Brainscape's Knowledge GenomeTM

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


See full index

Physio II (Exam 3) > Topic 8 B What happens in each segment > Flashcards

Topic 8 B What happens in each segment Flashcards

1
Q

Proximal Tubule % of filtered load of sodium & water reabsorbed

A

65%

Little less % for chloride
Quantity can be increased or decreased as needed

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

Proximal Tubule - mitochondria amount? why?

A

Contain large number of mitochondria
to support extensive active transport
activity

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

Proximal Tubule Ultrastructure Luminal border contains what?

A

extensive number of protein carrier molecules

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

Proximal Tubule Ultrastructure Co-transport of what?

A

amino acids and glucose

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

Proximal Tubule Ultrastructure Counter transport of what?

A

hydrogen ions (move a large quantity of hydrogen ions against small hydrogen ion gradient

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

Proximal Tubule Ultrastructure Basolateral border contains extensive amounts of what?

A

extensive amount of N-K ATPase

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

First half of Proximal tubule- co-transport of what ? what does it do to Na levels?

A

Extensive co-transport of sodium with glucose and amino acids
Sodium reabsorption carries glucose, bicarb, organic ions leaving chloride resulting in increasing [Cl-]

105 mEq/L increases to 140 mEq/L

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

Second half of Proximal Tubule –

Cl concentration ?

A

High chloride concentration favors chloride diffusion

Some movement may occur through specific chloride channels

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

Second half of Proximal Tubule –

Electrochemical gradient created by reabsorption how??

A

Most glucose & amino acids have been reabsorbed–sodium reabsorption drives chloride reabsorption
Electrochemical gradient

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

Many end products of metabolism are secreted by proximal tubule (4)

A

Bile salts
Oxalate
Urate
Various catecholamines

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

drugs & toxins secreted in proximal tubule (2)

A

Penicillin

Salicylates

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

Para-aminohippuric acid secreted in proximal tubule – what % used to determine what?

A

90% of PAH in renal blood flow is removed

Can be used to determine renal blood flow

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

Thin descending and ascending LOH segments characteristics ? (4)

A

Thin epithelial membrane
No brush border
Few mitochondria
Minimal metabolic level

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

Thin descending segment of LOH - permeability to H2O and solutes?

A

Highly permeable to water

Moderately permeable to most solute

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

Thin descending segment of LOH - diffusion?

A

Allows diffusion of water and solutes

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

Thin descending segment of LOH - reabsorption %?

A

No active reabsorption

20% of water reabsorption occurs in the loop of Henle

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

Thin ascending segment - H2O permeability?

A

impermeable to water

Part of mechanism for concentrating urine

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

Thick Ascending LOH - epithelial cells characteristics?

A

Thick epithelial cells with high concentration of mitochondria

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

Thick Ascending LOH - what % of sodium, chloride, & potassium reabsorbed is filtered load?

A

(Approx 25% of filtered load)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Thick Ascending LOH - water permeability ?

Fluid is what?

A

Impermeable to water

As solute reabsorb luminal solute concentrations drop especially since water NOT reabsorbed–Fluid very dilute

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Sodium Reabsorption is driven by what in basolateral border of tubule cells?

A

N-K ATPase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Two transport mechanisms move sodium from tubular lumen (in LOH)

A
  • 1 Na-2Cl-1K co-transport mechanism

- Na-H counter-transport mechanism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Primary transport means of moving sodium out of lumen into tubular cells (in LOH)

A

1 Na-2Cl-1K co-transport mechanism
Potassium reabsorbed AGAINST potassium concentration gradient
Cl-& K+ diffuse out of cell into renal interstitial fluid via specific ion channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What loop diuretics inhibit the action of the 1Na-2Cl-1K co-transport mechanism out of lumen into tubular cells (in the LOH)

A

furosemide, ethacrynic acid, bumetanide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

LOOP Diuretics - cause less sodium reabsorption does what to H2O and K

A

Less sodium reabsorption–less H2O reabsorption in later segments of the nephron
Less sodium reabsorption–less K reabsorption with potential loss of K

26
Q

Na-Cl-K co-transport mechanism is what?

in LOH lumen

A

is isoelectric

BUT K able to diffuse back into lumen via potassium channels creating +8 mV positive charge in tubule lumen

27
Q

Electrical gradient in LOH lumen and tubular cells drives diffusion of what?

A

Electrical gradient drives diffusion of Na+, K+, Mg++ & Ca++ into the renal interstitial space via the tight junctions (paracellular diffusion)

28
Q

Macula densa is where??

A

first part of distal tubule

Part of juxtaglomerular complex

29
Q

Macula densa provides what?

A

Provides feedback control for GFR and blood flow (for this nephron)

30
Q

What is the segment after the macula densa in the distal tubule ? and reabsorption?

A

High convoluted Segment

Solute reabsorption–no water reabsorption

31
Q

The High Convoluted Segment is also known as what segment of the distal tubule?

A

Diluting segment of distal tubule

32
Q

In Early Distal Tubule what % of filtered load for sodium & chloride reabsorbed

A

5%

33
Q

In Early Distal Tubule reabsorbed is driven by what?

