Week 18 / Renal system 2 Flashcards
What is the role of the distal convoluted tubules in the nephron?
A: The distal convoluted tubules of several nephrons empty into a single collecting duct.
Where do collecting ducts from nephrons converge?
Collecting ducts unite and converge into several hundred large papillary ducts.
Into which structures do papillary ducts drain?
Papillary ducts drain into the minor calyces, which lead to the major calyces, renal pelvis, and ureters.
Function of nephron:
What is the primary function of the renal corpuscle?
Filtration of blood plasma into the nephron.
Function of nephron:
What occurs in the renal tubule and collecting duct?
Tubular reabsorption: Substances are reabsorbed from the fluid into the blood.
Tubular secretion: Substances are secreted from the blood into the tubular fluid.
Function of nephron:
Q: What is the role of the afferent arteriole in the nephron?
A: It carries blood to the glomerulus for filtration.
Function of nephron:
Q: What is the function of the glomerular capsule (Bowman’s capsule)?
A: It collects the filtrate from the glomerulus.
Function of nephron:
Q: What is the significance of the efferent arteriole in nephron function?
A: It carries blood away from the glomerulus and leads to the peritubular capillaries.
Function of nephron:
Q: What is the role of peritubular capillaries?
A: They allow reabsorbed substances from the renal tubule to enter back into the blood.
Function of nephron:
Q: What does the fluid in the renal tubule eventually become?
A: Urine, which contains excreted substances.
Function of nephron:
Q: What happens to blood after reabsorption and secretion processes in the nephron?
A: It contains reabsorbed substances and continues through the circulatory system.
Renal Corpuscle :
Flashcard 1
Q: What two main structures make up the renal corpuscle?
A: The glomerular (Bowman’s) capsule and the glomerulus.
Renal Corpuscle :
Flashcard 2
Q: What is the function of the parietal layer of the glomerular (Bowman’s) capsule?
A: It forms the outer structural layer of the capsule.
Renal Corpuscle :
Flashcard 3
Q: What is the role of the afferent arteriole in the renal corpuscle?
A: It brings blood into the glomerulus for filtration.
Renal Corpuscle :
Flashcard 4
Q: What is the function of juxtaglomerular cells?
A: They secrete renin and help regulate blood pressure.
Renal Corpuscle :
Flashcard 5
Q: What are mesangial cells and their function?
A: They provide structural support, regulate blood flow in the glomerulus, and clear debris.
Renal Corpuscle :
Flashcard 6
Q: What is the capsular space in the renal corpuscle?
A: It is the space between the parietal and visceral layers of the Bowman’s capsule where filtrate collects.
Renal Corpuscle :
Flashcard 7
Q: What is the macula densa, and what is its role?
A: It is a group of specialized cells in the ascending limb of the nephron loop that detect sodium concentration in the filtrate and regulate glomerular filtration rate.
Renal Corpuscle :
Flashcard 8
Q: What is the function of the efferent arteriole in the renal corpuscle?
A: It carries blood away from the glomerulus after filtration.
Renal Corpuscle :
*Flashcard 9**
Q: What structure leads to the proximal convoluted tubule?
A: The capsular space funnels filtrate into the proximal convoluted tubule.
Renal Corpuscle :
Flashcard 10
Q: What is a podocyte, and where is it located?
-
A: A podocyte is a cell of the visceral layer of the glomerular capsule that wraps around glomerular capillaries.
Renal Corpuscle :
Q: What are pedicels in the renal corpuscle?
A: Pedicels are the foot-like extensions of podocytes that form filtration slits.
Renal Corpuscle :
Flashcard 12
Q: What is the role of the endothelium of the glomerulus?
A: It forms part of the filtration membrane, allowing passage of water and small solutes while blocking large molecules like proteins
Glomerular Filtration :
Flashcard 1
Q: What is the glomerular filtration process?
Flashcard 2
Q: What are the three key components of the filtration membrane?
