Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

A&P Fall 24' > Vanders Renal Ch3 > Flashcards

Vanders Renal Ch3 Flashcards

1
Q

Define the term clearance in a biomedical context

A

The volume of plasma per unit time from which all of a specific substance is removed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is metabolic clearance rate?

A

The quantitative measure of how a substance is removed from the plasma by any of the body’s mechanisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Differentiate between general clearance and specific renal clearance

A

General clearance refers to removal by any means, while renal clearance is specifically by the kidneys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What information is required to calculate clearance?

A

Plasma concentration of the substance, urine concentration, and urine flow rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What criteria must a substance meet to be used as a measure of glomerular filtration rate (GFR)?

A

The substance must be freely filtered, not reabsorbed or secreted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which substances are commonly used to measure GFR?

A

Inulin and creatinine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the significance of inulin clearance?

A

It specifically indicates renal clearance and is used to measure GFR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Calculate the clearance of a substance given its excretion rate and plasma concentration

A

Clearance (Cx) = Excretion rate (Ux * V) / Plasma concentration (Px)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does a clearance greater than GFR indicate?

A

Net secretion of the substance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does a clearance less than GFR indicate?

A

Net reabsorption of the substance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the gold standard for measuring GFR?

A

Inulin clearance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the common method to measure GFR in patients?

A

Creatinine clearance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why does creatinine clearance slightly overestimate GFR?

A

A small amount of creatinine is secreted by the proximal tubule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the relationship between plasma creatinine concentration and GFR?

A

They vary inversely; as GFR decreases, plasma creatinine increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Fill in the blank: Plasma concentration of _______ is a practical indicator of GFR.

A

creatinine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

True or False: All substances used to measure GFR must be reabsorbed by the kidneys.

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the role of cystatin C in estimating GFR?

A

Cystatin C is produced at a constant rate and is cleared by glomerular filtration, reflecting GFR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the typical plasma concentration of creatinine in a healthy person?

A

About 1 mg/dL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What happens to plasma creatinine concentration if GFR decreases by 50%?

A

Plasma creatinine stabilizes at 2 mg/dL

20
Q

What is the significance of the clearance units?

A

They are expressed as volume per time, reflecting the volume of plasma cleared of a substance

21
Q

Describe the renal handling of inulin

A

Inulin is freely filtered, not reabsorbed or secreted, and all filtered inulin appears in the urine

22
Q

What does the clearance of para-aminohippurate (PAH) indicate?

A

It indicates effective renal plasma flow, as PAH is filtered and secreted

23
Q

What does a clearance equal to GFR indicate?

A

No net reabsorption or secretion has occurred

24
Q

What are some exogenous agents used to measure GFR?

A

125I-iothalamate, 59Cr-EDTA, 99mTc-DTPA

25
Q

What is the advantage of using cystatin C over creatinine for GFR estimation?

A

Cystatin C is less affected by muscle mass and is cleared more completely

26
Q

What does clearance express in the context of renal function?

A

The rate at which a substance is removed from the plasma and excreted in the urine

27
Q

What is the best measure of GFR?

A

Inulin clearance

28
Q

Which clearance can be used as an estimate of renal blood flow?

A

Para-aminohippurate clearance

29
Q

What is a practical measure of GFR?

A

Creatinine clearance

30
Q

Which two substances are clinically used as indicators of GFR?

A
  • Plasma creatinine concentration
  • Cystatin C
31
Q

What is renal scintigraphy used for?

A

Assessing the function of each kidney separately

32
Q

Fill in the blank: Renal clearance of any substance is calculated by a _______.

A

clearance formula relating urine flow to urine and plasma concentrations

33
Q

What happens to plasma creatinine levels when GFR is reduced?

A

Plasma creatinine stabilizes at a higher concentration

34
Q

True or False: Cystatin C levels are less affected by age, sex, race, and muscle mass than creatinine levels.

A

True

35
Q

What is the significance of an increasing plasma creatinine over time?

A

It is a red flag that there may be a renal problem

36
Q

What is the effect of large amounts of red meat on creatinine levels?

A

It may cause a transient increase in creatinine levels

37
Q

What can MAG3 clearance indicate about kidney function?

A

Deficient clearance indicates poor ability to clear creatinine and other organic waste

38
Q

What does a renogram plot represent?

A

Graphical plot of radioactive counts versus time

39
Q

What is the typical peak time for healthy kidneys in renal scintigraphy?

A

3 to 4 minutes

40
Q

What is the expected plasma urea concentration after 80% nephron destruction if initial concentration was 5 mmol/L?

A

25 mmol/L

41
Q

What is the relationship between MAG3 clearance and creatinine clearance?

A

MAG3 clearance is highly correlated with creatinine clearance

42
Q

Fill in the blank: Cystatin C measurements have not been shown to be superior to _______.

A

formula-adjusted estimations of kidney function based on creatinine measurements

43
Q

What factors are included in eGFR equations?

A
  • Age
  • Body size
  • Gender
  • Race
44
Q

True or False: Urea measurement is a more accurate indicator of GFR than plasma creatinine or cystatin C.

A

False

45
Q

What does the clearance formula relate to?

A

Urine flow to urine and plasma concentrations

46
Q

What does a slower rise in kidney counts during renal scintigraphy indicate?

A

Poor kidney performance

47
Q

What substance is cleared by the kidneys almost exclusively by secretion?

A

MAG3

A&P Fall 24' (27 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions