renal Flashcards
(100 cards)
1
Q
what is the osmolarity of body fluids?
A
300mOsmol/L
2
Q
is the cell membrane permeable to sucrose?
A
no
permeable to urea
3
Q
what are the components of extracellular fluid?
A
plasma
interstitial fluid
lymph
transcellular fluid
4
Q
where does unregulated loss of fluid happen?
A
skin
lungs
5
Q
where does regulated loss of fluid occur?
A
sweat
faeces
urine
6
Q
is sodium concentration higher in extracellular or intracellular fluid?
A
Na is higher in the ECF
7
Q
is the concentration of Cl higher in extracellular or intracellular fluid?
A
Cl is higher in the ECF
8
Q
is the concentration of K higher in extracellular or intracellular fluid?
A
K is higher in the ICF
9
Q
is the concentration of HCO3 higher in the extracellular or intracellular fluid?
A
HCO3 is higher in the ECF
10
Q
what is mainly responsible for the osmolarity of ECF?
A
sodium
11
Q
what is mainly responsible for the osmolarity of the ICF?
A
potassium
12
Q
what % of cardiac output goes to the kidneys?
A
20-25%
13
Q
what processes occur in a nephron?
A
filtration
reabsorption
secretion
14
Q
which type of nephrons are in the long loop of henle?
A
juxtaglomerular
15
Q
which type of nephrons are in the short loop of henle?
A
cortical
16
Q
which nephrons produce concentrated urine?
A
juxtaglomerular nephrons
17
Q
which cells secrete renin in the juxtaglomerular apparatus?
A
granular cells
18
Q
is glomerular filtration a passive process?
A
yes
19
Q
is BP in the glomerular capillaries high or low?
A
high (55mm Hg)
20
Q
what is the normal value of net filtration pressure?
A
10 mm Hg favouring filtration
21
Q
what is the normal glomerular filtration rate?
A
125 ml/min
mainly determined by glomerular capillary BP
22
Q
what does a low GFR lead to?
A
decreased urine volume
23
Q
what is the extrinsic controller of GFR?
A
sympathetic control via baroreceptor
24
Q
what is the intrinsic control of GFR?
A
myogenic mechanism
tubuloglomerular feedback
25
what is the impact of kidney stones on GFR?
increased HPbc causing decreased GFR
26
does diarrhoea cause increased/decreased GFR?
decreased GFR
27
what can be used as a measure of GFR?
inulin
28
is glucose secreted?
no it is completely reabsorbed and should have 0 clearance
29
where abouts in the nephron does most reabsorption occur?
the whole length but mainly the proximal tubule
30
what is absorbed in the proximal tubule?
sugar
amino acid
phosphate
sulphate
lactate
31
what is secreted in the proximal tubule?
H+
neurotransmitter
uric acid
32
where is the Na-K pump found?
basolateral membrane
33
which ions are reabsorbed in the ascending loop of henle?
Na
Cl
34
does water reabsorption occur in the ascending loop of henle?
No
35
what is the most common cause of nephrotic syndrome in children?
minimal change disease
36
what are the possible causes of minimal change disease?
idiopathic
leukaemia
hodgkins lymphoma
virus
37
how does minimal change present?
facial/generalised oedema
heavy proteinuria
foot process fusion on EM
38
is minimal change nephritic or nephrotic?
nephrotic
39
how is minimal change treated?
steroids (prednisalone)
40
is FSGS nephrotic or nephritic?
nephrotic
41
what causes FSGS?
primary- autoimmune
secondary- HIV, obesity, sickle cell, PWID, reflux nephropathy
42
what are the features of FSGS under microscope?
weird mesangial cells
diffuse podocyte process fusion (primary)
podocyte process fusion limited to sclerotic areas (secondary)
43
where does necrosis occur in FSGS?
primary- everywhere
secondary- only in sclerotic areas
44
how is FSGS managed?
60% have long term remission with prolonged steroids
45
do you send urine cultures in old ladies with uncomplicated UTI?
not usually
except in people who have a reduced renal function
46
what are the features of an epidydimal cyst?
scrotal swelling and on palpitation is felt separate to testes
47
what is the most accurate way to measure GFR?
measuring inulin
48
how does hydrogen reach the tubular lumen?
hydrogen ATPase secretes it at the distal convoluted tubule
49
where do thiazides act?
in the Na/Cl channels in the distal convoluted tubule to prevent sodium reabsorption
50
where is the micturition centre located?
in the pons
51
what are the indications for dialysis?
acidosis
electrolyte
intoxication
overdose
uraemia
52
which condition can be caused after an ACEi is introduced to young females?