Flashcard 3
Q: What is the role of the capillary endothelium in the filtration membrane?
Flashcard 4
Q: How does the basement membrane function in filtration?
Flashcard 5
Q: What is the significance of the foot processes of podocytes in glomerular filtration?
Flashcard 6
Q: What is a filtration slit?
Flashcard 7
Q: What is the role of the slit diaphragm in the filtration process?
Flashcard 8
Q: What happens to the filtrate once it passes through the filtration membrane?
Flashcard 9
Q: What is a fenestration (pore) in the capillary endothelium?
A: It is the process by which blood plasma is filtered through the filtration membrane in the glomerulus to form filtrate in the capsular space.
A:
1. Capillary endothelium
2. Basement membrane
3. Foot processes of podocytes
A: It contains fenestrations (pores) that allow plasma and small molecules to pass while blocking blood cells.
A: It acts as a molecular sieve, preventing large proteins from passing into the filtrate while allowing water and small solutes through.
A: They create filtration slits that allow fluid and small molecules to pass while preventing the passage of larger molecules like proteins.
A: A narrow gap between the foot processes of podocytes through which filtered fluid passes.
A: It spans the filtration slits to provide an additional barrier, allowing selective filtration of smaller molecules.
A: It enters the capsular space, becoming the fluid that moves into the renal tubule for further processing.
A: It is a small opening that permits the passage of water, ions, and small solutes but blocks blood cells.
Pressures Involved in Glomerular Filtration
Q: What is glomerular (blood) hydrostatic pressure and its typical value?
Flashcard 2
Q: What is blood colloid osmotic pressure and its typical value?
Flashcard 3
Q: What is capsular hydrostatic pressure and its typical value?
Flashcard 4
Q: How do these pressures determine the net filtration pressure (NFP)?
Flashcard 5
Q: What does a positive net filtration pressure (NFP) indicate?
A: It is the blood pressure in the glomerular capillaries, driving fluid and solutes out of the blood and into the capsular space.
Typical value: 55 mm Hg.
A: It is the osmotic pressure exerted by proteins in the blood, pulling water back into the capillaries from the filtrate.
Typical value: 30 mm Hg.
A: It is the pressure exerted by the fluid already in the capsular space, opposing filtration.
Typical value: 15 mm Hg.
Typical calculation:
NFP = 55 mm Hg – (30 mm Hg + 15 mm Hg) = 10 mm Hg.
A: It indicates that filtration is occurring, with fluid moving from the glomerulus into the capsular space
Regulation of Glomerular Filtration Rate (GFR)
Flashcard 1
Q: How do intrinsic mechanisms regulate GFR?
Flashcard 2
Q: What are the two main intrinsic mechanisms for GFR regulation?
Flashcard 3
Q: How do extrinsic mechanisms regulate GFR?
Flashcard 4
Q: What are the two main extrinsic mechanisms for GFR regulation?
Flashcard 5
Q: What is the primary goal of intrinsic GFR regulation?
Flashcard 6
Q: What is the primary goal of extrinsic GFR regulation?
A: Intrinsic mechanisms directly regulate GFR by adjusting the diameter of afferent and efferent arterioles to maintain a stable GFR despite moderate changes in blood pressure (80–180 mm Hg mean arterial pressure).
A:
1. Myogenic mechanism: Responds to changes in blood pressure by contracting or relaxing the afferent arteriole.
2. Tubuloglomerular feedback: The macula densa detects changes in NaCl levels in the filtrate and adjusts arteriole diameter accordingly.
A: Extrinsic mechanisms indirectly regulate GFR by maintaining systemic blood pressure, ensuring sufficient pressure for filtration in the kidneys.
A:
1. Sympathetic nervous system: Constricts afferent arterioles during stress or low blood pressure, reducing GFR to prioritize blood flow to vital organs.
2. Renin-angiotensin-aldosterone system (RAAS): Activates in response to low blood pressure, increasing systemic blood pressure and restoring GFR.
