Midterm 3 Kidney Flashcards
1
Q
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
A
It is the organ of homeothermia
2
Q
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
A
Its tubular system is located in the cortex
3
Q
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
A
Its tubular system is located in the cortex
4
Q
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
A
Cells of the proximal tubule
5
Q
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
A
It displays a double capillarization
6
Q
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
A
They run alongside the deep reaching loops of Henle
7
Q
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
A
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)
8
Q
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
A
It acts through cholinergic mediation (function not clear)
9
Q
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
A
They sense the firmness of the renal capsule (stretching)
10
Q
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
A
It maintains the pressure needed for filtration by reacting to a higher pressure with constriction and to a lower pressure with dilatation
11
Q
PCT
A
Proximal convoluted tubule
12
Q
PST
A
Proximal straight tubule
13
Q
Henle loop:
DTL
A
Desc. thin limb
14
Q
Henle loop:
ATL
A
Asc. thin limb
15
Q
Henle loop:
TAL
A
Thick asc. limb
16
Q
DCT
A
Distal convoluted tubule
17
Q
CNT
A
Distal connective tubule
18
Q
CCD
A
Cortical collecting duct
19
Q
MCD
A
Medullary collecting duct
20
Q
GBM
A
Glomerular basement membrane
21
Q
What is the blood pressure in the renal arterioles?
70-250 mmHg
it changes against the midpressure
50 mmHg
120 mmHg
A
50 mmHg
22
Q
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
A
Probably in the macula densa
23
Q
RBF
A
Renal blood flow
(25%of blood flows through the kidney)
RBF = RPF/ 1 – Htc RBF = 670/ 1 – 0.44 = 1200 ml/min
24
Q
PGE
A
Prostaglandin
very strong vasodilator. Equally affects v.aff & v.eff,
so RBF increases, while GFR remains unchanged.
25
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)
26
RPF
Renal plasma flow
27
RAS
Renin Angiotensin System
28
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.
29
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.
30
What method can be used to examine the kidney's anatomical parts in an intact organism?
ultrasound
clearance test
micropuncture
isotope techniques
Ultrasound
31
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
32
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
33
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
34
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)
35
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
36
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
37
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
38
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
39
How are most materials tansported during tubular reabsorption?
paracellularly
para- and transcellularly
transcellularly
by pynocytosis
Para- and transcellularly
40
What percent of the filtration is reabsorbed in the tubular system?
30 %
99.9%
more than 90%
65 %
More than 90%
41
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
42
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
43
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
44
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
45
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
46
Which substance can be used to measure glomerular filtration rate?
inulin
para-aminohippuric acid
glucose
urea
Inulin
47
Which formula describes the clearance correctly?
C = (U x P) / V
C=U / P x V
C = (U - P) / V
C = (P x V) / U
C = U / P x V
48
What is glomerular filtration rate?
it is the amount of substance that appears in the filtrate in 1 minute
it shows what fraction of the plasma that arrives to the kidney becomes filtered
the volume of ultrafiltrate produced by the kidney per unit time
the amount of plasma flowing through the kidney per unit time
The volume of ultrafiltrate produced by the kidney per unit time
49
What substance is suitable for measuring the GFR?
urea
para-aminohippuric acid
creatine
inulin
Inulin
50
What is the filtration fraction?
it gives the fraction renal plasma flow that is filtered per unit time
it is the amount of substance that becomes filtered in 1 minute
it is the amount of substance reabsorbed per unit time
it is that fraction of the renal plasma flow that perfuses the nephrons
It gives the fraction renal plasma flow that is filtered per unit time
51
What is meant by the filtration capacity (filtered load)?
it gives the fraction of the plasma what becomes filtered
the mass of a substance that appears in the filtrate per unit
the volume of the plasma perfusing the kidney per unit time
the volume of ultrafiltrate per unit time
The mass of a substance that appears in the filtrate per unit
52
What is the average value of the GFR?
60 ml/min/100 kgbwt
75 ml/min/100 kgbwt
120 ml/min/100 kgbwt
600 ml/min/100 kgbwt
120 ml/min/100 kgbwt
53
Which formula describes the GFR?
