Brainscape's Knowledge GenomeTM

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


See full index

PHAR226 > Renal Clearance > Flashcards

Renal Clearance Flashcards

1
Q

What is the basic functional unit of the kidney?

A

nephron

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

What is the role of the glomerulus?

A

filters blood

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

What is the role of the tubules?

A

reabsorbs water and filtered solutes
allows exchange of solutes to and from systemic circulation

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

What is the value for renal blood flow?

A

1200ml/min
-10% is filtered, so GFR=120ml/min

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

What are the functions of the kidney?

A

excretory
-filtration, secretion, reabsorption
endocrine
-renin, PGs, kinins, erythropoietin
metabolic
-vit D activtation, gluconeogenesis, insulin metabolism
renal function=excretion+endocrine+metabolic

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

Describe the excretory function of the kidney.

A

regulates fluid, electrolyte, and acid-base balance
removes metabolic waste products & foreign chemicals from blood for urinary excretion

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

Differentiate between the afferent arteriole and efferent arteriole.

A

afferent: brings blood to glomerulus
efferent: takes blood away from glomerulus

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

What composes the filtrate?

A

water, glucose, electrolytes, small molecules, amino acids, urea, uric acid, creatinine
excludes proteins and large molecules like RBC

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

What is the driving force that produces filtrate?

A

hydrostatic pressure

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

What is reabsorption?

A

movement of substances out of the renal tubule back into the blood capillaries
-prevents loss of substances needed by body
-water, solutes like ions, aa, glucose

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

What is secretion?

A

movement of substances out of the blood and into the renal tubules
-diffusion or active transport

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

What is the primary organ of parent drug or drug metabolite excretion?

A

kidney

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

What state must drug be in to be filtered by the kidney?

A

unbound drug
-all unbound drug is filtered by the kidney, whether drug is excreted depends on the PC nature of the drug
–>lipophilic drug is not excreted as can be reabsorbed from urinary filtrate
–>polar drugs are typically excreted
–>MW<2,000g/mole are filtered

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

What is the equation for renal clearance?

A

Clr=fu(b) x Clgfr + Clts - Cltr

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

If GF is the only Clr mechanism, what does this mean for extraction ratio?

A

low extraction ratio
extraction ratio=rate of extraction/rate of presentation
=GFR/RBF=120ml/min/1200ml/min=0.1

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

How do we know if TS is involved?

A

Clr>fu(b) x CLlgfr

17
Q

What are the factors influencing glomerular filtration?

A

molecular size
plasma protein binding
glomerular integrity and total number of functioning nephrons
-diseases influence glomerular filtration

18
Q

What are the markers of GFR?

A

inulin (exogenous)
creatinine (endogenous)
both are not bound to plasma proteins and undergo only glomerular filtration
Clr of these cpds serves as a measure of Clgfr and as a measure of renal function

19
Q

When Clr is an important component of Cls, what is the relationship often seen between Clr and creatinine clearance?

A

proportional relationship between CrCl and Clr

20
Q

What is the Intact Nephron Hypothesis?

A

loss of either glomerular or tubular function means loss of of whole nephron function
all-or-nothing
-all renal excretory processes decline in parallel
-loss of a functional nephron is reflected in GFR
-if GFR is 20% of normal, then Clr is 20% of normal

21
Q

What is the result of active tubular secretion on Clr?

A

Clr to be greater than Clr due to GFR alone

22
Q

What kind of drugs undergo active tubular secretion?

A

drugs that are charged, neutral, or lipophilic

23
Q

Is tubular secretion saturable?

A

yes, alters Clr and no longer a constant

24
Q

How much filtrate is formed per day?

A

180L

25
Q

What kind of compounds undergo tubular reabsorption?

A

filtered endogenous compounds undergo active reabsorption (transporter-mediated)
-aa, fa, glucose, lactose, vitamins, minerals
filtered lipophilic drugs reabsorbed by passive diffusion (passive reabsorption)
-Clr minor elimination route

26
Q

When do we infer passive reabsorption is occuring?

A

Clr<fu(b) x Clgfr

27
Q

What are the physiological factors affecting TR?

A

urine concentration
-water reabsorption causes drug to concentrate in filtrate enhancing concentration gradient for passive reabsorption
urine flow
-affects Clr only for drugs that undergo extensive TR
-higher flow results in less TR (diuresis)
urine pH
-average is 6.3 but varies with time of day, diet, drugs
-pH partition hypothesis applies

28
Q

What is the effect on TR and Clr on a weak organic acid if urine is acidic or basic?

A

acidic:
-TR increases
-Clr decreases
basic:
-TR decreases
-Clr increases

29
Q

What is the effect on TR and Clr on a weak organic base if urine is acidic or basic?

A

acidic:
-TR decreases
-Clr increases
basic:
-TR increases
-Clr decreases

PHAR226 (12 decks)

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