Midterm 3 Kidney Flashcards
Which of the following statements is not true for the function of the kidney?
it is the organ of homeothermia
it maintains acid/base balance
it contributes to homeostasis
conserves water, electrolites, glucose and aminoacids
It is the organ of homeothermia
What is true for the cortical nephron?
its descending segments approach the papilla
its tubular system is located in the cortex
its special region is the juxtaglomerular apparatus
its tubular system is located in the inner medulla
Its tubular system is located in the cortex
Which of the following statements is not true for the juxtamedullary nephron?
its special region is the juxtaglomerular apparatus
its tubular system is located in the inner medulla
its tubular system is located in the cortex
its descending segments approach the papilla
Its tubular system is located in the cortex
Which of the following histological formations is not a part of the juxtaglomerular apparatus?
juxtaglomerular cells
macula densa cells
mesangial cells
cells of the proximal tubule
Cells of the proximal tubule
What is true for the blood supply of the kidney?
the glomerular capillary continues in venules
the vas afferens is not a part of the nephron
the vas efferens continues in the peritubular venous capillary system
it displays a double capillarization
It displays a double capillarization
What is characteristic of the system of vasa recta?
it surrounds the collecting tubules
they run alongside the deep reaching loops of Henle
they run perpendicularly to the proximal tubules
their primary function is the nutrient supply to the glomerulus
They run alongside the deep reaching loops of Henle
What is true for the sympathetic innervation of the kidney?
It is poor
It increases sympathetic stimualtion and causes the GFR to increase
most sympathetic fibres get to the afferent arterioles
at rest considerable sympathetic discharge can be detected
Most sympathetic fibres get to the afferent arterioles
(Mostly runs to the α – adrenergic receptors of v. afferent. Result of Stimulation: vasoconstriction of afferent arterioles, therefore GFR is reduced. At rest, AP firing is minimal, while during physical activity or stress AP firing is intensive)
What is true for the parasympathetic innervation of the kidney?
they mostly get to the afferent arterioles
they detect the firmness of the renal capsule
the kidney is very rich in parasympathetic nerves
it acts through cholinergic mediation
It acts through cholinergic mediation (function not clear)
What is the role of the pain sensing fibres in the renal capsule?
they sense the firmness of the renal capsule
they react to increased renal blood flow
its importance is negligible
if activated they indirectly increase the GFR
They sense the firmness of the renal capsule (stretching)
What does the renal autoregulation ensure?
a constant 80 mmHg pressure in the renal arteries
that the mean arterial pressure can be followed without delay in the vas afferent
it ensures constant blood pressure values mainly via the sympathetic nervous system
it maintains the pressure needed for filtration by reacting to a higher pressure with constriction and to a lower pressure with dilatation
It maintains the pressure needed for filtration by reacting to a higher pressure with constriction and to a lower pressure with dilatation
PCT
Proximal convoluted tubule
PST
Proximal straight tubule
Henle loop:
DTL
Desc. thin limb
Henle loop:
ATL
Asc. thin limb
Henle loop:
TAL
Thick asc. limb
DCT
Distal convoluted tubule
CNT
Distal connective tubule
CCD
Cortical collecting duct
MCD
Medullary collecting duct
GBM
Glomerular basement membrane
What is the blood pressure in the renal arterioles?
70-250 mmHg
it changes against the midpressure
50 mmHg
120 mmHg
50 mmHg
Where are the vasoregulative factors contributing to the renal autoregulation produced?
in the adrenal glands
in the juxtaglomerular cells
in the mesangial cells
probably in the macula densa
Probably in the macula densa
RBF
Renal blood flow
(25%of blood flows through the kidney)
RBF = RPF/ 1 – Htc RBF = 670/ 1 – 0.44 = 1200 ml/min
PGE
Prostaglandin
very strong vasodilator. Equally affects v.aff & v.eff,
so RBF increases, while GFR remains unchanged.
What is the role of the kallikrein-kinin system in the renal autoregulation?
the kinins induce strong vasoconstriction
bradykinin induces local vasodilatation
it gets activated with falling arterial midpressure
one of its components, the PGE, compensates the effect of the angiotensin-II
Bradykinin induces local vasodilatation
Effect: stimulates the hepatic Kininogen, resulting in Bradykinin production, which is a strong vasodilator (like the PGE)
RPF
Renal plasma flow
RAS
Renin Angiotensin System
What method can be used to examine the renal osmotic gradient?
clearance test
isotope measures
micropuncture
ultrasound
Micropuncture
By the improvement of techniques the production of such fine glass capillaries became possible, which could be introduced to the different sections of the tubules and it was possible to take samples under a microscope from the most diverse segments.