AKI- fibromuscular dysplasia
53
which pumps are at the apical membrane of the proximal tubule?
co transport= Na/glucose and Na/amino acids
counter transport= Na/H
54
which pumps are at the basolateral membrane of the proximal tubule?
diffusion (100% reabsorbed)= glucose and
amino acids
counter transport= Na/K
55
what increases water reabsorption in the distal tubule?
ADH (vasopressin)
56
what increases sodium reabsorption and H/K secretion from the distal tubule?
Aldosterone
57
what reduces sodium reabsorption in the distal tubule?
ANP
58
what increases calcium reabsorption and reduces phosphate reabsorption?
PTH
59
what effect does increased Na delivery to the kidney have on the macula densa?
macula densa constricts the afferent arteriole and increases renal blood flow
60
what affect does kidney have on vit D production
activates calcidiol and converts it to calcitriol
61
what is used to measure effective renal plasma flow?
paraamino hippurate
62
what filters by negative charge?
the glomerular basement membrane
63
why is GFR slightly over estimated?
because creatinine is slightly secreted in the kidney
64
do prostaglandins dilate the efferent arteriole?
no
they dilate the afferent arteriole which increases GFR
65
what is a sign of ESKD?
decreased calcium and anaemia
66
what is the affect of ANP on the arterioles?
vasodilation of the afferent arterioles and vasoconstriction of the efferent arterioles
67
does metabolic alkalosis result in increased K secretion?
yes
68
what does nephrotic syndrome result in?
reduction of capillary colloid pressure and oedema
69
where is the majority of filtered potassium absorbed?
the proximal convoluted tubules
70
what is the consequence of an increase in hydrostatic pressure in bowmans capsule?
reduced GFR
71
how does ADH allow for water reabsorption?
via the insertion of aquaporin II channels on the luminal membrane
72
where does AHD act?
the collecting ducts
73
what kind of vasculitis is HSP?
small vessel IgA mediated vasculitis
74
how does CKD lead to anaemia?
due to reduced levels of erythropoietin
75
what bacteria is most likely to cause peritonitis in peritoneal dialysis?
staph epidermis
coag negative
76
can Wegener's granulomatosis (GPA) cause rapidly progressive glomerulonephritis?
yes
77
how does amyloidosis present?
middle aged
muscle weakness
breathlessness
reduced kidney function
78
what is the first line investigation in peritonitis?
pd fluid microscopy with cell count, culture and sensitivity
79
what does foot processes indicate?
minimal change
80
what can interact with immunosuppressants and cause nephrotoxicity?
trimethoprim
81
Which nephron structure is especially important in the kidney’s ability to produce urine of varying concentration?
loop of henle
82
what is the glomerular filtration rate?
is a protein-free plasma and is formed as a result of passive forces acting across the glomerular membrane
83
what has a large impact on the reduction of net filtration pressure?
a large increase in blood colloid osmotic pressure
84
what is the renal threshhold?
plasma concentration of a particular substance at which its Tm is reached and the substance first appears in the urine
85
why is angiotensin I formed?
as a result of activation of angiotensinogen by renin, and is transformed into angiotensin II as a result of converting enzyme action in the lungs
86
where does water reabsorption occur?
to the greatest extent in the proximal convoluted tubule and is under vasopressin control in the distal and collecting tubules
87
what is plasma clearance?
volume of plasma that is completely cleared of a substance by the kidneys in one minute of time
88
what does vasopressin do?
activates the cyclic AMP second-messenger system within the tubular cells
89
which segment of the nephron is not permeable to H2O even in the presence of vasopressin?
ascending limb of the loop of henle
90
how does urine move from the kidneys to the urinary bladder?
peristaltic contraction of the smooth muscle of the ureters
91
what structures do somatic motor muscles supply?
the distal urethra, external urethral sphincter and levator ani
92
what affect do 5-alpha reductase inhibitors have on the prostate?
shrinks it
93
what is the blood supply to the scrotum?
Internal pudendal and branches from external iliac artery
94
what is used to visualise kidney stones?
non contrast CT
95
what causes bleeding at the start of urination?
prostate or urethra
96
what causes bleeding at the end of urination?
bladder neck
97
how much creatinine is reabsorbed by the kidneys?
0%
98
which abx are used in pregnant women with a UTI?
nitrofuratoin= 1st and 2nd trimester
trimethoprim=3rd semester
99
what is the first line imaging in suspected renal malignancy?
USS
100
what are the features of parasympathetic nerve outflow?
craniocaudal and includes CN III, VII, IX, X. Also S2, 3, 4
