Physiology Osborn Renal Ps3: Glomerular Filteration And Renal Blood Flow

Front 1

6. (normal) Plasma oncotic pressure in
glomerular capillary

G S L

(normal ) Oncotic pressure of Bowman’s space

Back 1

Greater than .. Normally the oncotic pressure (protein
concentration) of bowman’s space is zero,
because normally proteins do not pass through
the filtration barrier

Front 2

7. Hydrostatic pressure at final segment of
glomerular capillary

G S L

Hydrostatic pressure at initial segment of
peritubular capillary

Back 2

Greater than…There will always be a pressure drop across the capillaries, so the pressure as the blood enters the efferent arterioles must be greater than the pressure of the blood as it leaves the efferent arteriole

Front 3

8. Oncotic pressure at the initial segment of the
glomerular capillary

G S L

Oncotic pressure at the initial segment of
peritubular capillary

Back 3

Less than.. Since water leaves the glomerular capillaries,
but proteins do not, the proteins will become
more concentrated by the time the blood exits
the glomerular capillaries. The increased
oncotic pressure of the peritubular capillaries
favors reabsorption of water and solutes into
those capillaries

Front 4

9. Hydrostatic pressure at beginning of
glomerular capillary

G S L

Hydrostatic pressure in Bowman’s space

Back 4

Greater than.. The hydrostatic pressure difference between
glomerular capillaries and Bowman’s space
favors filtration

Front 5

10. Hydrostatic pressure at the final segment of
the glomerular capillary

G S L

Oncotic pressure at the final segment of the
glomerular capillary

Back 5

Greater than.. Because the oncotic and hydrostatic pressures
in Bowman’s space are normally zero (oncotic)
or very small (hydrostatic), the forces that
determine filtration in the glomerular capillary
are primarily the capillary hydrostatic and the
capillary oncotic pressure (hydrostatic favors
filtration, and oncotic opposes it). Filtration
occurs along the entire length of the
glomerular capillary, so the hydrostatic pressure must be greater than the oncotic pressure, even at the end of the capillary

Front 6

11. The fluid in Bowman’s space contains
A. proteins in the same concentration as in the glomerular capillary plasma
B. electrolytes in the same concentration as in glomerular capillary plasma
C. only solutes that will be eliminated in the urine
D. only electrolytes, and no other solutes
E. all solutes at a higher concentration than in the glomerular capillary plasma

Back 6

B. Filtration is by bulk flow, and there is no barrier to electrolytes, water, and small solutes, including both waste products and essential nutrients. On the other hand, there is a barrier to nearly all proteins. The solutes present in the fluid of Bowman’s space will be present in the same concentration as in the plasma, since any difference in solute concentration would be quickly corrected by the free movement of water.

Front 7

12. Which of the following would initially increase the GFR:
A. lower than normal concentration of albumin in the plasma (“hypoalbunemia”)
B. significant loss of nephrons, as in renal disease
C. hemorrhage, accompanied by significant decrease in mean arterial pressure
D. increased activity in sympathetic nerves
E. vasodilation of the efferent arterioles

Back 7

A. Plasma oncotic pressure opposes filtration, so decreased plasma oncotic pressure will increase GFR.

Front 8

Significant loss of nephrons, as in renal disease does what to the GFR?

Back 8

Since GFR measures the filtration rate of the total tissue, reducing the tissue will reduce the GFR, at least initially (there is often compensation that can return the GFR back to normal)

Front 9

GFR does what?

Back 9

measures the filtration rate of the total tissue

Front 10

hemorrhage, accompanied by significant decrease in mean arterial pressure does what to the GFR?

Back 10

tends to decrease GFR because the afferent arterioles, and also efferent arterioles, will constrict in response to the increased sympathetic nerve activity..

Front 11

increased activity in sympathetic nerves does what to the GFR?

Back 11

tends to decrease GFR because the afferent arterioles, and also efferent arterioles, will constrict in response to the increased sympathetic nerve activity..

Front 12

vasodilation of the efferent arterioles does what to GFR?

Back 12

vasodilation of the efferent arterioles will increase RBF, but decrease GFR.

