Skip to main content
99 votes

Can a person survive on blood in place of water?

Blood is not a good source of water. 1 liter of blood contains about 800 mL of water, 170 grams of protein and 2 grams of sodium (calculated from the composition of lamb blood). When metabolized, 170 ...
Jan's user avatar
  • 8,079
18 votes

Can a person survive on blood in place of water?

You can drink blood of course to a minimalistic amount (eg- a few teaspoons ) and also if blood is free from pathogens. But it should always be in very small amounts and from suitable donor. Here's ...
Ishi's user avatar
  • 559
17 votes
Accepted

What inactivates pepsin in infants?

EDIT: Thanks a lot to @abukaj for pointing out the mistake in my answer (and to @paracetamol for asking such a beautiful question). I am rewriting my answer to incorporate the (hopefully) correct ...
another 'Homo sapien''s user avatar
10 votes

Can a person survive on blood in place of water?

Here is a specific account of a person surviving at sea drinking turtle blood, while eating some fish and drinking some rain water. Several peoples have a habit of drinking raw animal blood, at least ...
Peter - Reinstate Monica's user avatar
7 votes
Accepted

What are the consequences of drinking water with food?

A moderate amount of water while eating will not dilute digestion ...according to Michael F. Picco, M.D. and the Mayo Clinic: There's no concern that water will dilute the digestive juices or ...
Dave Gruenewald's user avatar
7 votes
Accepted

What is a lethal dose of THC?

According to the abstract from this paper, the intragastric LD50 of $\Delta^9THC$ (tetrahydrocannabinol) in sesame oil using Fischer rats was 1270 mg/kg. Assuming rats and humans are identical (they'...
MattDMo's user avatar
  • 15.3k
7 votes
Accepted

Do humans produce rennin?

Scanning various reviews it seems that everyone who mentions the possibility of a human chymosin refers to a single paper. So for example this 2014 review has a single reference to a human chymosin: ...
Alan Boyd's user avatar
  • 22.8k
7 votes
Accepted

Why can't humans digest dietary fiber when we can digest starch?

"starches are held together with A bonds, dietary fibers are held together with B bonds, and the enzymes only work to break A bonds for X reason" What you wrote here is correct. ...
MattDMo's user avatar
  • 15.3k
6 votes
Accepted

How does horse extract the energy to needs from a relatively small digestive system?

The digestive system of a horse is by no means small: They have 15 to 21 m (50 to 70 ft) of small intestine, with a capacity of 38 to 45 L. They have a 1.2 m (4 ft) long caecum that holds 26 to 30 L. ...
Harry Vervet's user avatar
  • 2,482
6 votes
Accepted

Why do gram-negative bacteria attack the digestive system more than gram-positive ones?

Gastrointestinal infections can be caused by Gram positive and negative bacteria: Gram-positive: Staphylococcus aureus Clostridium difficile, botulinum and perfringens Listeria monocytogenes ...
Jan's user avatar
  • 8,079
5 votes
Accepted

Betaine HCl stomach pH

Betaine HCl (trimethylglycine) was present in over the counter "stomach acidifiers" but the US FDA says there is no evidence for its efficacy and has banned its use for this indication (source: US FDA)...
Bryan Krause's user avatar
  • 45.9k
5 votes

In which organs is water that we drink absorbed into the blood?

Role of the stomach in water absorption: The absorption of much of the ingested water from a hypotonic food already starts in the stomach due to osmotic reasons. If we study the mechanism of secretion ...
user 33690's user avatar
  • 1,955
5 votes

Can Fluoride be absorbed into the blood from within the mouth without swallowing?

Although I'm having a hard time finding a source that provides specific information on fluoride in toothpaste, this review explains that fluoride is most readily absorbed through intestinal epithelia ...
Forest's user avatar
  • 1,879
5 votes

Do humans produce rennin?

I think the answer is really that is isn't clear, though I only searched a bit and found mostly old papers. It seems like people have found immunoreactivity to anti-rennin antibodies in human infants,...
Bryan Krause's user avatar
  • 45.9k
5 votes
Accepted

Why porifera is classified to have an incomplete digestive system although it has no organs?

An incomplete digestive system is one in which there is only one opening. In our digestive system food is taken in by one opening (our mouth), the nutrients extracted and the remains are ejected by ...
User65535's user avatar
  • 212
4 votes

Is there evidence to suggest that nutrients in vitamin capsules are not as readily absorbed as the same nutrients in whole foods?

The answer probably varies for different nutrients. An informal article by ConsumerLab.com indicates that many vitamins are better absorbed from natural sources, but a few are actually more readily ...
augurar's user avatar
  • 1,584
4 votes
Accepted

Enzymes and Digestion

I suspect that the question reveals an incomplete understanding of enzymic catalysis and could more generally be rephrased as "If enzymes just speed up biological reactions, what makes the reactions ...
David's user avatar
  • 25.9k
4 votes
Accepted

Why are there not effective pharmaceutical treatments to prevent weight gain?

The two main factors are: Hunger is more complex to treat than pain (more pathways, more potential targets), and I would argue against your suggestion that we are good at treating pain: despite the ...
Bryan Krause's user avatar
  • 45.9k
4 votes

Does posture matter while drinking water?

The stomach is equipped with the pyloric valve to regulate transpyloric flow to the duodenum. Both cold and warm drinks stimulate a pattern of motility associated with retardation of transpyloric flow....
bandybabboon's user avatar
  • 10.4k
4 votes

Carbohydrates in acidic stomach

As for the digestion of fats there are two digestive enzymes active in the stomach: Lingual lipase (produced with saliva) Gastric lipase (produced in the stomach chief cells) Both have activity ...
adjan's user avatar
  • 2,106
4 votes

Do sharks fart?

Excellent question. Via Southern Fried Science: According to Daniella Rabaiotti, a postdoctoral researcher at the Zoological Society of London, sand tiger sharks are the only shark known to fart. They ...
angie_zorka's user avatar
4 votes
Accepted

Does digestion require hydrochloric acid?

Parietal cells use ion pumps to expel protons and chlorine ions into the lumen, which create the necessary acidic environment to denature pepsinogen into pepsin. It is the low pH environment that ...
Alex Reynolds's user avatar
4 votes
Accepted

How does the stomach handle continuous eating?

First of all, the stomach releases the digested food continuously. Simply put, during digestion the pylorus regularly opens a bit so that small food particles (< 1-2mm) are able to leave the ...
K. Biermann's user avatar
4 votes
Accepted

Do cats ingest everything that they lick off themselves during grooming?

Cat licking is partially to clean themselves (including of odors that might attract predators) but is also used as a cooling mechanism (they sweat little and so use evaporation of saliva as a cooling ...
PlantPromoter's user avatar
3 votes
Accepted

Absorption of pentoses in intestine

First, pentoses aren't a major source of nutrition, at least for humans. That said, pentose absorption works the same way a lot of nutrient absorption works: the "magic" of metabolism, with respect to ...
Bryan Krause's user avatar
  • 45.9k
3 votes
Accepted

What are the obstacles to "refitting" the human body's metabolism?

Yes, you got it right. The theory you're referring to is called the thrifty gene hypothesis. There have been several attempts at "rigging" metabolism to reduce the amount of surplus calories stored as ...
Roland's user avatar
  • 5,705
3 votes
Accepted

Special bacteria in infants

No, no human (or any other eukaryote lineage) are able to "create bacteria". The story you were told is wrong. However and interestingly, female parasitoid wasps seem to "create viruses" (Herniou et ...
Remi.b's user avatar
  • 68.1k
3 votes
Accepted

Product of reaction between HCl and bile

It's a simple acid-base-reaction. In order for bile to do its job, i.e work as an emulsifier, it needs to in a basic environment. Bile acids are therefore in their charged, negative state. The ...
Ashafix's user avatar
  • 695
3 votes

Could a mammal convert ingested dissolved CO2 to usable energy?

There isn't any biologically useful energy in CO2. In fact, humans and all other animals produce CO2 as a waste product at the end of metabolism specifically because it is low-energy. You don't need ...
Bryan Krause's user avatar
  • 45.9k

Only top scored, non community-wiki answers of a minimum length are eligible