1.4 PHYSIOLOGY - Renal Flashcards Preview

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Flashcards in 1.4 PHYSIOLOGY - Renal Deck (108):
1

Waste product from proteins

Urea

2

Waste product from purines

Uric Acid

3

Waste product from muscles

Creatinine

4

Waste product from RBCs

Bilirubin

5

3 functions of the kidney

1. Excretion
2. Homeostasis
3. Secretion

6

Renal Circulation

Renal Artery --> Segmental Artery --> Interlobar Art. --> Arcuate Art --> Interlobular (Cortical radiate/Radial Art) --> Afferent Arteriole --> Glomerular Capillaries --> Efferent Arteriole --> Peritubular capillaries/Vasa recta --> Interlobular Vein --> Arcuate Vein --> Interlobar --> Segmental --> Renal Vein

7

Organs that produce glucose during starvation state

Liver and Kidney

8

Define Urine

an ultrafiltrate of blood

9

Location of the kidney

T12-L3

10

Weight of the kidney

150g

11

Basic parts of the kidney from lateral to medial

Capsule
Cortex
Medulla
Renal Papilla
Renal Calyces (Major and Minor)
Renal Pelvis

12

Only capillaries in the human body that leads to arterioles and not venules

Glomerular capillaries

13

2 types of nephrons

Cortical and JM nephrons

14

Capillaries of cortical nephrons

Peritubular capillaries

15

Capillaries of JM nephrons

Vasa recta (Peritubular capillary)

16

Capacity of the bladder

600ml

17

Volume when urge to urinate is felt

150ml (25% filled)

18

Reflex contraction of bladder

300ml

19

Stretch sensitive muscle of the bladder

Detrussor

20

Voluntary sphincter of the urethra

External urethral sphincter

21

Involuntary sphincter of the urethra

Internal urethral sphincter

22

Number of nephrons per kidney

1 Million

23

Nephrons cannot be regenerated. True or false?

True

24

2 Major parts of the nephron

1. Renal Corpuscle
2. Renal Tubular System

25

How many percent damage until compensatory hypertrophy of the kidneys?

75%

26

Differentiate cortical nephrons and JM nephrons based on:

Percentage
Location
Loops of Henle
Capillary Network

Percentage 75% Cortical - 25%JM
Location - Cortical, JM
Loops of Henle - Short LH - Long LH
Capillary Network - Peritubular capillaries - Vasa recta

27

3 barriers to filtration in the glomerulus

1. Endothelial Cell
2. Basement Membrane
3. Podocytes

28

Cells that secrete renin

JG Cells

29

Podocytes contain

1. Foot processes
2. Filtration Slits

30

Components of the basement membrane

Type IV Collagen
Lainin, Agrin, Perlecan, Fibronectin

31

Function of the Macula Densa

Monitor Na concentration and consequently blood pressure

32

Where are JG Cells and Macula Densa found?

Mnemonic: "JGA, MD"

JG - Afferent Arteriole
MD - Macula Densa Distal tubule

33

Workhorse of the nephron

PCT

34

Parts of the loop of henle

Descending limb
Thin ascending limb
Thick ascending limb

35

Parts of the distal tubule

Early and Late

36

Substances that are filtered only

Inulin and Creatinine

37

Substances that are filtered and partially reabsorbed

Many electrolytes

38

Substances that are filtered and completely reabsorbed

Glucose, Amino acids

39

Substances that are filtered and secreted

PAH, Organic acids and bases

40

Define filtration fraction

Fraction of renal plasma flow that is filtered

GFR/RPF

41

Normal filtration fraction

20%

42

Filterability of substances accdg to size

Water>Na, Glucose, Inulin>Myoglobin>Albumin

43

Filterability of substances accdg to charge

Positive Substances>Neutral>Negative Substances

44

Formula for GFR

GFR = Kf [(Pgc -Pbs) - (Ogc - Obs)]

45

Net filtration pressure

10 mmHg

46

Glomerular hydrostatic pressure

60mmhg

47

Bowman's capsule pressure

18 mmHg

48

glomerular oncotic pressure

32 mmHg

49

Describe the effect on GFR:

Afferent arteriole dilate

Increase

50

Describe the effect on GFR:

Aferrent arteriole constrict

Decrease

51

Describe the effect on GFR:

Eferrent arteriole dilate

Decrease

52

Describe the effect on GFR:

Eferrent arteriole constrict moderately

Increase

53

Describe the effect on GFR:

Eferrent arteriole constrict severely

Decrease

(Albumin collects in the glomerulus)

Gibbs-Donnan Effect

54

Describe the effect on GFR:

GC hydrostatic pressure increased

Increase

55

Describe the effect on GFR:

GC oncotic pressure increased

Decrease

56

Describe the effect on GFR:

BS hydrostatic pressure increased

Decrease

57

Describe the effect on GFR:

Kf increased

Increase

58

What are the causes of decreased Kf?

Renal diseases
DM
HTN

59

What is the cause of increased BS hydrostatic pressure?

Urinary tract obstruction

60

What are the causes of decreased GC hydrostatic pressure?

Hypotension (dec arterial pressure)
ACE-I (decreased eferrent arteriole constriction)
Sympathetic activity (inc aferrent arteriole constriction)

61

What are the hormones that will increase GFR?