Front 13

13. Dilation of the efferent arterioles would result in an initial increase in
A. hydrostatic pressure in Bowman’s space
B. hydrostatic pressure in the glomerular capillaries
C. GFR
D. blood flow through the glomerular capillaries
E. Both C and A

Back 13

13. D. Blood flow would increase (as it does with vasodilation anywhere in the circulatory system).

Front 14

Dilation of the efferent arterioles would result in an initial_______ in hydrostatic pressure in the glomerular capillaries

Back 14

decrease

Front 15

Dilation of the efferent arterioles would result in an initial _______ in GFR

Back 15

decrease

Front 16

Dilation of the efferent arterioles would result in an ____________ in hydrostatic pressure in Bowman’s space

Back 16

no change

Front 17

14. Autoregulation in the kidney
A. maintains a high RBF even during hemorrhage
B. is mediated primarily by reflexes in the sympathetic nervous system
C. is mediated in part by intrinsic activity in the afferent arteriolar smooth muscle
D. is mediated primarily by a change in the oncotic pressure of Bowman’s space
E. is a reflex unique to the kidney

Back 17

14. C. Autoregulation is due to local effects, not sympathetic nervous

Front 18

Does Autoregulation in the kidney maintain a high RBF even during hemorrhage?

Back 18

During hemorrhage, the afferent arterioles are maximally dilated, but still cannot maintain RBF

Front 19

Is Autoregulation in the kidney mediated primarily by reflexes in the sympathetic nervous system?

Back 19

Autoregulation is due to local effects, not sympathetic nervous system

Front 20

Is Autoregulation in the kidney mediated primarily by a change in the oncotic pressure of Bowman’s space?

Back 20

Oncotic changes in the Bowman’s space (the ultrafiltrate) are not part of this reflex

Front 21

Is Autoregulation in the kidney a reflex unique to the kidney?

Back 21

There are other organ systems with autoregulation – both the heart and the brain

Front 22

15. Tubuloglomerular feedback compensation to a decrease in arterial blood pressure will include all of the following EXCEPT
A. compensation is initiated by a decrease in the delivery rate of NaCl in the tubular fluid near macula densa cells
B. compensation includes release of a signal by the macula densa cells
C. the macula densa signal will produce relaxation in the afferent arteriolar smooth muscle
D. the result of compensation will be a decrease in GFR.

Back 22

15. D. Tubuloglomerular feedback is the feedback from the macula densa cells onto the smooth muscle of the afferent arteriole.

Front 23

What type of feedback helps maintain a constant rate of delivery of NaCl to the macula densa, and therefore, to the rest of the tubule.

Back 23

Tubuloglomerular feedback

Front 24

If the GFR of Tubuloglomerular feedback is high, then the delivery rate will be ……and the reflex will compensate by……?

Back 24

high

reducing the GFR.

Front 25

The compensation of reducing the GFR when Tubuloglomerular feedback is high is mediated by?

Back 25

vasoconstricting the afferent arteriole, thus lowering the GFR.

Front 26

If the GFR of ubuloglomerular feedback delivery rate is low, what happens?

Back 26

afferent arteriole will dilate, and GFR will increase.

Front 27

The reflex from GFR of Tubuloglomerular feedback delivery is mediated by?

Back 27

signals sent from the macula densa to the smooth muscle of the afferent arteriole.

Front 28

Although the macula densa cells also directly affect JG release of renin, the tubuloglomerular reflex refers to ?

Back 28

the local effect of locally delivered NaCl in the tubule on the afferent arteriole for that same tubule.

Front 29

16. During hemorrhage,
A. Fluid shifts from the intracellular to the extracellular compartment
B. GFR is maintained at a normal level by autoregulation
C. Increased sympathetic nerve activity decreases renal plasma flow
D. renin secretion decreases
E. Na+ and water excretion increase

Back 29

16. C

Front 30

During hemorrhage, does fluid shifts from the intracellular to the extracellular compartment?

Back 30

No. Hemorrhage is an iso-osmotic loss of ECF, so there would be no shift from intracellular to extracellular compartments

Front 31

During hemorrhage, is GFR is maintained at a normal level by autoregulation?

