle mass can cause an overestimation of renal clearance.
What should be assessed to determine GFR accurately?
What should be assessed to determine GFR accurately?
Cystatin-C is not significantly altered by relative _____ mass.
Cystatin-C is not significantly altered by relative _____ mass.
What is the primary method of estimating GFR in a clinical setting?
What is the primary method of estimating GFR in a clinical setting?
Inulin is both reabsorbed and secreted by renal tubule cells.
Inulin is both reabsorbed and secreted by renal tubule cells.
What does an elevated creatinine level typically indicate?
What does an elevated creatinine level typically indicate?
In clinical correlation for chronic renal failure, the serum creatinine level was recorded as _____ mg/dL.
In clinical correlation for chronic renal failure, the serum creatinine level was recorded as _____ mg/dL.
Match the symptoms to chronic renal failure:
Match the symptoms to chronic renal failure:
What happens to renal blood flow and GFR after a single high-protein meal?
What happens to renal blood flow and GFR after a single high-protein meal?
Chronic high dietary protein intake leads to sustained increases in renal blood flow and GFR.
Chronic high dietary protein intake leads to sustained increases in renal blood flow and GFR.
What regulatory mechanism in birds causes a decrease in GFR during dehydration?
What regulatory mechanism in birds causes a decrease in GFR during dehydration?
The equation for calculating clearance is C = ___ / P, where C is the clearance, U is urine concentration, and P is plasma concentration.
The equation for calculating clearance is C = ___ / P, where C is the clearance, U is urine concentration, and P is plasma concentration.
What factor primarily reduces GFR in birds during dehydration?
What factor primarily reduces GFR in birds during dehydration?
The macula densa in avian kidneys is fully developed and regulates GFR effectively.
The macula densa in avian kidneys is fully developed and regulates GFR effectively.
What causes the vasoconstriction of the afferent arterioles in birds?
What causes the vasoconstriction of the afferent arterioles in birds?
Increased NaCl delivery to the distal nephron stimulates production of ___________ agents by macula densa cells.
Increased NaCl delivery to the distal nephron stimulates production of ___________ agents by macula densa cells.
Which of the following are potent vasodilators produced in the kidney?
Which of the following are potent vasodilators produced in the kidney?
NSAIDs can lead to increased GFR in renal failure patients.
NSAIDs can lead to increased GFR in renal failure patients.
What is the role of nitric oxide in the kidney?
What is the role of nitric oxide in the kidney?
The specific role of the connecting tubule-glomerular feedback system is presently __________.
The specific role of the connecting tubule-glomerular feedback system is presently __________.
Match the following substances with their effects on renal blood flow.
Match the following substances with their effects on renal blood flow.
Which of the following substances is mainly responsible for renal vasoconstriction?
Which of the following substances is mainly responsible for renal vasoconstriction?
The relationship between angiotensin II and macula densa COX-2 expression is always inhibitory.
The relationship between angiotensin II and macula densa COX-2 expression is always inhibitory.
What is the primary treatment to correct electrolyte and acid-base disturbances in the cat?
What is the primary treatment to correct electrolyte and acid-base disturbances in the cat?
A diet high in total protein is recommended for managing kidney disease in cats.
A diet high in total protein is recommended for managing kidney disease in cats.
What condition is indicated by the presence of 3+ protein in the urinalysis?
What condition is indicated by the presence of 3+ protein in the urinalysis?
The presence of _______ in the urine is an indicator of renal injury.
The presence of _______ in the urine is an indicator of renal injury.
What is the preferred treatment for anemia caused by chronic renal failure in cats?
What is the preferred treatment for anemia caused by chronic renal failure in cats?
Increased permeability of peripheral capillaries allows for fluid retention in the body's tissues.
Increased permeability of peripheral capillaries allows for fluid retention in the body's tissues.
What is an effective method for estimating glomerular filtration rate (GFR)?
What is an effective method for estimating glomerular filtration rate (GFR)?
The major force favoring filtration across the glomerular capillary wall is _______.
The major force favoring filtration across the glomerular capillary wall is _______.
Which of the following factors does NOT contribute to the production of peripheral edema?
Which of the following factors does NOT contribute to the production of peripheral edema?