EDRF, PGE2, PGI2, Bradykinin, Glucocorticoids, ANP, BNP

62

Which hormone will preserve GFR?

Angiotensin II
Preferentially constricts eferrent arteriole

Net effect is a decrease in GFR but only slightly hence preserves GFR

63

Blood flow is greater where?

Cortex or medulla?

Cortex

64

Local autoregulation of renal blood flow is exhibited at a BP range of?

75-160 mmHg

65

What do you call massive sympathetic stimulation that results in massive vasoconstriction of the kidneys?

CNS Ischemic Response

66

Other name for tubuloglomerular feedback

Macula densa feedback

67

Feedback mechanism that is responsible for autoregulation of GFR at a BP of 75-160 mmHg

Tubuloglomerular feedback

68

Action of adenosine in tubuloglomerular feedback

Vasoconstricts afferent arteriole

69

Action of nitric oxide in tubuloglomerular feedback

Vasodilates aferrent arteriole

70

Illustrate regulation of GFR in scenarios of High and low BP.

Pathways at Page 19 of handouts

71

Define glomerulotubular balance

Percentage of solute reabsorbed is held constant; Buffers effect of drastic GFR changes in urine output.

72

Define Renal threshold

Substances start to appear in the urine.
SOME nephrons exhibit saturation.

73

Define renal transport maximum.

ALL excess substances appear in the urine.
ALL nephrons exhibit saturation.

74

Some solutes do not have a transport maximum or threshold. What is this principle and how does this happen?

Gradient-Time transport

Rate of transport is dependent upon electrochemical gradient, membrane permeability and time.

Occurs for active and passive transport. The greater the concentration, the greater the flow rate and vice versa.

75

Tubule with the highest number of mitochondria

PCT

76

Lining of the PCT

Low columnar with extensive brush border (microvilli)

77

Percent of glucose and amino acids reabsorbed in the PCT.
Percent of NaCl and H20 rebasorbed in the PCT.

100%
66%

78

Which substances are rapidly filtered and almost none are reabsorbed in the PCT?

H+, Organic acids, bases, (bile salts, oxalate, urate and catecholamines) and drugs

79

Which is more hyperonic relative than the other? The fluid entering the PCT or the fluid leaving the PCT?

None. Isoosmotic.

80

Permeability of the loop of henle

"ASIN DING LIMB"

Descending limb
IMPERMEABLE to solutes
Permeable to water

Ascending limb
PERMEABLE to solutes
IMPERMEABLE to water

81

Histology of the thin and thick segments of the loop of henle

Thin segment - simple squamous with no brush border and few mitochondria

Thick segment - simple cuboidal

82

Percent of water reabsorbed in the loop of henle.

20%

83

Percent of Na, K, Cl reabsorbed in the loop of Henle

25%

84

Where is Mg2+ mainly reabsorbed?

Loop of henle

85

Hydrogen is secreted in the LH via the

Na-H countertransport

86

The distal tubule is divided into the

First part and second part

87

Histology of the distal tubule

Simple cuboidal without brush border

88

What is contained in the first part of the distal tubule?

JGA - macula densa, JG cells, lacis cells

89

Permeability of water in the first part of the distal tubule?

Relatively impermeable to water (similar to thick segment of the LH)

90

Structures contained in the second part of the distal tubule.

Principal cells
Intercalated cells

91

The second part of the distal tubule is responsive to which hormone?

Aldosterone

92

Absorption and secretion of principal and intercalated cells?

"PRINCIPE K"

Principal cells- secrete K, Absorb Na+ and H2O
Intercalate cells - secrete H+ , absorb K

93

Channels for absorption of Sodium in principal cells

ENaC channels

94

Secretion of H+ in intercalated cells is possible through the

H-ATPase pump
Na-H countertransport

95

Histology of collecting ducts

Cuboidal with well defined boundaries between cells

96

Site for regulation of final urine volume and concentration

COllecting ducts

97

Main hormone acting on the collecting ducts

Vasopressin

98

Collecting duct is permeable to ____ and secrets ____

Urea, H+ ions

99

What happens to tubular reabsorption and tubular secretion when peritubular capillary hydrostatic pressure increases?

Reabsorption decrease
Secretion increase

100

What happens to tubular reabsorption and tubular secretion when peritubular capillary oncotic pressure increases?

Reabsorption increase
Secretion decrease

101

Determine the site of action and effect of the hormone.

Aldosterone

DT and CD

Inc Na reabsorption
Inc H20 reabsorptiom
Inc K secretion
Inc H secretion

102

Determine the site of action and effect of the hormone.

ANP and BNP

DT and CD

Dec Na reabsorption

103

Determine the site of action and effect of the hormone.

Dopamine

PCT

Dec Na and water reabsorption

104

Determine the site of action and effect of the hormone.

Uroguanylin, Guanylin

PCT CD

Dec water and Na reabsorption

105

Determine the site of action and effect of the hormone.

PTH

PCT TAL LH

Dec phosphate reabsorption (phosphate trashing hormone)
Inc Ca reabsorption
Stimulates 1 alpha hydroxylase

106

What are the triggers of ADH secretion?

Inc plasma osmolarity
Dec blood pressure
Dec blood volume

107

What is the effect of alcohol on ADH secretion?

Dec ADH

108

Which hormone secreted by DT and CD acts similar to ANP?

urodilatin