A

Driven by Na-K ATPase in basolateral border of tubular cells

34
Q

In Early Distal Tubule Na-Cl co-transport mechanism moves Na and Cl where?

A

mechanism moves Na+ and Cl-into cell down [Na+]

Chloride diffuses out of cell via chloride specific channels

35
Q

Thiazide diuretics inhibit what mechanism? (in the early distal tubule)

A

Na-Cl co-transport mechanism

Reduces sodium and chloride reabsorption and ultimately water reabsorption in later segments of nephron

36
Q

Late Distal Tubule & Cortical Collecting Tubule

Membranes permeability to urea?

A

impermeable to urea
All urea entering exits to collecting duct to be excreted
Some reabsorption of urea will occur in medullary collecting ducts

37
Q

Late Distal Tubule & Cortical Collecting Tubule

Na and K secretion is controlled by what?

A

secretion controlled by various hormones but especially by aldosterone

38
Q

Late Distal Tubule & Cortical Collecting Tubule

H+ ions secretion?

A

Able to secrete hydrogen ions against large concentration gradient (1000:1)
Proximal tubule moves hydrogen ions against small gradient (4 to 10:1)

39
Q

Water permeability controlled by concentration of what?

A

antidiuretic hormone (ADH, aka vasopressin)

No ADH-no water permeability–excrete dilute urine
Increased conc of ADH increase permeability of water & decrease the volume of urine and increase the conc of the urine

40
Q

Two types of cells in late distal and cortical collecting duct

A

Principal cells

Intercalated cells

41
Q

Principal cells in late distal and cortical collecting duct do what?

A

Reabsorb sodium & water

Secrete potassium

42
Q

Intercalated cells in late distal and cortical collecting ducts do what?

A

Reabsorb potassium

Secrete hydrogen

43
Q

Principal Cells - what pump drives activity? what border is it on? which way does everything go?

A

Na-K ATPase in basolateral borders of tubule cells drives activity
Na follows concentration gradient–diffuses through sodium specific channels
K follows concentration gradient out of cell into tubular lumen via potassium specific channels

44
Q

Aldosterone antagonists is what kind of diuretic ?

A

K sparing diuretic

Works in Late distal and cortical collecting duct

45
Q

Aldosterone antagonists work on what receptors?

A

Mineralocorticoid receptor antagonists

Work in Late distal and cortical collecting duct

46
Q

Aldosterone antagonists do what?

2 examples?

A

Compete with aldosterone receptor sites which inhibits Na reabsorption & K secretion
Spironolactone & eplerenone

47
Q

Na channel blockers work how?

2 examples?

A

Inhibit entry of sodium into cell which reduces amount of sodium transported by Na-K ATPase
Also reduces secretion of potassium as action of Na-K ATPase decreases
Amiloride & triamterene

48
Q

Na channel blockers are what kind of diuretic?

A

K sparing diuretic

ex: Amiloride and Triamterene
Work in Late distal and cortical collecting duct

49
Q

Intercalated Cell Activity what is H+ ions secretion controlled by?
in Late distal and cortical collecting duct

A

Secretion controlled by H-ATPase transporter

50
Q

In the Late distal and cortical collecting duct, Intercalated Cell Activity – the H-ATPase transporter must have have the presence of what for conversion of CO2 and H2O into H+ ions and HCO3?

A

Presence of carbonic anhydrase allows conversion of CO2 and H2O to hydrogen ions and bicarb ions

51
Q

In the Late distal and cortical collecting duct, Intercalated Cell Activity – how is Chloride secreted ?

A

Chloride also secreted following electrochemical gradient

52
Q

In the Late distal and cortical collecting duct, Intercalated Cell Activity - Bicarb is reabsorbed using what transport mechanism?

A

Bicarb reabsorbed using Cl-HCO3-counter-transport mechanism following the Cl-gradient into the cell

53
Q

In the Late distal and cortical collecting duct, Intercalated Cell Activity what is moved freely between cell and interstitial fluid?

A

CO2 moved freely between cell and interstitial fluid

54
Q

Meduallary Collecting Ducts reabsorb what % of filtered water and Na?

A

Reabsorb <10% of filtered water and sodium

55
Q

Meduallary Collecting Ducts determines what?

A

Determine final concentration of solutes and urine concentration

56
Q

Meduallary Collecting Ducts, Water permeability controlled by what?

A

ADH

57
Q

Meduallary Collecting Ducts how is Urea reabsorbed?

A

Urea is reabsorbed via specific urea transporters which moves urea into the interstitial spaces thus affecting osmolarity

58
Q

Meduallary Collecting Ducts secrete what ion?

A

Secretes hydrogen ions (like cortical collecting tubule)

59
Q

Change in solute concentration depends

on what vs what?

A

rate of reabsorption (secretion) versus rate of water reabsorption

60
Q

On the squiggly graph with all the different solutes – what does inulin’s line represent?

    • what does a conc of 3 mean?
    • what does a conc of 125 mean?
A

Inulin neither secreted or reabsorbed
provides indication of water reabsorption
Inulin conc of 3 means that 1/3 of water remains in tubule (2/3 has been reabsorbed)
Inulin conc of 125 means 1/125 of water remains while 124/125 has been reabsorbed

Physio II (Exam 3) (6 decks)

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