Brainscape's Knowledge GenomeTM

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


See full index

3 - Urinary > deck_1620063 > Flashcards

deck_1620063 Flashcards

1
Q

Outline the sequence of arteries leading into the kidney

A

• Renal Artery -> Segmental Arteries -> Interlobar Arteries -> Arcuate Arteries -> Interlobular Arteries -> Afferent Arterioles

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

Give one way in which the structure of the renal arteries increases pressure in the glomerulus

A

• The diameter of each afferent arteriole is slightly greater than the diameter of the associated efferent arteriole

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

What is the size limit and effective molecular radius for filtration?

A

• Size limit - 5,200 • Effective molecular radius - 1.48 nm

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

Why are proteins not usually filtered into the kidney?

A

• Size • Basement membrane and podocyte glycocalyx have many negatively charged glycoproteins which repel protein movement

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

How much blood is filtered by the renal artery at any one time?

A

• 20%

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

What happens to blood not filtered by the glomerulus?

A

• Exits via efferent arteriole

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

What are the two types of kidney nephron?

A

• Cortical • Juxtamedullary

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

Why is a juxtamedullary nephron named thus?

A

• Glomeruli located in cortex, but next to medullary bounds

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

Give two differences between cortical and juxtamedullary nephrons

A

• Juxtamedullary has longer loops of henle • Arrangement of peritubular capillaries around cortical nephrons messy • Structured and organised arrangement of capillaries in juxtamedullary nephron • Countercurrent flow in organised juxtamedullary nephron

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

How is filtration a selective process?

A

• Cells and large proteins do not get filtered through • Water, salts and small molecules pass through • Thanks to filtration mesh provided by podocytes

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

Where do the glomerula tufts always lie?

A

• In the cortex

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

Where does blood to be filtered arrive in the kidney?

A

• Glomerula tuft

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

What are the three layers in the filtration barrier?

A

• Capillary endothelium ○ Water, salts, glucose • Basement membrane ○ Acellular gelatinous layer of collagen/glycoprotein ○ Permeable to small proteins ○ -‘ve charge to repel protein movement • Podocyte layer ○ Pseudopods interdigitate and form filtration slits

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

It is more difficult for a positive protein to pass through membrane than a negative. Do you agree?

A

• No, negative repelled by -vely charged basement membrane

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

What happens if a clinical conditions results in negative proteins being stripped of their charge?

A

• They will be filtered and appear in the urine

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

Give conc of following in plasma and ultrafiltrate

A

• Glucose 100 • Na+ mmol/l 140 • Urea mg/dl 15 • Creatinine umol/l 60-120

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

Give three physical forces involved in plasma filtration

A

• Hydrostatic pressure in the capillary (regulated) (capillary -> tubule) • Hydrostatic pressure in bowman’s capsule (tubule -> capillary) • Osmotic (oncotic) pressure differences between the capillary and tubular (tubular -> Capillary)

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

What is the net filtration pressure in the glomerulosa?

A

• 10mmHg

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

What is the average hydrostatic pressure between capillaries and tubule?

A

• 50mmHG (about half of normal pressure)

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

What is the effect of charge on filtration?

A

• Neutral molecule - The bigger it is, the less likely to get through • Anions - Negative charge also repels, more difficult to get through • Cations - Positive charge allows slightly bigger molecules through

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

How is blood in afferent arteriole (going out) different to efferent (going in)?

A

• Oncotic (protein) pressure higher • Blood is more concentrated

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

Give one cause of proteinuria involving filtration forces

A

• In many disease processes the negative charge is lost on the filtration barrier, so proteins are more readily filtered

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

What is osmotic pressure?

A

• Force generated because of solute within solvent

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

What is oncotic pressure?

A

• Oncotic force in generated because of protein within solute

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

Why is absorption in kidney called reabsorption?

A

• Already been absorbed once by GI tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Give three mechanisms by which reabsorption occurs

A

• Osmosis • Diffusion • Active transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is tubular secretion?

A

• Substances secreted into renal tubular lumen from peritubular capillaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

By what mechanism are substances secreted into the tubular lumen?

A

• Active transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What two main types of substances are secreted into the tubular lumen?

A

• Those present in great excess • Natural poisons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What does secretion help to maintain?

