Brainscape's Knowledge GenomeTM

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


See full index

MB2: Renal > Physiology > Flashcards

Physiology Flashcards

1
Q

what is osmolarity

A

concentration of osmotically active particles in solution

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

calculation of osmolarity?

A

multiply molar concn by number of osmotically active particles present

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

are osmolarity and osmolality the same

A

if in weak salt solutions and body fluid compartments yes

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

what is the osmolarity of typical body fluid

A

~300mosmol/l

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

what is tonicity

A

is the effect a solution has on cell volume

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

what is an isotonic solution

A

no change in cell volume

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

what is a hypertonic solution

A

decrease in cell volume

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

what is a hypotonic solution

A

increase in cell volume

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

total body water in L for 70kg male

A

42L

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

intracellular fluid makes up __% of TBW

A

66%

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

ECF makes up __% of TBW

A

33%

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

what part of the body make up ECF

A

plasma
interstitial fluid
transcellular fluid
lymph

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

tracer for TBW

A

triated water

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

tracer for ECF

A

inulin

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

tracer for plasma

A

radiolabelled albumin

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

how do tracers measure volume of distribution

A

add known quantity of tracer to the body

measure equilibrium volume in the body

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

what are insensible water losses and what are they

A

losses of water in the body with no control
skin diffusion
lung

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

what are sensible water losses and what are they

A

sweat
faeces
urine
losses with physiological control

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

concentration of Na in ICF/ECF

A

10mM ICF

140mM ECF

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

concentration of K in ICF/ECF

A

140mM ICF

4.5mM ECF

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

concentration of bicarb in ICF/ECF

A

10mM ICF

28mM ECF

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

concentration of Cl in ICF/ECF

A

7mM ICF

115mM ECF

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

what electrolytes make up the majority in ECF

A

Na
Bicarb
Cl

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

what electrolytes make up the majority in skeletal muscle ICF

A

K

Mg

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

describe the fluid shift if there is an increase osmolarity of ECF

A

ECF becomes hypertonic and so there is fluid shift to ECF to increase ECF volume
cell volume decreases

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

describe the fluid shift id there is a decrease osmolarity of ECF

A

ECF becomes hypotonic and so there is fluid shift to ICF to increase cell volume and maintenance of ECF balance

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

True/false - gain or loss of isotonic fluid causes fluid shift

A

false - but kidneys do alter the composition and volume of ECF

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

what electrolytes are the main components of osmolarity of ECF/ICF

A

Na/K

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

Na is mostly intra/extracellular

A

extracellular

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

K is mostly intra/extracellular

A

intracellular - small ECF changes have devastating effects on skeletal muscle and cardiac contractility

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

functions of the kidney

A 
water/salt balance 
maintains plasma volume and osmolarity 
acid-base balance 
excrete waste 
excrete exogenous compounds 
secrete renin
secrete erythropoietin 
converts Vit D to active
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

3 functional mechanisms of the kidney

A

filtration
secretion
reabsorption

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

Components of the glomerulus

A 
glomerulus 
bowmans capsule 
proximal convoluted tubule 
loop of henle 
distal convoluted tubule 
collecting duct 
juxtaglomerular apparatus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

types of nephron and the key differences

A

juxtamedullar/cortical
JM have a longer loop of henle and have a vasa recta instead of peritubular capillary
produce more concentrated urine

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

what makes up the glomerular capillary

A

endothelial cells
basal lamina
podocytes

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

describe blood flow to the glomerus

A

enters by afferent arteriole and exits by efferent arteriole

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

where is the juxtaglomerular apparatus located anf what two sections does it encompass

A

distal tubule comes in between afferent/efferent arteriole
granular cells
macula densa

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

function of granular cells

A

secrete renin

sit between afferent/efferent arterioles and distal tubule

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

function of macula densa

A

detect salt between tubular fluid as it passes through the distal tubule
can signal through chemical messengers to influence afferent arteriole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

what % of blood is filtered by the glomerulus

A

20%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

calculation of rate of filtration

A

[X]plasma x GFR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

calculastion of rate of excretion

A

[X]urine x Vu (volume urine produced)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

calculating rate of reabsorption

A

rate of filtration-rate of excretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

calculating rate of secretion

A

rate of excretion-rate of filtration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

if rate filtratrion>rate of excretion then reabsorption/secretion has taken place

A

reabsorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

if rate excretion>rate of filtration then reabsorption/secretion has taken place

A

secretion

47
Q

true/false - the diameter of the efferent arteriole is greater than that of the afferent arteriole

A

false - the afferent arteriole is bigger to accomodate for GFR

48
Q

what does the glomerular capillary endothelium function to do?

