renal - lecture 6

Question 1

what is alkalosis

Answer 1

low [h+] = high ph
resp alkalosis results from altered respiration
metabolic alkalosis results from other causes

Question 2

what is acidosis

Answer 2

high [h+] = low ph
resp acidosis results from altered respiration
metabolic acidosis results from other causes

Question 3

name 3 responses to acidosis

Answer 3

1 - sufficient h+ are secreted to reabs all filtered bicarb
2 - still more h+ secreted and contributes to new bicarb to the plasma as h+ excreted are bound to non bicarb buffer like hpo4 2-
3 - tubular glutamine metabolism and ammonium excretion are enhanced = contributes to new bicarb to plasma
all 3 active to try to help

Question 4

what is net result when acidosis

Answer 4

more new hco3 - than usualy added to plasma = compensates for acidosis
urine highly acidic
lowest ph = 4.4

Question 5

name 3 responses to alkalosis

Answer 5

1 - rate of h+ secretion inadequate to reabs all filtered bicarb = so lots of bicarb excreted in purine - not complete reabs anymore
2 - little/no h+ secretion on nonbicarb buffers
3 -tubular glutamate metabolism and ammonium excretion decreased so that little or no new bicarb contributed to plasma from this source

Question 6

describe net result when alkalosis

Answer 6

plasma bicarb will decrease = compensates for alkalosis
urine high alkaline ph >7.4

Question 7

describe classification of acidosis and alkalosis

Answer 7

resp = primary abnormality =co2
metabolic = primary abnormality hco3-
primary and compensatory = same direction

Question 8

what happens when resp acidosis

Answer 8

Pco2 = increase co2 so reaction shifts right and h
+ increases
H+ = increase
HCO3 - = since [bicarb]/[co2] = then bicarb must go up to compensate

Question 9

what happens when resp alkalosis

Answer 9

Pco2 = decrease
H+ = decrease
HCO3 - = decrease

Question 10

what happens when metabolic acidosis

Answer 10

HCO3 - = decrease
H+ = increases
Pco2 = decreases

Question 11

what happens when metabolic alkalosis

Answer 11

HCO3 - = increases
H+ = decreases
Pco2 = increases

Question 12

describe clinical ex of resp acidosis

Answer 12

resp failure with co2 retention
compensates = increase bicarb

Question 13

describe clinical ex of resp alkalosis

Answer 13

hyperventilation eg high altitudes
also pregnant women
bicarb compensates by decreasing

Question 13

what are diuretics

Answer 13

drugs used to clinically increase vol of urine excreted

Question 13

describe clinical ex of metabolic acidosis

Answer 13

diarrhea = loss of bicarb in poop
renal failure = accumulation of inorganic acids
so body naturally hyperventilates so co2 goes down

Question 13

describe clinical ex of metabolic alkalosis

Answer 13

less common
vomiting = loss of hydroen ion in vomit
hyperaldosteronism= primary aldol= increased h
+ secretion in dct and ccd, loss of h+
so tries to retain more co2 to compensate

Question 13

what do diuretics act on

Answer 13

tubules to inhibit reabs to sodium along with chloride and or bicarbonate
Results in increased excretion of these ions
water excretion increased too
sodium and water excretion in urine

Question 13

describe loop diuretics

Answer 13

acts on thick ascending limb
most common
inhibits cotransport of sodium, chloride and potassium = Na -K -2Cl cotransporter
furosemide
stops na reabs at tal

Question 14

describe potassium sparing diuretics

Answer 14

other diuretics lead to hypokalemia
inhibit na reabs in ccd and also inhibits k secretion here
unlike other diuretics, plasma conc of k doesnt dcrease
either block action of aldosterone or block aldosterone regulated epithelium na channel in ccd
amiloride, spironolactone

Question 15

describe action of potassium sparing diuretics - figure

Answer 15

block aldosterone and k secretion
spironolactone blocks aldosterone = which controls channels and nakatpase
amiloride = blocks sodium channel channel similar to blocking aldosterone
= k+ secretion coupled

Question 16

what is clinical use of diuretics

Answer 16

renal retention of salt and water = abnormal expansion of ecf = edema

Question 17

what is clinical use of diuretics ex 1 and 2

Answer 17

congestive heart failure = cardiac failure leading to lowered co, kidney sense by baroreceptors and reabs salt and water back = edema and wet lungs = bad
hypertension = in some patients with hypertension, renal retention of salt and water contribure to high bp, use less powerful diuretics

Question 18

name many common features of kidney disease or failure

Answer 18

proteinuria = protein in urine
accumulation of waste products in blood = urea, creatinine, phosphate, sulfate
high k conc in blood = hyperkalemia
metabolic acidosis
anemia = decreased secretion of epo - so no good rbcs but now = recombinant epo can be administered
decreased secretion of 1,25-hydroxylated vit d = leads to hypocalcemia = final hydroxylation in kidneys

Question 19

when do kidneys need replacement therapies

Answer 19

when more than 90% of nephrons stop working= cannot sustain life
one must have renal replacement therapies

Question 20

name 3 renal replacement therapies

Answer 20

1. Hemodialysis
2. Peritoneal dialysis
3. Kidney transplantation

Question 21

describe hemodialysis - gen

Answer 21

surgically enlarged veins = blood flows to hemodialyzer and gets filtered then returned to body via vein = 3-4 hrs per day a few times a week= need it to live

Question 22

describe hemodialysis - specifics

Answer 22

arterial blood from patient –> blood pump 350-400ml/min –> anticoagulants added –> dialyzer= strands of tubings removes waste products from blood and gets rid of extra water , fresh dialysis fluid (concentrate and purified water) added in –> air trap an air detector –> venous blood returned to patient

Question 23

describe peritoneal dialysis

Answer 23

lining of patients own abdominal cavity - peritoneuem used as dialysis membrane
fluid injected into cavity via tube inserted through abdominal wall
solutes diffused into fluid from persons blood
fluid exchanged several times per day
cycler automatically does it over night = good at home
brain bad = after a few hours = many times a day
do not have to stay attached

Question 24

describe kidney transplantation

Answer 24

best replacement
either from deceased person (cadaveric transplant) or from living related/unrelated donor - altruistic donor
anti rejection treatments have improved lots in recent years
organ shortage a problem
donors can function quite normally with one kidney
best = if twin donates kidney since no chance of rejection