Back 31

No. Severe drops in blood pressure are outside the limits of autoregulation, so GFR would fall

Front 32

During hemorrhage, does renin secretion decreases?

Back 32

No. Renin secretion increases, not decreases

Front 33

During hemorrhage, does Na+ and water excretion increase?

Back 33

No. Restoring ECF and therefore blood pressure will only occur if the loss of Na+ and water from the extracellular compartment is reduced, not increased

Front 34

17. An increase in mean arterial pressure would produce all of the following EXCEPT:
A. GFR would increase initially
B. The rate of NaCl delivery in tubular fluid at the macula densa would increase
C. afferent arterioles would be stretched
D. JG cells would be stretched
E. renin secretion by the JG cells would increase

Back 34

17. E

An increase in mean pressure will increase hydrostatic pressure, and produce an initial increase in GFR. There would also be an increased rate of delivery of NaCl to the macula densa (because the GFR increase), the arterioles would be stretched by the pressure. JG cells are embedded in the wall of the afferent arteriole, and they also would be stretched, and do sense that stretch. However, the increased stretch of the JG cells, the increased delivery of NaCl to the macula densa would both decrease the secretion of renin (remember that ultimately, renin increases will increase systemic blood pressure).

Front 35

Would renin secretion would increase or decrease

Increased NACl sensed by macula densa cells

Back 35

Decrease

Increased Na+ sensed by macula densa cells results from an increased GFR. The macula densa cells, in addition to having an effect on afferent arteriolar smooth muscle, also have an effect on the JG cells. The increased NaCl sensed by macula densa cells will result in a decrease in renin secretion, and this will decrease the aldosterone, and finally the Na+ reabsorption by the tubules.

Front 36

Would renin secretion would increase or decrease?

Increased sympathetic nerve stimulation

Back 36

increase

Sympathetic nerves directly stimulate renin secretion from JG cells; an increase in nerve stimulation will increase renin release. Sympathetic stimulation will tend to increase during a fall in blood pressure.

Front 37

Would renin secretion would increase or decrease

Decreased stretch sensed by JG cells

Back 37

Increase

The JG cells are positioned around the afferent arteriole, and will be stretched when pressure in that arteriole increases, and stretched less when the pressure in the arteriole decreases. Decreased stretch sensed by the JG cells therefore corresponds to a decreased pressure in the arteriole. The JG cells will secrete more renin, which will help restore pressure.

Front 38

Would renin secretion would increase or decrease

Increased levels of ANP

Back 38

Decrease

ANP is released by cells of the atrium in response to stretch of the atrium (by the blood filling the atrium). ANP inhibits renin release.

Front 39

19. PAH is used to measure renal plasma flow because
A. it is distributed within the plasma, and within the cytoplasm of the blood cells
B. all of the PAH that enters the glomerular capillaries is filtered
C. PAH is entirely reabsorbed
D. the PAH that does not get filtered enters the tubules by way of secretion
E. it has no effect on tubuloglomerular feedback

Back 39

19. D. the PAH that does not get filtered enters the tubules by way of secretion

Front 40

PAH will enters?

Back 40

the arteries of the kidney, and the glomerular capillary.

Front 41

In the peritubular capillaries, all of the PAH present will …………….., so that the blood leaving the peritubular capillaries, and entering the renal veins, will contain_______.

Back 41

be secreted
no PAH

Front 42

Within the glomerular capillary, some of the PAH will be …………..while the rest will continue into…………..

