8 votes

Why is ammonia converted to urea rather than secreted in the urine?

The comment of the poster to my request for clarification cites “The formation of ammonia itself requires… large quantities of water to dilute it out of a biological system” I conclude that he assumes ...
David's user avatar
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6 votes
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How do birds concentrate their urine?

First off, I think it's helpful to go backward a step and figure out why an animal might make and concentrate urine in the first place. There's no usefulness in itself to having concentrated urine, it'...
Bryan Krause's user avatar
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6 votes

What Produces the Postive Potenial in the lumen of the thick ascending loop of Henle?

Don't pay attention to the stoichiometry of the pumps, that will only fool you! The charge is due to passive movement through open channels. This is shown as the "yellow tubes" with dotted ...
Bryan Krause's user avatar
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6 votes
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Why is urea not converted to ammonia in the body?

The answer to this question is quite simply this: The activation energy for the uncatalysed reaction is such that the amount of decomposition of urea in aqueous solution at blood temperature and ...
David's user avatar
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5 votes

Why is urea not converted to ammonia in the body?

[Partial answer] [OP claim:] Urea in water can decompose into ammonia which is toxic. Probably not as easily as you think. If Wikipedia is correct: Urea alone is very stable due to the ...
the gods from engineering's user avatar
4 votes
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Excess protein consumption effect on kidney

Short answer The ammonia resultant from the protein metabolism is toxic to the body and specially kidney. (William V. et al.) Long answer Protein is a poly-peptide composed by amino acids. Each ...
Kiny's user avatar
  • 306
4 votes

Acidity and Alkalinity of Foods

Extracellular acid base homeostasis in human physiology is maintained primarily by the bicarbonate buffer, as regulated by both the kidneys and the lungs (and to a certain extent, the intracellular ...
De Novo's user avatar
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3 votes
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How might IV-saline cause kidney damage that seems to be less likely with "balanced fluids" IVs instead?

Short answer There is not likely to be a single mechanism involved, but the study authors suggest that high chloride is the main issue; they refer to previous work showing a whole variety of issues ...
Bryan Krause's user avatar
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2 votes

Is Valerian extract a diuretic or an antidiuretic?

There is one study that I can find that has been cited in the medical literature that examines individuals taking valerian extract for generalized anxiety disorder. In this paper, there do not appear ...
Vance L Albaugh's user avatar
2 votes
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Diabetes Mellitus and renal failure?

I am putting here the main points from the link given by @WYSIWYG (i.e. this): High glucose levels reduce the levels of the powerful vasodilator nitric oxide in blood vessels, a shortfall that ...
another 'Homo sapien''s user avatar
2 votes

Function of human kidneys

There are metanephric diseases, which refer to the location of pathologic tissue relative to the main kidney mass, but unless someone with more expertise wants to weigh in, I don't think that kidneys ...
Forest's user avatar
  • 1,879
2 votes

How is the renal osmotic gradient maintained even though the blood osmolarity changes?

The water doesn't get drained. As blood flows down a vas rectum, in any given section of the arteriole the tonicity is slightly higher outside the arteriole vs inside the arteriole. This results in ...
rotaredom's user avatar
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2 votes

Animal species anatomy

No. Lungs are a feature of tetrapods (land vertebrates) and some lungfish. Many fish have swim bladders, which are thought to be homologous to lungs (they evolved from the same ancestral structure) ...
Oosaka's user avatar
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2 votes

For how long can a person drink sea water?

After drinking 1 liter of seawater with 3.5% salt your kidneys need to excrete at least 1.5 liters of urine in order to maintain normal blood sodium levels, which leaves you with 0.5 liter of negative ...
Jan's user avatar
  • 8,079
1 vote

How do birds concentrate their urine?

Unlike mammals, birds excretory matter is not liquid but a semi-solid matter which is concentrated uric acid (this is not to be confused with feces which is the dark solid matter). Their urinary ...
Nilay Ghosh's user avatar
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1 vote

What is meant by re-absorption?

In the glomerulus of the nephron we have filtration occuring. The subsequent formation of an ultra-filtrate travels down the tubulus from Bowmans space; during this journey, the filtrate will be ...
HypoChloremic's user avatar
1 vote

Is Valerian extract a diuretic or an antidiuretic?

The Natural Medicines Database monograph for Valerian includes a pooled adverse effects analysis of more than 20 clinical trials with Valerian for various indications. No diuretic effects were ...
Polymania's user avatar
  • 326
1 vote

How do organophosphates affect kidney function?

One article suggests that NTEs in kidneys are important for regulating NaCl concentrations, whereby if increasing concentrations of NaCl are sensed in inner medullary collecting duct cells ...
The Contextual Path's user avatar
1 vote
Accepted

Why does glomerulus don't allow white blood cells to leave?

Red blood cells, White blood cells, platelets and proteins with large molecular weight cannot pass through the podocyte and fenestrations in glomerular capillary, but small molecules like water, salts ...
Twinkle Sheen's user avatar
1 vote

Creatinine excretion

Creatinine is formed irreversibly and non-enzymically from creatine and phosphocreatinine and is usually assumed to be metabolically inert in humans (Wyss & Rima Kaddurah-Daouk, 2000, Creatine and ...
user338907's user avatar
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1 vote

Polar renal scarring in pyelonephritis?

It's more an issue of the extent of reflux than anything else. If you look at the data on scarring, you'll see that grade III and IV VUR present with lateral scarring as well. So, any pyelonephritis ...
De Novo's user avatar
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1 vote

Do fruit juices have a diuretic effect & what governs this?

In short: Drinking fruit juice by a healthy person with a normal kidney function do not likely have any significant diuretic effect. Even if you drink, let's say, 2 liters of 10% fruit juice within ...
Jan's user avatar
  • 8,079
1 vote
Accepted

Is the glomerular filtration rate, per kidney or for both?

The definition of GFR given in Wikipedia - Glomerular filtration rate (GFR) is the volume of fluid filtered from the renal (kidney) glomerular capillaries into the Bowman's capsule per unit time. ...
Polisetty's user avatar
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1 vote

Can polystyrene sulfonate bind calcium or sodium in the gut? How?

Are you talking about Sodium Polystyrene Sulphonate (a.k.a SPS)? If yes, then ... Quoting from Chaitman, Dixit and Bridgeman (2016) Synthetic cation-exchange resins are insoluble polymers ...
Abell's user avatar
  • 11
1 vote

How does the counter-current multiplier work in the nephrons?

Countercurrent multiplication What is flowing in the opposite direction to the glomerular filtrate for it to be called "counter-current"? The filtrate is moving in the opposite direction ...
De Novo's user avatar
  • 8,791
1 vote

Why are ammonium ions reabsorbed in the thick ascending limb during acid secretion?

Why reabsorb $NH_4^+$ in the thick ascending limb if you're just going secrete it in the collecting duct This is an excellent question. When you find an odd, seemingly inefficient aspect of ...
De Novo's user avatar
  • 8,791
1 vote

Why are ammonium ions reabsorbed in the thick ascending limb during acid secretion?

Isn't it all to do with the reabsorption of water, i.e. everything gets flushed out in the Bowman's capsule and then some stuff is reabsorbed to lower the water potential of blood, so water is ...
Oliver Houston's user avatar
1 vote
Accepted

Find how much times blood is filtered in the kidney?

I'll try to dissect your teachers answer for you: 1/12*60=5 liter blood no explanation required here 0.55*5=2.75 liter plasma of blood. only the plasma is filtered in the kidney (the 45% cell ...
Thawn's user avatar
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