A

• Blood pH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Give three examples of things actively secreted

A

• Protons • Potassium • Creatinine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are two methods of secretion into the PCT?

A

• Entry by passive carrier • Secretion into the lumen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is entry by passive carrier?

A

• Diffusion across basolateral membrane down conc grad created by Na+/K+ ATPase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

How does entry by active secretion differ to passive?

A

• Directly uses ATM and H+ gradient creat by Na+-H+ antiporter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Give two forms of reabsorption?

A

• Transcellular • Paracellular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

How easy is it for a cation to get through the filter compared to an anion?

A

• Positive charge of cation allows slighty bigger molecules through than anions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is reabsorption in PCT driven by?

A

• Sodium uptake

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

How is Na+ reabsorbed in tubular cells

A

• 3Na-2K-ATPase (Na into ECF, K+ into cell) • Na+ moves across the apical membrane from tubule lumen down its concentration gradient • Water follows into cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

In what way do solutes move in the PCT?

A

• Tubular lumen -> Intersticium -> Capillaries

40
Q

What are the three mechanisms via which tubular reabsorption occurs?

A

• Osmosis • Diffusion • Active transport

41
Q

What does iso-osmotic mean when applied to reabsorption?

A

• Osmosis does not take effect

42
Q

Where does unregulated absorption occur?

A

• Proximal convoluted tubule

43
Q

What is the method via which reabsorption occurs?

A

• Co-transport, following active transport

44
Q

What is the transport maximum?

A

• If plasma conc exceeds Tm, the rest spills over into urine

45
Q

What is the reabsorption path?

A

• Lumen -> Intersticium -> Peritubular capillaries

46
Q

How is reabsorption different from glomerula filtration?

A

• Occurs primarily through cells

47
Q

What 7 main substances are secreted into glomerula filtrate?

A

• Protons • Potassium • Ammonium ions • Creatinine • Urea • Some hormones • Some drugs

48
Q

Why do we need kidney secretion?

A

• Only 20% of plasma filtered in renal corpuscle each time

49
Q

From where does tubular secretion occur?

A

• From the epithelial cells that line the renal tubules and collecting duct into the glomerular filtrate

50
Q

How are organic cations secreted?

A

1) Entry by passive carrier into tubular lumen cell a. Positive cation from ECF moves into negative cell down electrical gradient. This is as a result of basolateral 3 Na+/2 K+ ATPase 2) Secretion into the lumen a. H-OC exchanger driven by H+ gradient created by the Na+-H+ antiporter b. Na+ into cell from lumen, H+ out cell into lumen c. Drives H+ into cell from lumen by creating conc grad d. Organic Cation out by active transporter

51
Q

Name three endogenous cations

A

• Dopamine • Adrenaline • Histamine

52
Q

Name three cationic drugs

A

• Morphine • Atropine • Sulfonamides

53
Q

Name three endogenous anions

A

• Urate • Bile salts • Fatty acids

54
Q

Name two anionic drugs

A

• Penicillin • Salicylate

55
Q

What is secondary active transport?

A

• Na+/K+ ATPase used to generate Na+ gradient

56
Q

Where is glucose reabsorbed in the nephron?

A

• Proximal convoluted tubule

57
Q

Through what transporter is glucose reabsorbed in the proximal convoluted tubule?

A

SGLUT

58
Q

What is SGLUT?

A

• 2 Na+ ions and 1 glucose • Glucose travels from lumen of tubule to the peritubular capillaries (moves into peritubular capillaries by facillitated diffussion

59
Q

What is Tm?

A

• Transport maximum from tubule to capillaries

60
Q

What is the renal threshold for glucose?

A

• 200mg/100ml

61
Q

What occurs if transport maximum for glucose exceeded?

A

• Rest of glucose spills over into urine • Causes polyuria

62
Q

Where does reabsorption of amino acids occur?

A

• Proximal convoluted tubule via Na+ co-transporters

63
Q

What is clearance?

A

• The volume of plasma from which any substance is completely removed by the kidney in a given amount of time (usually 1 minute)

64
Q

What is the clearance calculation?

A

• Clearance rate = Urine concentration of substance x Urine flow rate / Plasma concentration of the substance

65
Q

What is excretion rate?

A

• Amount in urine x Urine flow rate

66
Q

When are the inputs and outputs of the kidney?