```
GFR = (U / P) - V
GFR = (U - P) / V
GFR = (U x P) / V
GFR = (U / P) x V
```
GFR = (U / P) x V
54
By what process is inulin excreted from the kidney?
only by filtration
it filtered and then it is reabsorbed entirely from the tubules
filtration and secretion
after filtration 50% is reabsorbed in the tubules
Only by filtration
55
What is the RPF?
the amount of ultrafiltrate per unit time
the volume of plasma perfusing the kidney per unit time
it is the mass of a substance that appears in the filtrate per minute
it is the fraction of the plasma that becomes filtered
The volume of plasma perfusing the kidney per unit time
56
What is the average value of the RPF?
40 ml/min/100 kgbw
350 ml/min/100 kgbw
600 ml/min/100 kgbw
180-200 ml/min/100 kgbw
600 ml/min/100 kgbw
57
What is the formula for the RPF?
```
RPF = (U - P) / V
RPF = Pa - Pv / Pa
RPF = (U / P) x V
RPF = C / E
```
RPF = C / E
58
What substance is adequate for measuring the RPF?
para-aminohippuric acid
inulin
endogenous creatinin
urea
Para-aminohippuric acid
59
What species has a physiologically changing GFR?
cattle
dog
pig
horse
Dog
60
What is the physiological value for the filtration fraction?
45 %
15 %
20 %
8-10%
20%
61
What is true for GFR?
the mesangial cells detect the potassium concentration of the filtrate
the GFR is altered due primarily to sympathetic influence
the GFR is parallel to the mean arterial pressure
the GFR is independent of the mean arterial pressure in most species
The GFR is independent of the mean arterial pressure in most species
62
The clearance of which substances are independent of its plasma concentration?
inulin
glucose
para-aminohippuric acid
hemoglobin
Inulin
63
The transport of which substance has a Tm?
inulin
glucose
urea
water
Glucose
64
What is the tubular reabsorption maximum?
the plasma concentration value above which reabsorption is only possible through active transport
the phenomenon in which a substance is completely retained from the urine
the plasma concentration value at which all tubular cells reach the maximum of their reabsorptive capacity
the plasma concentration value at which 50 percent of the tubular cells reach the maximum of their reabsorptive capacity
The plasma concentration value at which all tubular cells reach the maximum of their reabsorptive capacity
65
How can the secretion of a substance be described in connection to its plasma concentration?
with a sigmoid curve
first it increases in a linear fashion then decreases and finally becomes parallel with the filtration
it increases in a linear fashion
for a while it increases with the plasma concentration then reaches a plateau
For a while it increases with the plasma concentration then reaches a plateau
66
Of the following statements which one is not typical of the transport taking place in the proximal tubule?
the paracellular transport is of a small scale at this section
70 percent of the filtered substance is reabsorbed
the reabsorption is obligatory in this segment
hormonal regulation is of little importance
The paracellular transport is of a small scale at this section
67
What is typical of the Na+ transport taking place in the proximal tubule?
Na+ diffuses from the interstitium to the cell
its transport depends on the Na+/K+ - ATPase pump
tubular Na+ concentration temporarily increases
Na+ moves in a passive way only
Its transport depends on the Na+/K+ - ATPase pump
68
What is typical of the H+ transport taking place in the proximal tubule?
the process does not have a significant effect on the pH of the tubular lumen
the H+ secretion is a passive process
the Na+ uptake via secondary active transport facilitates in H+ secretion
the H+ moves together with the Na + in a symport process
The Na+ uptake via secondary active transport facilitates in H+ secretion
69
What happens to the HCO3- ion in the proximal tubule?