Acute glomerulonephritis only occurs in the presence of renal failure.
Acute glomerulonephritis only occurs in the presence of renal failure.
What is the main component being addressed in the treatment of acute glomerulonephritis?
What is the main component being addressed in the treatment of acute glomerulonephritis?
Increased blood pressure and serum creatinine levels are monitored to assess _______.
Increased blood pressure and serum creatinine levels are monitored to assess _______.
What is a possible cause of acute glomerulonephritis?
What is a possible cause of acute glomerulonephritis?
What role do podocytes play in the function of the glomerulus?
What role do podocytes play in the function of the glomerulus?
Mesangial cells play a role in increasing glomerular surface area for filtration.
Mesangial cells play a role in increasing glomerular surface area for filtration.
What is the function of the negatively charged foot processes of podocytes?
What is the function of the negatively charged foot processes of podocytes?
The mesh formed by type 4 collagen contributes to the size selectivity of the ________ capillary wall.
The mesh formed by type 4 collagen contributes to the size selectivity of the ________ capillary wall.
Match the following cell types with their primary functions in the glomerulus:
Match the following cell types with their primary functions in the glomerulus:
What is the primary component that determines the charge selectivity of the glomerular basement membrane?
What is the primary component that determines the charge selectivity of the glomerular basement membrane?
Glomerular filtration occurs at a pressure of approximately 120 mmHg.
Glomerular filtration occurs at a pressure of approximately 120 mmHg.
Blood exits the glomerulus through the ________ arteriole.
Blood exits the glomerulus through the ________ arteriole.
Match the following components of the filtration barrier to their descriptions:
Match the following components of the filtration barrier to their descriptions:
Where does the majority of renal blood flow go after passing through the efferent arteriole?
Where does the majority of renal blood flow go after passing through the efferent arteriole?
The filtration barrier of the glomerulus is impermeable to water.
The filtration barrier of the glomerulus is impermeable to water.
What pressure is crucial for tubular reabsorption of fluids?
What pressure is crucial for tubular reabsorption of fluids?
Flashcards
Kidney's role in homeostasis
Kidney's role in homeostasis
The kidneys maintain a stable internal environment (homeostasis) by regulating water, electrolytes, and acid-base balance. They filter blood, reabsorb needed substances, and excrete metabolic waste products.
Cardiac output for kidneys
Cardiac output for kidneys
Approximately 25% of the heart's output goes to the kidneys in mammals.
Glomerular filtration
Glomerular filtration
The process where blood is filtered by the glomerulus, producing glomerular filtrate. Cellular components and large proteins stay in the blood.
Glomerular filtrate
Glomerular filtrate
Signup and view all the flashcards
Glomerular filtration rate (GFR)
Glomerular filtration rate (GFR)
Signup and view all the flashcards
Nephron
Nephron
Signup and view all the flashcards
Renal tubule segments
Renal tubule segments
Signup and view all the flashcards
Collecting duct system
Collecting duct system
Signup and view all the flashcards
Beagle GFR
Beagle GFR
Signup and view all the flashcards
Glomerular tuft
Glomerular tuft
Signup and view all the flashcards
Afferent arteriole
Afferent arteriole
Signup and view all the flashcards
Efferent arteriole
Efferent arteriole
Signup and view all the flashcards
Bowman's capsule
Bowman's capsule
Signup and view all the flashcards
Bowman's space
Bowman's space
Signup and view all the flashcards
Glomerular capillary wall
Glomerular capillary wall
Signup and view all the flashcards
Capillary endothelium
Capillary endothelium
Signup and view all the flashcards
Endothelial fenestrae
Endothelial fenestrae
Signup and view all the flashcards
Basement membrane
Basement membrane
Signup and view all the flashcards
Visceral Epithelium
Visceral Epithelium
Signup and view all the flashcards
Podocytes
Podocytes