Back 42

filtered and enter the tubular fluid

the efferent arteriole, and the peritubular capillaries

Front 43

Inulin PAH
Plasma .6 mg/dl .004 mg/ml
Urine 3.0 mg/ml 1.2 mg/ml
Urine flow = 2ml/min

20. The excretion rate of PAH is
A. 2.4mg/min
B. 2.4mg/ml
C. 1.2mg/min
D. 1.2mg/ml
E. .004 mg/ml

Back 43

A. Excretion rate of anything is = (concentration in the urine) * (rate of urine flow) = (mg/ml * ml/min), the excretion rate of PAH = (1.2mg/ml) * (2ml/min) = 2.4mg/min.. Excretion rate should always have the units of mass/time

Front 44

Inulin PAH
Plasma .6 mg/dl .004 mg/ml
Urine 3.0 mg/ml 1.2 mg/ml
Urine flow = 2ml/min
excretion rate 27 = 2.4mg/min

21. The renal plasma flow for this individual is:
A. 100 ml/min
B. 600 ml/min
C. 2 ml/min
D. 60 ml/min
E. 125 ml/min

Back 44

21. B..

Calculating RPF:
amount in = p[PAH] * RPF = amount out = u[PAH] * V
RPF = (U[PAH] * V)/ P[PAH]
You just calculated the excretion rate (U[PAH] *V) in problem 27 = 2.4mg/min
RPF = (2.4mg/min)/ (.004mg/ml)
= 600ml/min

Flow rate should always have the units of volume/time

Front 45

PAH is the substance we use to measure RPF for 2 reasons:

Back 45

First: it is filtered, and that filtered material is excreted (not reabsorbed),

Second: the PAH that was not filtered is secreted as it passes through the peritubular capillaries, and ends up excreted.

Front 46

Inulin PAH
Plasma .6 mg/dl .004 mg/ml
Urine .3 mg/ml 1.2 mg/ml
Urine flow = 2ml/min

22. The GFR for this individual is:
A. 125 ml/min
B. 600 ml/min
C. 2 ml/min
D. 60 ml/min
E. 100 ml/min

Back 46

E. GFR is calculated either from creatinine or inulin values. In this case, you were given values for inulin. The calculation is the same as above: the amount in/ time = amount out/time. In this case, the amount in/time is the filtration rate or GFR. The amount out/time is the excretion rate of inulin.

Amt in/time = P[inulin] * GFR
Amt out/time = U[inulin] * V
GFR= (.3 mg/ml * 2ml/min)/( .6mg/dl)
= 1dL/min or 100ml/min

The GFR is a flow rate, and should have the units of volume/time, just as the RPF

Front 47

Inulin PAH
Plasma .6 mg/dl .004 mg/ml
Urine .3mg/ml 1.2 mg/ml
Urine flow = 2ml/min
RPF = 600ml/min

23. The hematocrit for this individual is 40. What is the renal blood flow?

Back 47

Recall from Lecture 1 that the plasma volume = (1-hematocrit%) * blood volume

Similarly, renal plasma flow = (1-hematocrit%) renal blood flow

So renal blood flow = renal plasma flow / (1-hematocrit%)

Using the answer from question 21, RPF = 600ml/min

Renal blood flow = (600ml/min)/ .6 = 1000ml/min or 1L/min

Blood volume should be > plasma volume because blood includes both the plasma and the cells

Front 48

24. You inject PAH intravenously, but some of the solution enters the interstitium. The calculated RPF will be greater than or less than the actual value?

Back 48

This problem is similar to question 30, problem set 1, in that you need to think about the what happens to a volume measurement when some of the indicator escapes into another compartment. In this case, PAH is normally confined to the plasma compartment, so that the flow rate measured is the plasma volume per minute. If some of the PAH actually enters the interstitium, then the plasma concentration you measure will be lower than it should be, and you will underestimate the plasma volume, and the plasma flow rate.

Front 49

25. Using inulin will yield a more accurate measurement of GFR than using creatinine because
A. creatinine is not freely filtered
B. inulin is entirely reabsorbed
C. creatinine is slightly secreted
D. inulin is slightly secreted
E. inulin is both reabsorbed and secreted

Back 49

C. Both inulin and creatinine are freely filtered, but creatinine is slightly secreted, so inulin will give the more accurate result.

Front 50

Kidneys do what to maintain water and electrolyte balance?

Back 50

filter the plasma, then return all of the nutrient, and enough of the water and electrolytes

Front 51

All of these processes to maintain water and electrolyte balance done by the Kidneys depends on _________________________ that is maintained by the kidney through the cooperative events of ____________________________________

Back 51

the water and electrolyte balance

glomerular function, tubular secretion, and tubular reabsorption.