What method can be used to follow the renal function in an intact organism?
no methods are available
micropuncture
ultrasound
isotope techniques
Isotope techniques
The labelled substance (isotope) intravenously
administered to the peripheral venous system appears in the kidney, there it reaches a maximum concentration, and as time passes it eliminates with defined speed.
What method can be used to examine the kidney’s anatomical parts in an intact organism?
ultrasound
clearance test
micropuncture
isotope techniques
Ultrasound
What method can be used to examine the renal blood flow?
collecting urine
clearance test
ultrasound
only a direct surgical operation is possible
Clearance test
Clearance is a measure of the volume of plasma completely freed
of a given substance per unit time by the kidney (the usual unit is
ml/min). It is a measure of the ability of the kidney to remove a
substance from the blood plasma and to forward it to the urine (to
put it in another way: clearance
What is the reason for the 100 times larger filtration coefficient in the renal glomerulus compared to any other parts of the microcirculation?
there is a higher effective filtration pressure
the portal circulation of the kidney
the special permeability of the basal membrane
the increase of the colloid osmotic pressure because of the protein retention
The special permeability of the basal membrane
Which of the following factors does not influence the rate of ultrafiltration in the renal glomerulus?
effective filtration pressure
the size of the filtrating area
the quality of the barrier
the value of the arterial mid pressure
The value of the arterial mid pressure
Which formula describes the renal effective filtration pressure?
EFP = glomerular pressure - (capsular pressure + glomerular colloid osmotic pressure)
EFP = (glomerular pressure + capsular pressure) - glomerular colloid osmotic pressure
EFP = (glomerular pressure - glomerular colloid osmotic pressure) + capsular pressure
EFP = glomerular pressure - glomerular colloid osmotic pressure
EFP = glomerular pressure - (capsular pressure + glomerular colloid osmotic pressure)
What describes the glomerular colloid osmotic pressure within the glomerulus?
towards the vas efferent the pressure falls from 36 mmHg to 28 mmHg
towards the vas efferent the pressure rises from 28 mmHg to 36 mmHg
at the beginning of the vas afferent the pressure is 36 mmHg
it is a constant value, 36 mmHg
Towards the vas efferent the pressure falls from 36 mmHg to 28 mmHg
What is the value of the effective filtration pressure in the vas efferent?
it is lower than the pressure in the vas afferent but it is never equal to 0
12 mmHg
4 mmHg
36 mmHg
4 mmHg
How much is the total ultrafiltration per day?
60 litre / 100 kgbwt
28-36 litre / 100 kgbwt
100-120 litre / 100 kgbwt
180-200 litre /100 kgbwt
180-200 litre / 100kgbwt
Which factor is the most important driving force in the tubular reabsorption?
intravasal oncotic pressure
hydrostatic pressure
arterial midpressure
pulse pressure in the a. renalis
Intravasal oncotic pressure
How are most materials tansported during tubular reabsorption?
paracellularly
para- and transcellularly
transcellularly
by pynocytosis
Para- and transcellularly
What percent of the filtration is reabsorbed in the tubular system?
30 %
99.9%
more than 90%
65 %
More than 90%
What is characteristic of the tubular secretion?
it is exclusively a primary active transport
it is a passive process
substances get to the peritubular capillary from the tubular lumen
substances get to the tubular lumen from the peritubular capillary
Substances get to the tubular lumen from the peritubular capillary
What is the average volume of urine per minute in animals?
2-3 ml/min/100 kgbwt
0.1 litre/day/ kgbwt
10-15 ml/min/100 kgbwt
0.2-0.4 ml/min/100 kgbwt
2-3 ml/min/100 kgbwt
What is true for extraction?
substances get to the tubular lumen from the peritubular capillary
renal ability of removing substances from the plasma
its value is 0, if the kidney totally extracts the given substance
the process goes only against the concentracion gradient
Renal ability of removing substances from the plasma
Which equation describes the extraction correctly?
E = (Pv - Pa) / Pv E = (Pa + Pv) x Pa E = (Pa - Pv) / Pa E = (Pa-Pv) x Pa
E = (Pa - Pv) / Pa
What is true for clearance?
it is the measure of filtration
its measurement is only possible by surgical intervention
it describes the mass of material fitlered per unit time
it gives the amount of plasma that is entirely purified by the kidney from a given substance per unit time
It gives the amount of plasma that is entirely purified by the kidney from a given substance per unit time