Signup and view all the flashcards
Slit diaphragm
Slit diaphragm
Signup and view all the flashcards
Hydrostatic Pressure (Pgc)
Hydrostatic Pressure (Pgc)
Signup and view all the flashcards
Hydrostatic Pressure of Bowman's Space (Pbs)
Hydrostatic Pressure of Bowman's Space (Pbs)
Signup and view all the flashcards
Oncotic Pressure (πgc)
Oncotic Pressure (πgc)
Signup and view all the flashcards
Myogenic Reflex
Myogenic Reflex
Signup and view all the flashcards
Tubuloglomerular Feedback
Tubuloglomerular Feedback
Signup and view all the flashcards
Renin-Angiotensin-Aldosterone System (RAAS)
Renin-Angiotensin-Aldosterone System (RAAS)
Signup and view all the flashcards
Angiotensin II
Angiotensin II
Signup and view all the flashcards
Filtration Barrier
Filtration Barrier
Signup and view all the flashcards
Filtration
Filtration
Signup and view all the flashcards
Extracellular Volume
Extracellular Volume
Signup and view all the flashcards
Renal Perfusion Pressure
Renal Perfusion Pressure
Signup and view all the flashcards
Glomerular Basement Membrane (GBM)
Glomerular Basement Membrane (GBM)
Signup and view all the flashcards
Lamina Densa
Lamina Densa
Signup and view all the flashcards
Net Ultrafiltration Pressure (Puf)
Net Ultrafiltration Pressure (Puf)
Signup and view all the flashcards
Capillary Hydrostatic Pressure (Pgc)
Capillary Hydrostatic Pressure (Pgc)
Signup and view all the flashcards
Capillary Oncotic Pressure (πgc)
Capillary Oncotic Pressure (πgc)
Signup and view all the flashcards
Filtration Barrier Permselectivity
Filtration Barrier Permselectivity
Signup and view all the flashcards
Ultrafiltration Coefficient (Kf)
Ultrafiltration Coefficient (Kf)
Signup and view all the flashcards
Glomerular Capillaries
Glomerular Capillaries
Signup and view all the flashcards
Visceral Epithelial Cells
Visceral Epithelial Cells
Signup and view all the flashcards
Renin's function
Renin's function
Signup and view all the flashcards
Angiotensinogen source
Angiotensinogen source
Signup and view all the flashcards
Angiotensin I conversion
Angiotensin I conversion
Signup and view all the flashcards
ACE location
ACE location
Signup and view all the flashcards
Intrarenal RAS
Intrarenal RAS
Signup and view all the flashcards
Tubuloglomerular feedback (TGF)
Tubuloglomerular feedback (TGF)
Signup and view all the flashcards
Macula densa location
Macula densa location
Signup and view all the flashcards
Juxtaglomerular apparatus components
Juxtaglomerular apparatus components
Signup and view all the flashcards
TGF response to increased glomerular filtration
TGF response to increased glomerular filtration
Signup and view all the flashcards
Increased tubule fluid flow
Increased tubule fluid flow
Signup and view all the flashcards
Adenosine role in TGF
Adenosine role in TGF
Signup and view all the flashcards
GFR
GFR
Signup and view all the flashcards
Angiotensin II effect
Angiotensin II effect
Signup and view all the flashcards
Aldosterone effect
Aldosterone effect
Signup and view all the flashcards
Atrial natriuretic peptides
Atrial natriuretic peptides
Signup and view all the flashcards
TGF mechanism
TGF mechanism
Signup and view all the flashcards
What is GFR?
What is GFR?
Signup and view all the flashcards
What happens to GFR with protein intake?
What happens to GFR with protein intake?
Signup and view all the flashcards
How does bird GFR differ?
How does bird GFR differ?
Signup and view all the flashcards
What is Clearance?
What is Clearance?
Signup and view all the flashcards
How is Clearance calculated?
How is Clearance calculated?
Signup and view all the flashcards
What is Tubuloglomerular Feedback?
What is Tubuloglomerular Feedback?
Signup and view all the flashcards
What is the effect of increased NaCl delivery?
What is the effect of increased NaCl delivery?
Signup and view all the flashcards
What does macula densa activation do?
What does macula densa activation do?
Signup and view all the flashcards
What is the Connecting Tubule-Glomerular Feedback?
What is the Connecting Tubule-Glomerular Feedback?
Signup and view all the flashcards
What are Endothelium-Derived Constricting Factors?
What are Endothelium-Derived Constricting Factors?
Signup and view all the flashcards
What are Endothelium-Derived Relaxing Factors?