Front 52

Understanding the normal function of the kidney requires ………. and ……………………..

Back 52

an understanding of the relationship between renal blood flow and glomerular filtration,

a quantitative understanding of renal transport processes and how they are determined.

Front 53

Filtration is the formation of?

Back 53

the ultrafiltrate

Front 54

With permselectivity, what determines the size of charged and uncharged molecules normally capable of being filtered?

Back 54

The slit size (between processes of the podocytes) and molecular composition of the basal lamina

Front 55

Net filtration pressure =

ΔP is called Hydrostatic pressure difference

Back 55

ΔP (transcapillary hydrostatic pressure) – Δπ (transcapillary oncotic pressure)

Front 56

ΔP = formula

Back 56

Pgc-Pbs = (hydrostatic pressure in glomerular capillary – hydrostatic pressure in Bowman’s space)

Front 57

Δπ is called?

Back 57

Oncotic pressure difference

Front 58

Δπ = formula

Back 58

Oncotic pressure difference= πgc – πbs = (oncotic pressure in glomerular capillary – oncotic pressure in Bowman’s space)

Front 59

Oncotic pressure is usually zero within?

Back 59

Bowman’s capsule

Front 60

Oncotic pressure rises as the blood finishes going through the glomerular capillaries and enters the efferent arteriole.. why?

Back 60

Water has entered Bowman’s space

Front 61

The net force favors filtration along the entire length of the capillaries: How does this differ from other capillaries?

Back 61

Different than normal (?)

Front 62

The hydrostatic pressure in the glomerular capillaries is regulated by?

Back 62

two separate sets of arterioles:
afferent and efferent

Front 63

Where are two major drops in resistance in Hydrostatic pressure:

Back 63

across the afferent arteriole, and across the efferent arteriole.

Front 64

Arterioles are a primary target for factors changing _______.

Back 64

total resistance.

Front 65

How does this pattern of pressure drop compare to the site of pressure drops in the rest of the vascular system?

Back 65

???

Front 66

Filtration is favored in what capillary system?

Back 66

Glomerular capillaries

Front 67

Reabsorption is favored in what capillary system?

Back 67

Peritubular capillaries

Front 68

Filtration rate for entire kidney = formula

Back 68

Kf [(Pgc – Pbs) - πgc] =GFR

Front 69

Kf [(Pgc – Pbs) - πgc] =GFR =

Back 69

The volume of filtrate formed per unit time is the GFR.

Front 70

Kf of the Filtration rate for entire kidney is the?

Back 70

filtration coefficient; includes the total surface area for filtration,

Front 71

Kf of the filtration rate for entire kidney decreases if?

Back 71

substantial numbers of nephrons no longer function.

Front 72

The excretion of salt and water is greatly affected by?

Back 72

changes in GFR, so the regulation of GFR is crucial to kidney function. GFR is not constant

Front 73

The excretion of salt and water is greatly affected by changes in GFR, so the regulation of GFR is crucial to?

Back 73

kidney function.

Front 74

GFR is or is not constant

Back 74

Is not constant

Front 75

During each pass through the kidney, how much blood is filtered

Back 75

only a fraction

Front 76

Filtration fraction = formula

Back 76

GFR/RPF

Front 77

Normally, renal plasma flow (RPF)is about ?? mL/min.

Back 77

600 mL/min.

Front 78

Typical GFR= about ? mL:/min

Back 78

125

Front 79

If renal plasma flow (RPF)is about 600mL/min. and typical GFR= about 125 mL:/min, what does this mean?

Back 79

This means that, of the 600mL/min entering the
afferent arterioles, 125mL/min are filtered and enter the
tubules, while the remaining 485mL/min enter the efferent
arterioles.

Front 80

Filtration fraction = formula
and avg. amount filtered

Back 80

GFR/ RPF

about 20%

Front 81

A young woman suffers from severe back pain, and her physician discovers a large kidney stone (crystal of calcium oxalate) blocking one of her ureters. What effect would this kidney stone have on her GFR?

