MT #4 Kidney Physiology Flashcards
Which of the following statements is not true for the function of the kidney?
a. it is the organ of homeothermia
b. it maintains acid/base balance
c. it contributes to homeostasis
d. conserves water, electrolites, glucose and aminoacids
a. it is the organ of homeothermia
What is true for the cortical nephron?
a. its descending segments approach the papilla
b. its tubular system is located in the cortex
c. its special region is the juxtaglomerular apparatus
d. its tubular system is located in the inner medulla
b. its tubular system is located in the cortex
Which of the following statements is not true for the juxtamedullary nephron?
a. its special region is the juxtaglomerular apparatus
b. its tubular system is located in the inner medulla
c. its tubular system is located in the cortex
d. its descending segments approach the papilla
c. its tubular system is located in the cortex
Which of the following histological formations is not a part of the juxtaglomerular apparatus?
a. juxtaglomerular cells
b. macula densa cells
c. mesangial cells
d. cells of the proximal tubule
d. cells of the proximal tubule
What is true for the blood supply of the kidney?
a. the glomerular capillary continues in venules
b. the vas afferens is not a part of the nephron
c. the vas efferens continues in the
peritubular venous capillary system
d. it displays a double capillarization
d. it displays a double capillarization
What is characteristic of the system of vasa recta?
a. it surrounds the collecting tubules
b. they run alongside the deep reaching loops of Henle
c. they run perpendicularly to the proximal tubules
d. their primary function is the nutrient supply to the glomerulus
b. they run alongside the deep reaching loops of Henle
What is true for the sympathetic innervation of the kidney?
a. It is poor
b. It increased sympathetic stimualtion and causes the GFR to increase
c. most sympathetic fibres get to the afferent arterioles
d. at rest considerable sympathetic discharge can be detected
c. most sympathetic fibres get to the afferent arterioles
What is true for the parasympathetic innervation of the kidney?
a. they mostly get to the afferent arterioles
b. they detect the firmness of the renal capsule
c. the kidney is very rich in parasympathetic nerves
d. it acts through cholinergic mediation
d. it acts through cholinergic mediation
What is the role of the pain sensing fibres in the renal capsule?
a. they sense the firmness of the renal capsule
b. they react to increased renal blood flow
c. its importance is negligible
d. if activated they indirectly increase the GFR
a. they sense the firmness of the renal capsule
What does the renal autoregulation ensure?
a. a constant 80 mmHg pressure in the renal arteries
b. that the mean arterial pressure can be followed without delay in the vas afferent
c. it ensures constant blood pressure values mainly via the sympathetic nervous system
d. it maintains the pressure needed for filtration by reacting to a higher pressure with constriction and to a lower pressure with dilatation
d. it maintains the pressure needed for filtration by reacting to a higher pressure with constriction and to a lower pressure with dilatation
What is the blood pressure in the renal arterioles?
a. 70-250 mmHg
b. it changes against the midpressure
c. 50 mmHg
d. 120 mmHg
c. 50 mmHg
Where are the vasoregulative factors contributing to the renal autoregulation produced?
a. in the adrenal glands
b. in the juxtaglomerular cells
c. in the mesangial cells
d. probably in the macula densa
d. probably in the macula densa
Which of the following statements is not true for the PGE synthesized in the kidney?
a. it has an effect only on the afferent arteriole
b. it increases the RBF
c. it has a vasodilatator effect
d. it has no effect on the GFR
a. it has an effect only on the afferent arteriole
What is the role of the kallikrein-kinin system in the renal autoregulation?
a. the kinins induce strong vasoconstriction
b. bradykinin induces local vasodilatation
c. it gets activated with falling arterial midpressure
d. one of its components, the PGE, compensates the effect of the angiotensin-II
b. bradykinin induces local vasodilatation
What method can be used to examine the renal osmotic gradient?
a. clearance test
b. isotope measures
c. micropuncture
d. ultrasound
c. micropuncture
What method can be used to follow the renal function in an intact organism?
a. no methods are available
b. micropuncture
c. ultrasound
d. isotope techniques
d. isotope techniques
What method can be used to examine the kidney’s anatomical parts in an intact organism?
a. ultrasound
b. clearance test
c. micropuncture
d. isotope techniques
a. ultrasound
What method can be used to examine the renal blood flow?
a. collecting urine
b. clearance test
c. ultrasound
d. only a direct surgical operation is possible
b. clearance test
What is the reason for the 100 times larger filtration coefficient in the renal glomerulus compared to any other parts of the microcirculation?
a. there is a higher effective filtration pressure
the portal circulation of the kidney
b. the special permeability of the basal membrane
c. the increase of the colloid osmotic
d. pressure because of the protein retention
c. the increase of the colloid osmotic
Which of the following factors does not influence the rate of ultrafiltration in the renal?
a. effective filtration pressure
b. the size of the filtrating area
c. the quality of the barrier
d. the value of the arterial midpressure
d. the value of the arterial midpressure
Which formula describes the renal effective filtration pressure?
a. EFP = glomerular pressure - (capsular pressure + glomerular colloid osmotic pressure)
b. EFP = (glomerular pressure + capsular pressure) - glomerular colloid osmotic pressure
c. EFP = (glomerular pressure - glomerular colloid osmotic pressure) + capsular pressure
d. EFP = glomerular pressure - glomerular colloid osmotic pressure
a. EFP = glomerular pressure - (capsular pressure + glomerular colloid osmotic pressure)
What describes the glomerular colloid osmotic pressure within the glomerulus?
a. towards the vas efferent the pressure falls from 36 mmHg to 28 mmHg
b. towards the vas efferent the pressure rises from 28 mmHg to 36 mmHg
c. at the beginning of the vas afferent the pressure is 36 mmHg
d. it is a constant value, 36 mmHg
b. towards the vas efferent the pressure rises from 28 mmHg to 36 mmHg
What is the value of the effective filtration pressure in the vas efferent?
a. it is lower than the pressure in the vas afferent but it is never equal to 0
b. 12 mmHg
c. 4 mmHg
d. 36 mmHg
c. 4 mmHg
How much is the total ultrafiltration per day?
a. 60 litre / 100 kgbwt
b. 28-36 litre / 100 kgbwt
c. 100-120 litre / 100 kgbwt
d. 180-200 litre /100 kgbwt
d. 180-200 litre /100 kgbwt
Which factor is the most important driving force in the tubular reabsorption?
a. intravasal oncotic pressure
b. hydrostatic pressure
c. arterial midpressure
d. pulse pressure in the a. renalis
a. intravasal oncotic pressure
How are most materials tansported during tubular reabsorption?
a. paracellularly
b. para- and transcellularly
c. transcellularly
d. by pynocytosis
b. para- and transcellularly
What percent of the filtration is reabsorped in the tubular system?
a. 30%
b. 99.9%
c. more than 90%
d. 65%
c. more than 90%
What is characteristic of the tubular secretion?
a. it is exclusively a primary active transport
b. it is a passive process
c. substances get to the peritubular capillary from the tubular lumen
d. substances get to the tubular lumen from the peritubular capillary
d. substances get to the tubular lumen from the peritubular capillary
What is the average volume of urine per minute in animals?
a. 2-3 ml/min/100 kgbwt
b. 0.1 litre/day/ kgbwt
c. 10-15 ml/min/100 kgbwt
d. 0.2-0.4 ml/min/100 kgbwt
a. 2-3 ml/min/100 kgbwt
What is true for extraction?
a. substances get to the tubular lumen from the peritubular capillary
b. renal ability of removing substances from the plasma
c. its value is 0, if the kidney totally extracts the given substance
d. the process goes only against the concentracion gradient
b. renal ability of removing substances from the plasma
Which equation describes the extraction correctly?
a. E = (Pv - Pa) / Pv
b. E = (Pa + Pv) x Pa
c. E = (Pa - Pv) / Pa
d. E = (Pa-Pv) x Pa
c. E = (Pa - Pv) / Pa
What is true for clearance?
a. it is the measure of filtration
b. its measurement is only possible by surgical intervention
c. it describes the mass of material fitlered per unit time
d. it gives the amount of plasma that is entirely purified by the kidney from a given substance per unit time
d. it gives the amount of plasma that is entirely purified by the kidney from a given substance per unit time
Which substance can be used to measure glomerular filtration rate?
a. inulin
b. para-aminohippuric acid
c. glucose
d. urea
a. inulin
Which formula describes the clearance correctly?
a. C = (U x P) / V
b. C = U / P x V
c. C = (U - P) / V
d. C = (P x V) / U
b. C = U / P x V
What is glomerular filtration rate?
a. it is the amount of substance that appeares in the filtrate in 1 minute
b. it shows what fraction of the plasma that arrives to the kidney becomes filtered
c. the volume of ultrafiltrate produced by the kidney per unit time
d. the amount of plasma flowing through the kidney per unit time
c. the volume of ultrafiltrate produced by the kidney per unit time
What substance is suitable for measuring the GFR?
a. urea
b. para-aminohippuric acid
c. creatine
d. inulin
d. inulin
What is the filtration fraction?
a. It gives the fraction renal plasma flow that is filtered per unit time
b. it is the amount of substance that becomes filtered in 1 minute
c. it is the6 amount of substance reabsorbed per unit time
d. it is that fraction of the renal plasma flow that perfuses the nephrons
a. It gives the fraction renal plasma flow that is filtered per unit time
What is meant by the filtration capacity (filtered load)?
a. it gives the fraction of the plasma what becomes filtered
b. the mass of a substance that appeares in the filtrate per unit
c. the volume of the plasma perfusing the kidney per unit time
d. the volume of ultrafiltrate per unit time
b. the mass of a substance that appeares in the filtrate per unit
What is the average value of the GFR?
a. 60 ml/min/100 kgbwt
b. 75 ml/min/100 kgbwt
c. 120 ml/min/100 kgbwt
d. 600 ml/min/100 kgbwt
c. 120 ml/min/100 kgbwt
Which formula describes the GFR?
a. GFR = (U / P) - V
b. GFR = (U - P) / V
c. GFR = (U x P) / V
d. GFR = (U / P) x V
d. GFR = (U / P) x V