What are Endothelium-Derived Relaxing Factors?
Signup and view all the flashcards
What is the role of NO?
What is the role of NO?
Signup and view all the flashcards
How do NSAIDs affect GFR?
How do NSAIDs affect GFR?
Signup and view all the flashcards
How is GFR regulated?
How is GFR regulated?
Signup and view all the flashcards
Glomerulonephritis
Glomerulonephritis
Signup and view all the flashcards
Proteinuria
Proteinuria
Signup and view all the flashcards
Hypoalbuminemia
Hypoalbuminemia
Signup and view all the flashcards
Peripheral edema
Peripheral edema
Signup and view all the flashcards
Red blood cell casts
Red blood cell casts
Signup and view all the flashcards
What causes proteinuria in glomerulonephritis?
What causes proteinuria in glomerulonephritis?
Signup and view all the flashcards
How does low albumin contribute to edema?
How does low albumin contribute to edema?
Signup and view all the flashcards
How is glomerulonephritis diagnosed?
How is glomerulonephritis diagnosed?
Signup and view all the flashcards
What's the role of immunosuppressive and anti-inflammatory drugs in glomerulonephritis treatment?
What's the role of immunosuppressive and anti-inflammatory drugs in glomerulonephritis treatment?
Signup and view all the flashcards
Why are blood pressure and urine protein/creatinine ratios monitored in glomerulonephritis?
Why are blood pressure and urine protein/creatinine ratios monitored in glomerulonephritis?
Signup and view all the flashcards
What are some potential causes of acute glomerulonephritis?
What are some potential causes of acute glomerulonephritis?
Signup and view all the flashcards
What's the difference between acute and chronic glomerulonephritis?
What's the difference between acute and chronic glomerulonephritis?
Signup and view all the flashcards
How does the renin-angiotensin-aldosterone system (RAAS) contribute to edema in glomerulonephritis?
How does the renin-angiotensin-aldosterone system (RAAS) contribute to edema in glomerulonephritis?
Signup and view all the flashcards
What is the role of erythropoiesis stimulating agents (ESAs) in managing glomerulonephritis?
What is the role of erythropoiesis stimulating agents (ESAs) in managing glomerulonephritis?
Signup and view all the flashcards
What's the significance of monitoring serum creatinine in glomerulonephritis?
What's the significance of monitoring serum creatinine in glomerulonephritis?
Signup and view all the flashcards
GFR regulation
GFR regulation
Signup and view all the flashcards
Hormonal GFR control
Hormonal GFR control
Signup and view all the flashcards
GFR Units
GFR Units
Signup and view all the flashcards
Avian creatinine issue
Avian creatinine issue
Signup and view all the flashcards
Serum creatinine as indicator
Serum creatinine as indicator
Signup and view all the flashcards
Limitations of creatinine
Limitations of creatinine
Signup and view all the flashcards
Cystatin-C for GFR
Cystatin-C for GFR
Signup and view all the flashcards
Cystatin-C in dogs & cats
Cystatin-C in dogs & cats
Signup and view all the flashcards
GFR estimation equations
GFR estimation equations
Signup and view all the flashcards
GFR via Clearance
GFR via Clearance
Signup and view all the flashcards
Inulin for GFR
Inulin for GFR
Signup and view all the flashcards
Endogenous creatinine clearance
Endogenous creatinine clearance
Signup and view all the flashcards
Accuracy of creatinine clearance
Accuracy of creatinine clearance
Signup and view all the flashcards
Chronic renal failure
Chronic renal failure
Signup and view all the flashcards
Symptoms of chronic renal failure
Symptoms of chronic renal failure
Signup and view all the flashcards
What is the filtration barrier composed of?
What is the filtration barrier composed of?
Signup and view all the flashcards
What is the role of podocytes?
What is the role of podocytes?
Signup and view all the flashcards
What is the function of the glomerular basement membrane (GBM)?
What is the function of the glomerular basement membrane (GBM)?
Signup and view all the flashcards
What is the importance of high glomerular pressure?
What is the importance of high glomerular pressure?
Signup and view all the flashcards
What is the significance of low capillary pressure?
What is the significance of low capillary pressure?