Back 81

The GFR will decrease because ΔP (Hydrostatic pressure difference) will decrease because PBS (hydrostatic pressure in Bowman’s space) increased

Front 82

The smooth muscle of arterioles is a target of ………… & …………. that
change …….

Back 82

various neural and hormonal signals

the resistance of the arterioles.

Front 83

The resistance of afferent and efferent arterioles can be _____, with different effects on ??, ??, & ??

Back 83

independently regulated

RBF (renal blood flow) and GFR, and filtration fraction (FF)

Front 84

Increase afferent arteriole resistance (vasoconstrict afferent arteriole smooth muscle) will have what effects on RBF, PGC, and GFR?

Back 84

RBF - Decrease
Pgc - Decrease
GFR - Decrease

Front 85

Δ afferent arteriole resistance, what two will have the same effects: RBF, PGC, & GFR

Back 85

RBF and GFR

Front 86

With Δ efferent arteriole resistance, what two will have the opposite effect on each other: RBF, PGC, & GFR

Back 86

RBF and GFR

Front 87

Any restriction or resistance will do what to the RBF?

Back 87

Will restrict RBF

Front 88

2. Increase efferent arteriole resistance (vasoconstrict efferent arteriole smooth muscle) will have what effects on RBF, PGC, and GFR?

Back 88

RBF - Decrease
Pgc - Increase
GFR - Increase

Front 89

3. Decrease efferent arteriole resistance (vasodilate efferent arteriole smooth muscle) will have what effects on RBF, PGC, and GFR?

Back 89

RBF - Increase
Pgc - Decrease
GFR - Decrease

Front 90

Decrease afferent arteriole resistance (vasodilate afferent arteriole smooth muscle) will have what effects on RBF, PGC, and GFR?

Back 90

RBF - Increase
PGC - Increase
GFR - Increase

Front 91

Changes of both afferent and efferent arteriolar resistance often affect?

Back 91

Major hormones that influence RBF and GFR

Front 92

What is the Stimulus, Action at kidney, Effect on RPF, & Effect on GFR of Atrial natriuretic peptide (ANP)?

Back 92

Stimulus: increased blood volume

Action at kidney: Vasodilation (afferent>efferent)

Effect on RPF: Increased effect

Effect on GFR: Increased effect

Front 93

What is the Stimulus, Action at kidney, Effect on RPF, & Effect on GFR
of Sympathetic nerve?

Back 93

Stimulus: decreased ECF (extracellular fluid volume)

Action at kidney: Vasoconstriction (afferent>efferent)

Effect on RPF: Decreased effect

Effect on GFR: Decreased effect

Front 94

What is the Stimulus, Action at kidney, Effect on RPF, & Effect on GFR of Angiotensin II (high dose)?

Back 94

Stimulus: decreased ECF (extracellular fluid volume) and increased renin
Action at kidney: Vasoconstriction (afferent>efferent)
Effect on RPF: Decreased effect
Effect on GFR: Decreased effect

ECF = extracellular fluid volume

Front 95

renin is secreted by?

Back 95

Juxtaglomerular cells

Front 96

rennin catalyzes the conversion of _____ to ________ .

Back 96

angiotensin I
angiotensin II

Front 97

an increase in renin secretion will __________ angiotensin II

Back 97

increase

Front 98

Changes in GFR have significant changes in the excretion of?

Back 98

Na+ and other solutes

Front 99

Changes in GFR have significant changes in the excretion of Na+ and other solutes. However, GFR normally does not vary as widely as the mean arterial pressure due to?

Back 99

intrinsic mechanisms within the kidney

Front 100

Within this range of autoregulation, the RPF, GFR, and FF are ______, even though the mean arterial blood pressure ________.

Back 100

constant

is changing

Front 101

When the GFR is increased, what happens toward macula densa cells?

Back 101

Increased rate of NaCl to Mecula Densa cells

Front 102

What happens during a hemorrhage?

Back 102

Decrease in blood volume, and blood pressure but no change in osmolality of ECF or ISF.