A

filters red blood cells to prevent entry to bowmans capsule

49
Q

what does the basal lamina of the glomerular capillary do

A

acts as a barrier to plasma proteins

50
Q

what do the slit processes of podocytes function to do within the glomerular capillary

A

barrier to plasma proteins

51
Q

value of glomerular capillary blood pressure

A

55mmHg

52
Q

value of bowmans capsule hydrostatic pressure

A

15mmHg

53
Q

value of capillary oncotic pressure

A

30mmHg

54
Q

value of bowmans capsule oncotic pressure

A

0mmHg

55
Q

calculation of net filtration pressure

A

forces favouring filtration-forces opposing filtration

56
Q

rough net filtration pressure of the glomerular capillary

A

10mmHg

57
Q

calculation of GFR

A

Kf (filtration coefficient) x net filtration pressure

58
Q

what is the rough normal GFR

A

125ml/min

59
Q

true/false - the filtration coefficient is the main determinant of GFR

A

false - glomerular capillary blood pressure is - which increases net filtration rate

60
Q

true/false - increase in blood pressure increases GFR

A

true - but up to a point as the kidneys are autoregulated

61
Q

describe the control of GFR in decreased blood pressure

A

detected by aortic/carotid baroreceptors causing increased sympathetic output and SVR
this constricts afferent arterioles to reduce GFR and urine volume

62
Q

what is the myogenic mechanism of GFR control

A

vascular smooth muscle stretch causes constriction of the afferent arteriole

63
Q

what is the tubuloglmerular feedback mechanism and how does it act to control GFR

A

involves juxtaglomerular apparatus
increasing GFR increases Na flow to macula densa, causing release of vasoactive substances to vasoconstrict the affernt arteriole

64
Q

describe the effects of a kidney stone on GFR

A

leads to back pressure onto bowmans capsule and opposes filtration, leading to reduced GFR

65
Q

describe the effects of diarrhoea on GFR

A

loss of plasma fluid leads to plasma protein concentration, and increase in capillary oncotic pressure. this leads to reduced GFR

66
Q

describe the effect of significant burns on GFR

A

loss of plasma proteins in the blood, reducing capillary oncotic pressure and subsequently increasing GFR

67
Q

describe the effect of a change in Kf on GFR

A

increase in Kf increases GFR and decrease decreases it

this is a measure of the membranes permeability

68
Q

what is plasma clearance

A

how effectively the kidneys clean the blood

69
Q

calcuation for plasma clearance

A

[X]urine x [V]urine/[X]plasma

70
Q

describe how inulin can be used to determine plasma clearance and its unique characteristic

A

it is a non toxic exogenous chemical and is fully filtered at glomerulus with no secretion/reabsorption
this means it can be used to determine GFR using clearance calulation

71
Q

describe the clearance of creatinine and its uses over inulin

A

it is endogenous and so doesnt need constant infusion, less expensive to measure
it is not as effective as inulin as it doesn undergo minor secretion in the tubules, but can be used to measure GFR

72
Q

what is the clearance value of glucose and explain why

A

clearance =0

it is filtered by the glomerulus but undergoes full reabsorption

73
Q

what is the clearance of urea relative to GFR and explain why

A

clearance

74
Q

what is the clearance of H+ ions relative to GFR and explain why

A

clearance>GFR

it undergoes full filtration and secretion into the tubules by the peritubular capillaries

75
Q

if clearance >GFR then substance is _____

A

secreted

76
Q

if clearance is

A

reabsorbed

77
Q

what is the function of pan-amino-hippuric acid

A

used to measure renal plasma flow, it is not fully filtered by glomerulus but the rest is secreted, therefore determines renal plasma flow

78
Q

healthy level of renal plasma flow?

A

650ml/min

79
Q

what is filtration fraction, how is it calculated and what is it roughly equal to

A

fraction of plasma flowing through glomerulus that is filtered into the tubules
GFR/RPF
20%

80
Q

calculation of renal blood flow and rough estimate

A

RPF x 1/1-HCT

1200ml/min

81
Q

fluid reabsorbed in the proximal tubule is hypo/iso/hyper osmotic?