30% of the HCO3- transforms into CO2 and water, the water is absorbed, the CO2 is excreted with the urine
in form of NaHCO3 it is passively reabsorbed
the HCO3- gets into the cell with active transport
HCO3- is reabsorbed indirectly with the mediation of CO2 formation
HCO3- is reabsorbed indirectly with the mediation of CO2 formation
70
What happens to the CO2 in the proximal tubular cell?
the carbonic anhydrase enzyme creates the HCO3-, which gets into the interstitium via a Na +/3HCO3- symport
most of the CO2 that got into the cell diffuses back into the lumen
almost all of the CO2 diffuses across the cell into the interstitium in a passive way
it gets into the interstitium via an HCO3-/Cl- antiport process
The carbonic anhydrase enzyme creates the HCO3-, which gets into the interstitium via a Na+/3HCO3-symport
71
What is typical of the Cl- transport taking place in the proximal tubule?
the Cl- absorption only takes place at high lumen pH values
it gets into the cell via Cl-/acidic anion antiport
a vast majority transforms into acid with the luminal H+ and diffuses freely into the cell
it gets into the cell through a K+/Cl- co- transport
It gets into the cell via Cl-/acidic anion antiport
72
What is typical of the water transport taking place in the proximal tubule?
water is reabsobed passively by AQP-2 channels
water transport is negligible in the proximal tubule
water moves paracellularly and transcellularly. The latter is made possible by the AQP-1 channels
paracellular transport of water is insignificant
Water moves paracellularly and transcellularly. The latter is made possible by AQP-1 channels
73
How does the transport of glucose and amino acids take place?
with Na+ antiport
no carrier proteins are needed for their transport
it takes place in only in thedescending limb of the Henle's loop with active transport
100% of the filtered amount is reabsorbed by Na+ symport
100% of the filtered amount is reabsorbed by Na+ symport
74
What is typical of the descending limb of the Henle's loop?
it is a section with relatively high permeability
there is significant active transport in both directions
it is a section with high resorptive and secretory capability
paracellular transport can be observed
It is a section with relatively high permeability
75
What is typical of the transport taking place in the ascending thick segment of the Henle's loop?
most important is the Na/K - ATPase pump function on the luminal side
the most important symport protein is the furosemid sensitive Na+/K+2Cl- transporter
30% of the filtered substance is reabsorbed here
there is negligible secretion and reabsorption here
The most important symport protein is the furosemid sensitive Na+/K+2Cl- transporter
76
What transport- processes are typical of the ascending thick segment of the Henle's loop?
the filtrate becomes highly hyperosmotic here
the electroneutral environment is not favorable to the ion transport
it is impermeable to water
Na+ reabsorption increases when furosemid is added
It is impermeable to water
77
What is typical of the transport taking place in the convoluted distal tubule?
Na+ is passively flowing into the cell in the direction of its electrical gradient
the reabsorption can be blocked by furosemid
there is a K+/Cl- co- transport on the luminal side
the Na+/Cl- symport protein facilitates the Na reabsorption
The Na+/Cl- symport protein facilitates the Na reabsorption
78
Which substance can prevent the Na +/Cl- symport protein from functioning?
tiazid
furosemid
ouabain
amilorid
Tiazid
79
Where is the hormonal regulation of little importance?
in the connecting duct
in the ascending thick limb of the Henle's loop
in the cortical segment of the collecting tubule
in the medulary portion of the collecting tubule
In the ascending thick limb of the Henle's loop
80
What is typical of the transport taking place in the cortical segment of the collecting tubule and the connecting duct?
the Na+/K+ transport on the luminal side is helped by an antiport protein
the antiport protein responsible for the ion transport can be inhibited by amilorid
the expression of the Na+ and the K+ channels is aldosterone dependent
the amilorid affects the K+ transport selectively
The expression of the Na+ and the K+ channels is aldosterone dependent
81
What is typical of water transport?
the transport of water is hormonally regulated in every portion of tubular system
the functioning of the AQP-1 channel is hormonally regulated
in the collecting tubules water moves via AQP-2 channels
ADH diminishes the number of the AQP-1 channels in the proximal tubule
In the collecting tubules water moves via AQP-2 channels
82
How does water transport take place in the collecting tubules?
it is a hormonally regulated transport
through the AQP-1 water-channels
through AQP-2 channels on the basolateral side of the cell
via paracellular, ADH regulated way
It is a hormonally regulated transport
83
Which tubular segments is permeable to urea?
proximal tubule
thin descending limb of the Henle's loop
convoluted distal tubule
cortical connecting duct
Thin descending limb of the Henle's loop
84
How do the cells protect against the hyperosmosis in the layers of the kidney?
the cell produces osmoliths, which decreases the osmolality of the liquid- layer surrounding the cell
they have a thick withstanding wall
they produce osmoliths which provide within the cell an osmolality similar to the environment
the membrane operates a special channels system which allows water to flow out actively
They produce osmoliths which provide within the cell an osmolality similar to the environment
85
How large is the osmotic gradient in the kidney of domestic animals?
600-2000 mosm/l
max. 9400 mosm/l
300-1200 mosm/l
300-2400 mosmol/l
300-1200 mosm/l
86
What is true for the countercurrent multiplier?
it is realized by the opposite flow and close anatomical vicinity of the descending and ascending tubular segments
it stabilizes low osmolarity in the medulla
it is dependent on the vasa recta system
the high osmolarity in the cortical layers is ensured by the presence of urea
It is realized by the opposite flow and close anatomical vicinity of the descending and ascending tubular segments
87
What is true for the countercurrent exchanger?
its major driving force is the sodium/ potassium/ 2 chlorides symporter
the arrangement of the vasa recta system allows the nutrient supply of the deep medullary layers without destroying the hyperosmolarity
it is based on the fact that the vasa recta run perpendicular to the loop of Henle
it ensures that the osmotic equivalents can be reabsorbed from the deep medullary interstitium
The arrangement of the vasa recta system allows the nutrient supply of the deep medullary layers without destroying the hyperosmolarity
88
What happens in the ascending thin limb of the loop of Henle?
the osmolality of luminal fluid increases
luminal fluid gets isoosmotic
NaCl is taken up from the interstitium
the tubular fluid loses osmotic equivalents
The tubular fluid loses osmotic equivalents
89
What happens in the ascending thick limb of the loop of Henle?
the luminal fluid gets isoosmotic
water diffuses out passively into the interstitium
NaCl diffuses into the interstitium passively
the tubular fluid is hypoosmotic
The tubular fluid is hypoosmotic
90
What happens in the collecting ducts?
in presence of ADH water diffuses toward the interstitium
in absence of ADH water diffuses toward the interstitium
in presence of ADH water is transported toward the interstitium in active manner
water transport depends on aldosterone in this segment
In presence of ADH water diffuses toward the interstitium
91
What is the freewater clearance?
it is the ratio of the minute diuresis and the osmotic clearance
it tells how much free water is given to the isoosmotic urine or taken back from it by the kidney
it tells how much water is extracted from the body by the kidney per minute
It gives how much water osmotically bound water passes through the kidney per unit time
It tells how much free water is given to the isoosmotic urine or taken back from it by the kidney
92
What is the osmotic plateau?
it gives the value of the highest osmotic
concentration in the kidney interstitium
it gives the degree of urine concentration in the kidney at a given time
it shows the maximum concentrating ability of the kidney
it shows the minimum volume of the water conserved
It shows the maximum concentrating ability of the kidney
93
What is the effect of the angiotensin-II on the kidney function?
it has only indirect effect on the kidney
it reduces the water uptake
it inhibits the ADH production
it indirectly increases salt retention
It indirectly increases salt retention
94
What is the primary stimulus for the aldosterone release?
increased plasma K+ concentration
increased plasma Na+ concentration
angiotensin-II
increased blood pressure
Increased plasma K+ concentration
95
Which segment is the main target of the aldosterone action?
the proximal tubule
the connecting duct and the collecting duct's cortical segment
the proximal convoluted tubule
the ascending limb of loop of Henle
The connecting duct and the collecting duct's cortical segment
96
How does the aldosterone exert its effect in kidney?
sodium potassium pump is inhibited
K+ channel proteins are inhibited
sodium potassium pump protein, Na+ channel and K+ channel proteins are increasingly expressed
Na+ channel and K+ channel proteins get inhibited
Sodium potassium pump protein, Na+ channel and K+ channel proteins are increasingly expressed
97
What is the major effect of the ADH?
the kidney rises the Na retention
inhibits the the water- retention
increases the Na reabsorption
increases the water reabsorption
Increases water reabsorption
98
What stimulates ADH secretion the most?
hyperosmosis of the plasma
increasing of blood pressure
signaling of volume receptors
increased secretion of the atrial natriuretic peptide
Hyperosmosis of the plasma
99
What is the Verney- mechanism?