Increase in smooth muscle contraction, especially at afferent arteriole (due to high levels, related to severe blood loss)

Front 103

During a hemorrhage, what is the process from sympathetic outflow to sympathetic outflow to aldosterone

Back 103

Huge increase in sympathetic outflow will decrease RBF and GFR;

Huge increase in sympathetic outflow will directly increase in renin secretion (JG cells);

An increase in renin secretion will increase angiotensin II and increase aldosterone

increased angiotensin II and increased aldosterone will increase Na+ reabsorption

Front 104

During a hemorrhage, Decrease in RPF and GFR will _______ in Na+ and water excretion

Back 104

Decrease

Front 105

During a hemorrhage, a decrease in ECF volume will _______ ANP (atrial natriuretic peptide)

Back 105

Decrease

Front 106

During a hemorrhage, large decreases in ECF volume will _________ vasopressin (ADH)

Back 106

Increase

Front 107

an increase in renin secretion will __________ angiotensin II

Back 107

increase

Front 108

Changes in GFR have significant changes in the excretion of?

Back 108

Na+ and other solutes

Front 109

Changes in GFR have significant changes in the excretion of Na+ and other solutes. However, GFR normally does not vary as widely as the mean arterial pressure due to?

Back 109

intrinsic mechanisms within the kidney

Front 110

Within this range of autoregulation, the RPF, GFR, and FF are ______, even though the mean arterial blood pressure ________.

Back 110

constant

is changing

Front 111

When the GFR is increased, what happens toward macula densa cells?

Back 111

Increased rate of NaCl to Mecula Densa cells

Front 112

What happens during a hemorrhage?

Back 112

Decrease in blood volume, and blood pressure but no change in osmolality of ECF or ISF.


Increase in smooth muscle contraction, especially at afferent arteriole (due to high levels, related to severe blood loss)

Front 113

During a hemorrhage, what is the process from sympathetic outflow to sympathetic outflow to aldosterone

Back 113

Huge increase in sympathetic outflow will decrease RBF and GFR;

Huge increase in sympathetic outflow will directly increase in renin secretion (JG cells);

An increase in renin secretion will increase angiotensin II and increase aldosterone

increased angiotensin II and increased aldosterone will increase Na+ reabsorption

Front 114

During a hemorrhage, Decrease in RPF and GFR will _______ in Na+ and water excretion

Back 114

Decrease

Front 115

During a hemorrhage, a decrease in ECF volume will _______ ANP (atrial natriuretic peptide)

Back 115

Decrease

Front 116

During a hemorrhage, large decreases in ECF volume will _________ vasopressin (ADH)

Back 116

Increase

Front 117

The kidneys receive almost __% of the cardiac output.

Back 117

20%

far more than is necessary to supply the metabolic needs of renal cells.

Front 118

All of the blood entering the kidney flows through ……….., and a fraction of this blood is filtered during …………

Back 118

the glomerular capillaries

the passage through the glomerulus

Front 119

…………….. is a crucial element in kidney function, and in the quantitative analysis of kidney function.

Back 119

Conservation of mass

Front 120

What is a good rule of thumb for measuring kidney fuction?

Back 120

Amount in = Amount out

(Conc. in the volume * volume/time ) going in = (conc. in the volume * volume/time ) going out

Front 121

Amount in = formula

Back 121

Pa[x] * RPFa Pa[x] = concentration in plasma in renal artery;

Front 122

What is this formula?

Pa[x] * RPFa Pa[x]

Back 122

concentration in plasma in renal artery;

RPFa = renal artery plasma flow

Front 123

RPF = formula
related to renal blood flow in the following way

Back 123

Volume of plasma = (1-hematocrit) * volume of blood
RPF = (1-hematocrit)* RBF

Front 124

There is only one way for substances to enter the kidney, but there are two possible ways for substances to exit the kidney. What are the two possible ways?