A

iso-osmotic

82
Q

what is reabsorbed in the prox tubule

A 
sugars 
amino acids 
Na 
PO4
Sulphate 
lactate
83
Q

what is secreted into the prox tubule

A 
neurotransmitters 
bile pigments 
H 
drugs 
toxins
84
Q

how much salt and water is roughly absorbed in the pro tubule

A

2/3

85
Q

how is Na reabsorbed in the prox tubule

A

Na/K ATPase at basolateral membrane
Na/glucose, Na/amino acid co-transport and Na/H countertransport
reabsorbed transcellular
this allows for passive H2O and Cl to follow
this passes into vasa recta by oncotic drag

86
Q

what is oncotic drag in respect to the vasa recta

A

there isnt much fluid in the vasa recta, so it soaks it up from interstitial fluid

87
Q

how is glucose reabsorbed

A

Na/K ATPase at basolateral membrane
Na/Glucose co-transporter, enters cell transcellular and exits basolateral membrane by facilitated diffusion into vasa recta

88
Q

what is Tm

A

transport maximum
there is a threshold to secretion/reabsorption due to channel saturation
excess remains wither in blood or remains in urine as it cannot pass quick enough

89
Q

describe what is reabsorbed/secreted in the ascending limb of the loop of henle

A

impermeable to water
urea secreted
NaCl exits by the triple co-transporter

90
Q

describe what is reabsorbed/secreted in the descending limb of the loop of henle

A

cannot reabsorb salt but water exits

91
Q

describe the action of the loop of henle in countercurrent multiplication and concentrating urine

A

solute is removed from ascending limb and water cannot follow
tubular fluid becomes diluted to raise interstitial osmolarity
water leaves descending limb by osmosis, concentrating fluid in descending limb and creating a cycle

92
Q

besides the action of NaCl in countercurrent multiplication, what else contributes?

A

urea, reabsorbed from collecting duct and secreted back into ascending loop of henle

93
Q

describe the action of the triple co-transporter

A

Na/K/Cl are pumped into cell from tubular fluid
potassium channels are present to pump potassium back out to the ascending limb
Na/K ATPase on basolateral membrane
water isnt reabsorbed

94
Q

what drug blocks the triple co-transporter

A

loop diuretics

95
Q

describe the action of the vasa recta as a countercurrent exchanger

A

capillary blood equilibrates with interstitial fluid on descent into the renal medulla
blood osmolarity raises and falls with the loop of henle respectively
this is to prevent blood flow washing away NaCl and water
as a result, there is no net gain of water/solute in the vasa recta

96
Q

fluid in the distal tubule is hyper/hypo-osmotic

A

hypo

97
Q

what is reabsorbed in the early distal tubule?

A

Na/Cl by triple co-transport

98
Q

what is reabsorbed in the late distal tubule

A

calcium
potassium
sodium

99
Q

what is secreted in the late distal tubule

A

potassium, when aldosterone present

H ions

100
Q

what is central DI

A

failure to produce ADH

101
Q

what is nephrogenic DI

A

failure to respond to ADH

102
Q

describe the secretion of ADH from the posterior pituitary

A

made by nerve cells in supraoptic and paraventricular cells
transport down nerves to terminals where it is stored in granules
released into blood when AP down nerves leads to Ca release

103
Q

describe the effect of ADH on urine concentration and the late distal tubule

A

binds to ATII receptor on basolateral membrane to increase cAMP and cause aquaporins to fuse with apical membrane
due to high interstitial osmolarity difference water flows along osmotic gradient into the interstitium

104
Q

what inhibits ADH?

A

alcohol and upper GI stretch receptors

105
Q

what stimulates ADH

A

nicotine

106
Q

besides the effect of ADH on the distal tubule and collecting duct, what else does it do

A

stimulates thirst

107
Q

describe the action of aldosterone on the nephron

A

stimulates Na reabsorption and K secretion
increase in plasma K promotes aldosterone OR indirectly through juxtaglomerular apparatus
increases action of Na/K ATPase at basolateral membrane and leads to futher Na reabsorption in Na channels
passive Cl diffusion

108
Q

describe the RAA system

A

decrease in NaCl, ECF, BP activate renin to cleave angiotensinogen to AT I
converted to AT II by ACE inb lungs
stimulates aldosterone release to increase Na reabsorption, Cl and hence H2O
AT II releases ADH, increase thirst and promote afferent vasodilation

109
Q

describe how congestive heart failure leads to fluid and salt retention

A

reduced CO leads to reduced BP and activates RAAS, but increases preload so worsens heart failure, this is a cycle

110
Q

describe the release of renin

A

macula densa cells sense reduced NaCl so promote aldosterone release
ie reduced GFR stimulates renin
increased sympathetic activity can cause renin release due to low BP

111
Q

describe the secretion of ANP and its action

A

promotes Na excretion and diuresis to reduce plasma volume
inhibits Na reabsorption and RAAS
less stimulation of SNS so less CO and BP
less tonic stimulation of afferent arteriole so increased GFR to increase Na and H2O filtration

112
Q

what type of contractions push urine through the ureter

A

peristaltic

113
Q

what overrides involuntary bladder emptying by external/internal urethral sphincters

A

tightening of external sphincter and pelvis diaphragm by voluntary control

MB2: Renal (11 decks)

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