Signup and view all the flashcards
What is the myogenic reflex?
What is the myogenic reflex?
Signup and view all the flashcards
How does the filtration barrier contribute to permselectivity?
How does the filtration barrier contribute to permselectivity?
Signup and view all the flashcards
Type 4 Collagen's Role
Type 4 Collagen's Role
Signup and view all the flashcards
Podocyte Foot Processes
Podocyte Foot Processes
Signup and view all the flashcards
Mesangial Cells
Mesangial Cells
Signup and view all the flashcards
Glomerular Sclerosis
Glomerular Sclerosis
Signup and view all the flashcards
Factors Affecting Filtration
Factors Affecting Filtration
Signup and view all the flashcards
Study Notes
Kidney Physiology Overview
- Kidneys receive 25% of cardiac output in mammals
- Function in several capacities: filtration, reabsorption of needed substances (water, glucose, electrolytes, proteins), and excretion of waste
- Respond to changes in water, electrolyte, and acid-base balance by altering reabsorption/secretion rates
- Produce hormones regulating blood pressure and red blood cell production
- Nephrons are the functional units, composed of glomerulus (filtration) and renal tubule (reabsorption/secretion)
- Nephrons merge into collecting ducts, which empty into renal pelvis
- Knowledge largely based on mouse, rat, and rabbit studies
Glomerular Filtration
- First step in kidney function: blood filtration by glomerulus
- Glomerulus: dense capillary network
- Retains large cellular components and proteins
- Produces glomerular filtrate (plasma-like fluid)
- Glomerular Filtration Rate (GFR): useful clinical measure, expressed in mL/min/kg
- GFR of a 10kg beagle is approximately 37mL/minute or 53.3 liters/day
- Glomerular structure facilitates efficient filtration
Structure of the Glomerulus
- Glomerular tuft composed of a network of capillaries
- Blood flows from afferent arteriole to glomerular capillaries, then to efferent arteriole
- Bowman's capsule surrounds glomerular tuft, lined with parietal epithelium; transitional to proximal tubule cells
- Bowman's space located between glomerular tuft and Bowman's capsule
- Glomerular capillary wall has three layers: endothelium, basement membrane, and visceral epithelium
Glomerular Filtration Rate Determinants
- GFR determined by net filtration pressure, filtration barrier permeability, and available surface area
- Favoring filtration: glomerular capillary hydrostatic pressure, opposing filtration: oncotic pressure in glomerular capillaries, hydrostatic pressure in Bowman's space
- Net ultrafiltration pressure (Puf) = (Pgc - πgc) - Pbs
- Glomerular capillary wall is selectively permeable:
- Molecules < 4 nm radius filter easily
- Molecules > 4 nm radius are typically retained in the capillary
- Plasma proteins remain in bloodstream due to charge and size.
Glomerular Filtration Rate Regulation
- GFR regulated by systemic and intrinsic factors
- Systemic factors: renin-angiotensin-aldosterone system (RAAS). RAAS is activated by reduced renal perfusion pressure. Renin converts angiotensinogen into angiotensin I, which further converts to angiotensin II, causing vasoconstriction.
- Intrinsic factors:
- Myogenic reflex: automatic response to changes in glomerular perfusion pressure, affects preglomerular arterioles
- Tubuloglomerular feedback (TGF): balances single nephron GFR with tubule transport capacity. Triggered by changes in sodium chloride concentration in distal nephron
Measurement of GFR
- Inulin clearance is the gold standard (freely filtered, not reabsorbed or secreted)
- Endogenous creatinine clearance is commonly used (freely filtered, but potentially secreted)
- Serum creatinine levels indicate GFR
Clinical Correlations
- Chronic renal failure: characterized by elevated serum creatinine, decreased GFR, often seen in geriatric cats
- Glomerulonephritis: characterized by proteinuria, hematuria, possible edema, often acute
- Treatment strategies for both conditions focus on supportive care, managing symptoms, and potentially addressing the underlying cause
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers key concepts of kidney physiology, including the roles of the kidneys in filtration, reabsorption, and waste excretion. It also addresses the structure and function of nephrons and the significance of glomerular filtration rate (GFR) as a clinical measure. Test your understanding of these essential processes in mammalian physiology.