A: To maintain a consistent GFR and kidney function despite fluctuations in blood pressure.
A: To maintain systemic blood pressure to ensure adequate filtration pressure in the kidneys.
Hormonal Regulation of Glomerular Filtration Rate (GFR)
Flashcard 1
Q: Which two hormones contribute to the regulation of GFR?
Flashcard 2
Q: What is the effect of angiotensin II on GFR?
Flashcard 3
Q: What triggers the release of atrial natriuretic peptide (ANP)?
Flashcard 4
Q: How does ANP affect the glomerulus and GFR?
Flashcard 5
Q: What is the primary role of ANP in the regulation of GFR?
A: Angiotensin II and Atrial Natriuretic Peptide (ANP).
A: Angiotensin II is a potent vasoconstrictor of both afferent and efferent arterioles, which reduces GFR by decreasing blood flow through the glomerulus.
A: A sudden large increase in blood pressure stretches the cardiac atria, causing the release of ANP.
A: ANP causes the glomerulus to relax, increasing the surface area available for filtration, which enhances GFR.
A: To increase GFR and promote the excretion of excess fluid and sodium, helping to lower blood pressure.
Flashcard Set: Hormones and Homeostasis in Kidney Function
Flashcard 1
Q: Which five hormones regulate renal tubule function and help maintain homeostasis?
What do these hormones have an effect on to and extent?
What do they maintain?
Flashcard 2
Q: What is the role of angiotensin II in kidney function?
Flashcard 3
Q: How does antidiuretic hormone (ADH) regulate water balance?
Flashcard 4
Q: What is the function of aldosterone in the renal system?
Flashcard 5
Q: How does atrial natriuretic peptide (ANP) affect GFR and blood pressure?
Flashcard 6
Q: What role does parathyroid hormone (PTH) play in kidney function?
A:
1. Angiotensin II
2. Antidiuretic Hormone (ADH)
3. Aldosterone
4. Atrial Natriuretic Peptide (ANP)
5. Parathyroid Hormone (PTH)
the extent of Nat, CM, Cart, and water reabsorption as well as K* secretion by the renal tubules.
homeostasis of not only renal blood flow and B.P., but systemic blood flow and B.P.
A: It promotes vasoconstriction of arterioles, enhances Na+ and water reabsorption, and stimulates aldosterone release, increasing blood pressure and GFR.
A: ADH increases water reabsorption in the collecting ducts by promoting the insertion of aquaporins, reducing urine output and increasing blood volume.
A: Aldosterone enhances Na + and water reabsorption while promoting K +secretion, helping to regulate blood pressure and electrolyte balance.
A: ANP increases GFR by relaxing the glomerulus, promoting the excretion of Na + and water, which reduces blood volume and blood pressure.
A: PTH increases calcium reabsorption in the renal tubules and decreases phosphate reabsorption, helping to regulate calcium and phosphate balance in the blood.
Flashcard 1
Q: Where is antidiuretic hormone (ADH) released from, and in response to what condition?
Flashcard 2
Q: How does ADH affect water reabsorption in the kidneys?
Q: What happens to water permeability in the absence of ADH?
Q: What is facultative water reabsorption?
What role does ADH play in maintaining homeostasis?
A: ADH is released by the posterior pituitary in response to low blood flow in the hypothalamus.
A: ADH increases facultative water reabsorption by enhancing the water permeability of principal cells in the last part of the distal convoluted tubule and throughout the collecting duct.
A: The apical membranes of principal cells become almost impermeable to water, reducing water reabsorption and leading to increased urine output.
A: It is the reabsorption of water in response to the body’s hydration needs, regulated by ADH.
A: ADH helps conserve body water, maintain blood volume, and regulate blood pressure by adjusting water reabsorption in the kidneys.
Q: Where is parathyroid hormone (PTH) released from?
Q: What effect does PTH have on calcium reabsorption in the kidneys?