Injecting hypoosmotic fluid decreases the urine production significantly
injecting hyperosmotic fluid decreases the urine production promptly
for increasing blood pressure urine production decreases
due to strong pain ADH secretion is inhibited so the urine production decreases
Injecting hyperosmotic fluid decreases the urine production promptly
100
What is the primary stimulus for the atrial natriuretic peptide?
if the Na+ concentration decreasing in the tubules
hypovolemia
dilatation of muscle
elements of the atria
high blood pressure
Dilatation of muscle elements of the atria
101
What is the basic role of the atrial natriuretic peptide?
it increases the aldosterone secretion
it increases ADH and renin secretion
it decreases the GFR
it increases the Na+ excretion, decreases the water retention
It increases the Na+ excretion, decreases the water retention
102
Which of the following hormones exerts an action on the kidney?
parathormone
d-hormone
erytropoetin
triiodidetironine
Parathormone
103
Which of the following hormones is produced in kidney?
parathormone
triiodidetironin
calcitonin
glicocorticoids
Triiodidetironin
104
Which hormone is responsible for keeping the plasma Na+ concentration at a constant level?
aldosterone
angiotenzin-II
ADH
ANP
ADH
105
What proccesses take place in the case of hyperosmosis?
increased ADH and aldosteron cause increased freewater clearance
increasing in aldosterone level causes Na+ and water loss
Na+ is reabsorbed
increased ADH causes water retention
Increased ADH causes water retention
106
What proccesses take place in the case of hypoosmosis?
first hypervolemic isoosmosis is restored
free water clearance
decreases
aldosterone level decreases
increasing Na+ excretion
First hypervolemic isoosmosis is restored
107
What proccesses take place in the case of hypovolemia?
angiotensin-II decreases
RAS gets activated
K+ retention increases
aldosteron level decreases
RAS gets activated
108
What proccesses take place in the case of hypervolemia?
ADH activation
Na+ and water loss due to RAS activation
RAS inhibition
aldosterone stimulation
RAS inhibition
109
How does the passing of the urine toward the bladder happen at normal urine production rate?
the way of flow is determined by the sympathetic tone of the ureter
due to parasympathetic stimulation
continuously
in small portion following each other
In small portion following each other
110
What inhibits the urine backflow from the bladder to the kidney?
the ureter connects to the bladder at an angle that automatically closes the pathway of urine
there is a sphintcher consisting of striated muscles in the ureter
the pressure conditions in the pelvis of the kidney
the gravitation
The ureter connects to the bladder at an angle that automatically closes the pathway of urine
111
What does the plasticity of bladder wall mean?
the wall of the bladder consists of special skeletal muscle fibres and elastic fibers
the bladder reacts to tension with relaxation
activity of intramural mechanoreceptors in the bladder increases linearly with wall tension
collagenous fibres in the bladder wall resists tension
The bladder reacts to tension with relaxation
112
Where is the regulatory center of urination?
in the thalamus
in the medulla oblongata
in the pons
in the lumbar portion of the spinal cord
In the pons
113
How is the bladder regulated in the filling phase?
due to sympathetic activity all the skeletal sphincters are contracted
activity of somatic motor system acts on the musculature of the bladder relaxing it
the musculature of the bladder is relaxed due to intense parasympathetic activity, the musculature of the urethra contracts due to sympathetic effect
sympathetic basal tone relaxes the muscles of the bladder and it inhibits the parasympathetic activity presynaptically
Sympathetic basal tone relaxes the muscles of the bladder and it inhibits the parasympathetic activity presynaptically
114
How is the bladder regulated in the phase of urination?
the wall of the bladder contracts and the sphincters dilate due to parasympathetic activity but the sympathetic and somatic activation is inhibited
the wall of the bladder contracts and the sphincters dilate due to sympathetic activation
activity of parasympathetic lumbar center is increased by the medullary center which makes the wall of the bladder contract and the sphincters relax
increased sympathetic activity inducing urination may be affected by cortical information
The wall of the bladder contracts and the sphincters dilate due to parasympathetic activity but the sympathetic and somatic activation is inhibited
