Brainscape's Knowledge GenomeTM

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


See full index

Renal > Kidney as a producer, excreter and regulator > Flashcards

Kidney as a producer, excreter and regulator Flashcards

1
Q

Erythropoeitin

A
  • Produced when fall in oxygen levels
  • Secreted by peritubular cells
  • Stimulates RBC production
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Vitamin D

A
  • Skin + UVB = cholecalciferol
  • Liver converts to calcidiol (25-hydroxycalciferol)
  • Kidney: converted to 1,25-dihydryoxycalciferol
  • Calcitriol increases Ca2+ by promoting GI absorption, decreasing renal excretion and stimulating bone reabsorption
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How does fluid travel in nephron

A

Blood, PCT, LOH, DCT, CD

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

Tight junctions in PCT, DCT, CD

A
  • Large number of proteins creates a barrier to water and dissolved particles
  • Loose in PCT
  • Tight in DCT
  • Very tight in CD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Journey through nephron

A
  • Afferent arteriole - Bowman’s capsule - filtrate - efferent removes unfiltered
  • Nephron transmits between cortex and medulla
  • Glomerulus - PCT - LOH - DCT - CT
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Cortical glomeruli

A

Dilute but don’t concentrate

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

Function of inter medullary glomeruli

A

Concentrate and dilute

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

Podocytes

A

negatively charged, cover glomerular capillaries, have small filtration channels

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

Glomerulus

A

Produces filtrate by high pressure system
Anions pass less easily than cations
Na+, HCO3-, glucose but no proteins

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

What is GFR?

A

Marker of renal function

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

How to calculate rate of filtration

A

Urine flow x urine concentration

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

Markers of renal function

A

creatinine (product of muscle metabolism, slight overestimation), cystatin C (produced by most cells) and inulin (plant extract, infuse to steady state)

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

How to calculate GFR

A

(UFR x Cu) / Cp

Cu = creatinine in urine, Cp is creatinine in plasma

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

When will GFR be proportional to 1/Cp

A

Creatinine production constant

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

What happens when arterial pressure falls?

A

Drop in RBF and GFR
Arteriole dilates, improving RBF
Efferent arteriole constricts, improving GFR

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

Function of adenosine

A

produced in hydrated state, constricts afferent arteriole to reduce GFR and inhibit renin release, switched off with reduced filtrate flow

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

Function of angiotensin ii

A

produced from renin cascade, constricts efferent arteriole to maintain GFR, leads to ATII inihibition in hypovolaemia

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

Function of PGE 2

A

roduced in DCT when filtrate flow decreased, dilates afferent arteriole to maintain RBF, cytoprotective to tubule, antagonises vasopressin, beware NSAIDs in hypovolaemia

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

Two types of auto regulation mechanisms

A

Myogenic and tubule-glomerular feedback

20
Q

3 types of tubule-glomerular feedback

A

Adenosine, angiotensin ii and PGE 2

21
Q

Function of PCT

A
  • Conservation of majority of useful filrate components
  • Reabsorbs Na+, HCO3- and glucose and water
  • At the end, [Na+] same as plasma, no HCO3- and no glucose
  • H2CO3 breaks down to produce the proton
  • Exchanges for Na+ in antiporter
  • Sodium leaves, water follows
  • Transport maximum of glucose is 2mmol/min, when this is reached, glycosuria results
22
Q

Function of LOH

A
  • Produced hypotonic tubular fluid and hypertonic interstitial fluid and some reabsorption of Na+, K+ and Cl-
  • At the end, extremes in osmolality (medulla interstitium is very high and tubular fluid is very low)
  • Mechanism: selective permeabilities to ions and water
  • Ascending limb: impermeable to water but permeable to ions, causing high concentration of ions in interstitial space
  • Fluid is progressively more dilute as you ascend
  • Ion reabsorption in ascending limb: Na+/K+ co-transporter, K+ into blood, Na+ leaves
23
Q

How does furosemide work

A

diuretic, blocks co-transporter of Na+ and K+ so none reabsorbed

24
Q

Characteristics of descending limb

A
  • Permeable to water, impermeable to ions
  • Water is lost via AQP1
  • Tubular fluid more concentrated coming down
25
Q

Where does water move in LOH

A

From descending LOH to ascending limb of vasa recta

26
Q

Why is water reabsorbed efficiently in CD

A

Hypertonic environment

27
Q

Function of DCT

A

Final regulation of sodium, potassium, hydrogen

28
Q

Function of principal cells

A

reabsorb sodium and secrete potassium, regulated by aldosterone

29
Q

Function of intercalated cells

A

reabsorb potassium and secrete hydrogen, driven by ATPase

30
Q

Stimuli of principal cells

A

Aldosterone, increased potassium, alkalosis, increased tubular flow

31
Q

Stimuli for intercalated cells

A

Acidosis, decreased potassium

32
Q

Function of CD

A

Final water regulation, regulated by ADH

33
Q

Aquaporins

A
  • Water channels
  • Narrow shape and charged walls
  • Positive in core
  • Over 8 sub-types
34
Q

Site and nature of AQP 1

A 
Site = PCT, descending LOH basal membrane
Nature = continuous water reabsorption
35
Q

Site and nature of AQP 2

A

Site: CD
Nature: response to ADH, variable water reabsorption

36
Q

Site and nature of AQP 3

A

Site: CD basal membrane
Nature: continuous water reabsorption

37
Q

Site and nature of AQP 4

A

Site: CD basal membrane
Nature: continuous water reabsorption

38
Q

How is water reabsorbed in CD

A
  • ADH released from posterior pituitary in response to hypothalamic osmoreceptors
  • ADH causes AQP2 to insert
  • 3 receptors - all G-protein
    3 receptor are V1a, 2 and 3
39
Q

Where is H+ secreted and HCO3 absorbed

A

PCT

40
Q

Which cells make final adjustments in DCT

A

Intercalated cells

41
Q

How is H= secreted and HCO3 reabsorbed

A

H2CO3 forms H+ and HCO3-
H+/Na+ moves hydrogen into lumen and Na+ into tubular cells
Na+/HCO3- co-transporter moves into blood

42
Q

Function of JGA

A
  • Between afferent arteriole and DCT
  • Senses decrease in pressure (granular cells) or decreased sodium tubular flow (macula densa cells)
  • Triggering of this apparatus leads to dilation of afferent arteriole (decreased adenosine and PGE2) and releases renin (also triggered by B1 stimulation)
43
Q

Function of AT 1

A

Acts on aldosterone = volume retention in kidneys

44
Q

Function of angiotensin ii

A

Vasopressin - water retention (V2) and vasoconstriction (V1a)

45
Q

Function of baroreceptors

A

Increase HR and vasoconstriction

Renal (26 decks)

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