Flashcard 3
Q: How does PTH affect phosphate (HPO ) reabsorption in the kidneys?
Flashcard 4
Q: What is the primary role of PTH in regulating mineral balance?
Flashcard 5
Q: Why is it important for PTH to inhibit phosphate reabsorption?
A: PTH is released by the parathyroid glands.
A: PTH stimulates cells in the early distal convoluted tubule to reabsorb calcium (Ca 2+) into the blood.
A: PTH inhibits phosphate reabsorption in the proximal convoluted tubule, promoting phosphate excretion in the urine.
A: PTH helps increase blood calcium levels by promoting calcium reabsorption and phosphate excretion in the kidneys.
A: Inhibiting phosphate reabsorption helps prevent the formation of calcium phosphate crystals, maintaining the balance of calcium and phosphate in the blood.
Flashcard Set: Proximal Convoluted Tubule (PCT) Function and Transport
Flashcard 1
Q: What percentage of water is reabsorbed in the proximal convoluted tubule (PCT)?
Flashcard 2
Q: How is sodium (Na+) reabsorbed in the PCT?
Flashcard 3
Q: What percentage of potassium (K+) is reabsorbed in the PCT?
Flashcard 4
Q: How is glucose reabsorbed in the PCT?
Flashcard 5
Q: What percentage of amino acids is reabsorbed in the PCT?
Flashcard 6
Q: What is the reabsorption percentage of chloride (Cl-) in the PCT?
Flashcard 7
Q: How is bicarbonate (HCO(_3^-)) reabsorbed in the PCT?
Flashcard 8
Q: What is the reabsorption rate of urea in the PCT?
Flashcard 9
Q: How are calcium (Ca(^{2+})) and magnesium (Mg(^{2+})) reabsorbed in the PCT?
Flashcard 10
Q: What is secreted into the urine from the PCT?
Flashcard 11
Q: How does secretion of H(^+) and NH(_4^+) in the PCT vary?
Flashcard 12
Q: What is the osmolality of the tubular fluid at the end of the PCT?
A: 65% of water is reabsorbed into the blood through osmosis.
A: 65% of sodium is reabsorbed via sodium-potassium pumps, symporters, and antiporters.
A: 65% of potassium is reabsorbed through diffusion.
A: 65% of potassium is reabsorbed through diffusion.
A: 100% of glucose is reabsorbed using symporters and facilitated diffusion.
A: 100% of amino acids are reabsorbed using symporters and facilitated diffusion.
A: 50% of chloride is reabsorbed through diffusion.
A: 80-90% of bicarbonate is reabsorbed via facilitated diffusion.
A: 50% of urea is reabsorbed via diffusion.
A: Calcium and magnesium are reabsorbed at variable rates through diffusion.
A: H(^+) (protons), NH(_4^+) (ammonium), urea, and a small amount of creatinine are secreted.
A: Secretion of H(^+) and NH(_4^+) is variable and increases in acidosis via antiporters.
A: The tubular fluid remains isotonic to blood at the end of the PCT, with an osmolality of 300 mOsm/L.
Flashcard Set: Loop of Henle Function and Transport
Flashcard 1
Q: What percentage of water is reabsorbed in the descending limb of the Loop of Henle?
Flashcard 2
Q: How is sodium (Na(^+)) reabsorbed in the ascending limb of the Loop of Henle?
Flashcard 3
Q: What percentage of potassium (K(^+)) is reabsorbed in the ascending limb of the Loop of Henle?
Flashcard 4
Q: How is chloride (Cl(^-)) reabsorbed in the ascending limb of the Loop of Henle?
Flashcard 5
Q: What is the reabsorption rate of bicarbonate (HCO(_3^-)) in the Loop of Henle?
Flashcard 6
Q: How are calcium (Ca(^{2+})) and magnesium (Mg(^{2+})) reabsorbed in the Loop of Henle?
Flashcard 7
Q: What is secreted into the urine from the Loop of Henle?