A

• One input - Renal artery • Two outputs - Renal vein and Ureter

67
Q

What can we measure from the rate at which a substance appears in the urine, provided that that substance is completely cleared

A

• The GFR

68
Q

What is the Tm for glucose in males and females?

A

• Males - 375mg/min • Female 300 mg/min females

69
Q

What is glomerular filtration rate?

A

• The volume of plasma from which any substance (X) is completely removed by the kidney in a given amount of time

70
Q

What is GFR a measure of?

A

• Kidneys ability to filter a substance (overall function)

71
Q

What does a fall in GFR indicate?

A

• Kidney disease is progressing

72
Q

In order to measure GFR, what properties must a substance have?

A

• Must be freely filtered across the glomerulus • Must not be reabsorbed, secreted or metabolised • Must pass directly into the urine

73
Q

What is standard renal blood flow?

A

• 1.1l/min

74
Q

How can we find out renal plasma flow?

A

• Heamatocrit is the volume (%) of RBC in blood • Normally 45% • 0.55 x 1.1 (RBF) = 605ml - Plasma flow

75
Q

What is the filtration fraction of 605 ml plasma?

A

• 605ml x 0.2 = 125ml (20% blood processed per minute)

76
Q

What is GFR for males?

A

• 115-125 ml/min

77
Q

What is GFR in females?

A

• 90/100 mi/min

78
Q

Outline the GFR of inulin, glucose and para-aminohippurate

A

Inulin - 125ml/min - Not reabsorbed, not secretedGlucose - 0 - Completely reabsorbedPara-aminohippurate - 625 ml/min (Secreted!)

79
Q

Outline use of urea

A

• Used as an active osmol by the kidney

80
Q

What is filtration fraction?

A

• Proportion of a substance actually filtered • If renal plasma flow is 605ml/min, 20% of all plasma is filtered, 125ml filtered through into bowman’s space and 480ml passes through into peritubular capillaries • Filtration fraction = Glomerular filtration rate/Renal plasma flow • Filtration fraction about 20%

81
Q

What is autoregulation?

A

• Auto-regulatory mechanisms keep GFR within normal limits when arterial BP within physiological limits (80-120 average BP)

82
Q

What is myogenic autoregulation?

A

• Smooth muscles of afferent capillaries of glomerulus (those going in) contract to increase or decrease pressure

83
Q

What are the limits of myogenic autoregulation?

A

• Normal average blood pressure between 80-120 mmHG

84
Q

What is GFR?

A

• Glomerular filtration rate • A measure of the kidney’s ability to filter a substance

85
Q

Give two mechanisms of controlling blood flow to glomerulosa

A

a • Smooth muscle control in afferent and efferent arterioles • Tubular Glomerular feedback

86
Q

What happens to smooth muscle in afferent arterioles to glomerulosa if blood pressure drops?

A

Vasodilation

87
Q

What happens to smooth muscle in afferent arterioles to glomerulosa if blood pressure increases

A

• Vasoconstriction

88
Q

Outline tubular glomeruola feedback

A

• If arterial pressure too high • Increases glomerular capillary pressure • Increased glomerula filtration rate • More Na+ and Cl- in distal convoluted tubule • Macula densa cell in the JGA respond

89
Q

How do the macula densa cells in the JGA oppose high GFR

A

• Release adenosine (vasoconstrictor) or prostaglandin (Vasodilator)

90
Q

How much blood is received by the kidney each minute?

A

• 1.1 litres of blood

91
Q

What is general overflow aminoaciduria?

A

• All amino acids present in urine • Due to inadequate deamination in the liver, or increased GFR

92
Q

When is general overflow aminaciduria often seen?

A

• Early pregnancy

93
Q

What is specific overflow aminoaciduria?

A

• Only a specific AA is present in the urine. • This is usually do to a genetic inability to break down one AA • PKU • Homocysteinuria

94
Q

How can kidney stones develop as a result of renal aminoaciduria?

A

• Caused by dibasic acids, due to failure of transport system • Cystein abnormally insoluble, and is strongly associated with kidney stone formation • Cysteinuria associated with stone formationFUN FACT

95
Q

What is the difference between clearance rate and GFR?

A

GFR does not take into account secreted ions, but clearance rate does.

3 - Urinary (39 decks)

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