Back 124

Plasma Flow & Glomerular filtration rate

Front 125

Amount out = Formula

Back 125

Pv[x] * RPFv + U[x]* V

Pv[x] = plasma concentration in renal vein;
RPFv= renal venous plasma flow
U[x] = urine concentration
V= urine flow rate

Front 126

The conservation of mass of plasma flow (RPF) means that

Back 126

(input) = (output)

Input (X) of RPF formula via the renal artery

= P[x] * RPF mg/dL * dL/hour

Front 127

Output of RPF =

Back 127

urine + renal vein

Front 128

Output distribution will depend on whether:

Back 128

the solute is reabsorbed (into capillaries, and therefore entering venous
drainage),

secreted (leaving capillary and entering tubule) or

simply excreted without additional reabsorption or secretion

Front 129

What if Input (X) of RPF formula were freely filtered, and entirely secreted
Output would be?

Back 129

urine only

Front 130

if Input (X) of RPF formula were freely filtered, what would the formula be?

Back 130

Input (X) of RPF formula (freely filtered) = U[x] * V

V= volume urine/hour
= mg/dL * dL/hour

Front 131

What does this formula mean?
P[x] * RPF = U[x] * V

Back 131

In = Out

In: P[x] * RPF

Out: U[x] * V

Front 132

What is the formula for RPF?

Back 132

RPF= (U[x] * V) / P[x]

Front 133

What is PAH?

Back 133

PAH (p-aminohippurate) is an organic substance, not
endogenous, but extremely useful in determining RPF.

Front 134

At low concentrations PAH is essentially entirely secreted __________, so that all of the PAH entering the kidney is removed, and the concentration of PAH in the renal vein is ____

Back 134

by the tubules

0.

Front 135

What is the RPF from the following variables?

P[PAH] = 2.0 mg/dL

U[PAH] = 226mg/dL

V= 5.3ml/min

Back 135

RPF = (U[x] * V) / P[x]

226 mg/dL x 5.3ml/min x (1dL/100ml) / 2.0 mg/dl =

11.98 mg/dL / 2.0 mg/dL = 5.99 dL/min

Front 136

In order to measure GFR, we can apply conservation of mass, and use a substance, y that is ........

Back 136

filtered by each nephron, but is neither reabsorbed nor secreted:

Front 137

By conservation of mass of GFR,

Amount in = ??

Amount in = amount filtered = ??

Amount out equation = ??

GFR = ??

Back 137

amount out

P[y] * GFR

U[y] * V

U[y] * V / P[y]

Front 138

In order to measure GFR, we can apply conservation of mass,and use a substance, y that is filtered by each nephron, but is neither reabsorbed nor secreted: What is one good example of substance Y?

Back 138

Inulin: one substance that fulfills these requirements. It is not endogenous, inert, and eliminated solely via the urine without any additional secretion by the tubules.

Front 139

What is the GFR from the following variables?

P[ in] = 94.7 mg/dL
U[in] = 3500 mg/dL
V= 2.3ml/min
GFR = ??

Back 139

GFR= U[in] * V / P[in]

3500 mg/dl x 2.3 ml/min x (1 dL/100 mL) / 94.7 mg/dL = .805 mg/min / 94.7 mg = .85 mg/min = 85 ml/min

Front 140

Practically, inulin is difficult to use in a clinical setting because it requires IV administration for a period long enough to excrete a reasonable volume of urine. Instead, clinical measurements of GFR are estimated from?

Back 140

an endogenous substance, creatinine.

Front 141

What is creatinine?

Back 141

Creatinine is a waste product related primarily to muscle activity.

Front 142

Creatine is synthesized in ........ , and excreted ........... . It is taken up by skeletal muscle, and reversibly converted to .............:

Back 142

the liver

into the plasma

phosphocreatine

Front 143

Creatine <~> phosphocreatine
Involves?

Back 143

Creatine kinase and ATP converts to ADP+Pi

Front 144

The reaction Creatine <~~> phosphocreatine is coupled to the formation of ……… and the pool of phosphocreatine acts as ……….

Back 144

ATP,

a high energy storage for muscle.

Front 145

Creatine is metabolized to a waste product, ________ and is then released into the blood.

Back 145

Creatinine

Front 146

The plasma levels of creatinine are fairly constant for an individual, and are generally related to ?

Back 146

Creatinine

the muscle mass of the individual (although there can be transient changes due related to diet)

Front 147

What are the plasma levels of creatine in males and females

Back 147

Males: 62-121 mM/L

Females 44-110 mM/L