Flashcard 8
Q: What is the osmolality of the tubular fluid at the end of the Loop of Henle?
A: 15% of water is reabsorbed via osmosis in the descending limb.
A: 20-30% of sodium is reabsorbed using symporters in the ascending limb.
A: 20-30% of potassium is reabsorbed through symporters in the ascending limb.
A: 35% of chloride is reabsorbed through symporters in the ascending limb.
A: 10-20% of bicarbonate is reabsorbed through facilitated diffusion.
A: Calcium and magnesium are reabsorbed at variable rates through diffusion.
A: Urea is secreted into the urine through recycling from the collecting duct.
A: The tubular fluid is hypotonic at the end of the Loop of Henle, with an osmolality of 100-150 mOsm/L.
Flashcard Set: Renal Corpuscle and Glomerular Filtration
Flashcard 1
Q: What is the typical glomerular filtration rate (GFR)?
Flashcard 2
Q: What substances are filtered in the renal corpuscle?
Flashcard 3
Q: What is the composition of the fluid at the renal corpuscle?
Flashcard 4
Q: Why are proteins not filtered in the renal corpuscle?
A: The typical GFR is 105-125 mL/min of fluid that is isotonic to blood.
A: The renal corpuscle filters water and all solutes present in blood (except proteins), including ions, glucose, amino acids, creatinine, and uric acid.
A: The fluid at the renal corpuscle is isotonic to blood, meaning it has the same concentration of solutes as plasma, excluding proteins.
A: Proteins are typically too large to pass through the filtration membrane of the glomerulus, which prevents them from being filtered into the renal tubules
Flashcard Set: Early Distal Convoluted Tubule Function and Transport
Flashcard 1
Q: What percentage of water is reabsorbed in the early distal convoluted tubule?
Flashcard 2
Q: How is sodium (Na(^+)) reabsorbed in the early distal convoluted tubule?
Flashcard 3
Q: What percentage of chloride (Cl(^-)) is reabsorbed in the early distal convoluted tubule?
Flashcard 4
Q: How is calcium (Ca(^{2+})) reabsorbed in the early distal convoluted tubule?
A: 10-15% of water is reabsorbed via osmosis in the early distal convoluted tubule.
A: 5% of sodium is reabsorbed via symporters in the early distal convoluted tubule.
A: 5% of chloride is reabsorbed via symporters in the early distal convoluted tubule.
A: Calcium reabsorption in the early distal convoluted tubule is variable and is stimulated by parathyroid hormone (PTH).
Flashcard Set: Late Distal Convoluted Tubule and Collecting Duct Function and Transport
Flashcard 1
Q: What percentage of water is reabsorbed in the late distal convoluted tubule and collecting duct?
Flashcard 2
Q: How is sodium (Na(^+)) reabsorbed in the late distal convoluted tubule and collecting duct?
Flashcard 3
Q: How is bicarbonate (HCO(_3^-)) reabsorbed in the late distal convoluted tubule and collecting duct?
Flashcard 4
Q: How is urea handled in the late distal convoluted tubule and collecting duct?
Flashcard 5
Q: What is secreted into the urine from the late distal convoluted tubule and collecting duct?
Flashcard 6
Q: What determines whether the tubular fluid leaving the collecting duct is dilute or concentrated?
A: 5-9% of water is reabsorbed, with the insertion of water channels stimulated by ADH.
A: 1-4% of sodium is reabsorbed through sodium-potassium pumps and sodium channels, stimulated by aldosterone.
A: The reabsorption of bicarbonate is variable, depending on the secretion of H(^+) (via antiporters).
A: Urea is reabsorbed in a variable amount, contributing to recycling back to the loop of Henle.
A: Potassium (K(^+)) is secreted in variable amounts to adjust for dietary intake, and H(^+) is secreted in variable amounts to maintain acid-base homeostasis.
A: The fluid is dilute when ADH levels are low and concentrated when ADH levels are high.
