Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

PSL301 > PSL301: Water 8 > Flashcards

PSL301: Water 8 Flashcards

Excretion of waste products; endocrine function

1
Q

UREMIA

A

a raised level in the blood of urea and other nitrogenous waste compounds that are normally eliminated by the kidneys
= advanced kidney failure

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

clinical symptoms of uremia

A
  • severe fatigue & weakness
  • poor appetite, nausea, vomiting
  • edema in feet, ankles
  • itchy skin
  • disturbed mental functions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Telltale biochemical marker of uremia

A

very high serum creatinine & urea levels (GFR < 10%)

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

What are the waste products excreted by urine?

A

mainly products of protein metabolism

  • urea
  • creatinine
  • uric acid (urate)

many other small molecules excreted in small amounts

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

most abundant waste in urine

A

urea

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

amount of waste found in urine depends on…

A

how much protein is eaten

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

each urea has __ nitrogens

A

2

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

Waste products in urine are readily ____ and minimally ___

A

filtered;

reabsorbed

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

___ is generated from AA breakdown

A

ammonia

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

ammonia is highly…

A

toxic

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

to combat toxic effects of ammonia, it is converted to ___ in the ____. This is then excreted in the urine.

A

urea;

liver

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

steps of urea generation from ammonia

A
  1. ammonia + CO2 -> carbamoyl phosphate
    • L-ornithene -> citrulline
    • L-aspartate -> arginosuccinate
  4. -> L-Fumarate + L-Arginine
  5. L-Arginine + H2O -> Urea + L-ornithene
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

enzyme: CO2 + NH3 -> carbamoyl phosphate

A

carbamoyl phosphate synthase

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

enzyme: carbamoyl phosphate + L-ornithene -> citrulline

A

ornithine carbamoyltransferase

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

enzyme: citrulline + L-aspartate -> arginosuccinate

A

arginosuccinate synthase

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

enzyme: arginosuccinate -> L-Fumarate + L-Arginine

A

argininosuccinate lysase

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

enzyme: L-Arginine + H2O -> Urea + L-ornithene

A

arginase

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

creatinine is generated from…

A

phosphocreatine -> creatine -> creatinine

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

PHOSPHOCREATINE

A

storage compound for energy in muscle

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

how many molecules of nitrogen does each creatinine molecule have?

A

2

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

enzyme: phosphocreatine -> creatine

A

creatine kinase

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

Uric acid is generated from…

A

nucleic acid break down

- uric acid = nitrogenous metabolite of purines

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

high concentrations of uric acid causes…

A

gout (type of arthritis)

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

gout typically occurs in the ___. It is caused by…

A

foot/ankles;

urate crystal deposition in joint fluids -> inflammation -> joint becomes swollen/tender/painful

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
enzyme: xanthine -> uric acid
xanthine oxidase
26
what is used to treat gout? why?
xathine oxidase inhibitors; | xathine oxidase is the enzyme that produces uric acid
27
some human studies suggest that a 60% GFR may be associated with...
increased risk of death from cardiovascular disease
28
___ and ___ are not toxic. The toxicity of low GFR is due to...
urea; creatinine; the small molecules that builds up in blood
29
endocrine functions of the kidney
1. renin 2. erythropoietin 3. vitamine D metabolism
30
renin is synthesized & secreted by...
cells of afferent arteriole
31
effect of renin on Na
increase Na reabsorption - ANG II (directly) - aldosterone (indirectly)
32
effect of renin on water
keeps water inside body - thirst - vasopressin
33
effect of renin on GFR
- constricts efferent arteriole to increase glomerular capillary pressure - increase GFR - balances out decreased GFR from hypotension
34
___ is synthesized by ___ at border of medulla and cortex where O levels are low
glycoprotein; | pericytes
35
where are pericytes located, and what are they used for?
located at border of kidney medulla & cortex, used to make glycoprotein
36
Why are pericytes located at the border of the medulla and cortex?
- O2 are low there - very sensitive to O levels - decreased O stimulates secretion of EPO
37
2 conditions which cause secretion of EPO
1. anemia | 2. hypoxemia
38
function of EPO
increase RBC production in bone marrow
39
EPO is a popular drug for...
long-distance athletes, where O2 is a limiting factor to success
40
function of vit D
increase absorption of dietary calcium from gut
41
how to activate vit D from diet or skin?
1) 25-hydroxylation in liver (can be stored here) | 2) 1-hydroxlation in kidney
42
what is the final active hormone of vit D?
1,25-(OH)2 vit D3 | = calcitriol
43
which vitamin D activation step is regulated? Which isn't?
regulated: 1-OHase in kidney unregulated: 25-OHase in liver
44
effect of PTH on calcium
Increase serum Ca - break down bone - reabsorption by kidney - increase rate at which vit D is converted to calcitriol (activity of 1-OHase)
45
what happens to vit D conversion if the kidney is damaged?
- no 1-OHase - low Ca absorption from gut - low serum Ca - stimulate high PTH
46
most common causes of uremia
1. diabetes (30-40%) | 2. high BP
47
uremia: why fatigue & weakness?
Low EPO secretion by kidneys - less RBC - reduced O carrying capacity of blood Waste products reduce muscle function
48
uremia: why hypertension?
kidney can't excrete Na+ as well (damage, reduced GFR) - Na+ retained in blood - pull water into blood as well
49
uremia: why edema?
kidney can't excrete Na+ as well (damage, reduced GFR) - Na+ in ECF - expanded ECF = edema
50
uremia: why high levels of urea, creatinine, urate?
low GFR can't process all the waste fast enough
51
what allows us to rule in chronic kidney disease / severe kidney failure?
high levels of urea & creatinine in serum | - if this is not present, we can rule out CKD
52
uremia: why hyperkalemia?
- impaired excretion of K by damaged kidney | - low GFR
53
How to treat hyperkalemia?
IV insulin | - moves K+ into cells
54
uremia: why metabolic acidosis?
impaired ammonium excretion by damaged kidney | - can't buffer H+
55
low GFR = metabolic ___
acidosis
56
uremia: why loss of appetite?
Low GFR => metabolic acidosis - continued food (protein) intake -> acid - acid binds to all available bicarb - kidney can't make ammonium to keep up with acid from diet - feels sick & unwell - negative effects on bone health
57
uremia: why low Ca, high PTH?
- kidney can't make calcitriol - reduced absorption from gut -> hypocalcemia - parathyroid responds to low Ca - lots of PTH - excess reabsorption of bone -> fragile
58
increased PTH secretion due to low low calcitriol is ____ hyperparathyroidism
secondary
59
untreated uremia leads to..
coma, death
60
treatment for uremia
- kidney dialysis | - kidney transplant
61
hypernatremia implies an decrease in ___ volume
intracellular
62
hyponatremia implies an increase in ____ volume
intracellular
63
urine concentration requires...
1. thick ascending limb function | 2. vasopressin action on collecting duct

PSL301 (29 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions