99

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 grams of protein yields the amount of urea that requires 1,360 mL of water to be excreted in urine (calculated from here); 2 grams of sodium requires about 140 ...


20

I wouldn't say that a human is "likely" to get sick by drinking from a puddle, I'd say "at some risk". It isn't desperately dangerous, although don't take that as a recommendation. There are many infections you can get from water (bacterial, viral, amoebal, and I presume fungal). You don't want to risk them, but probably won't actually encounter them in that ...


18

Mucous-producing cells at the neck of the gastric pits create a layer of protective mucous covering the stomach lining. This mucous layer includes bicarbonate ions which act as a chemical barrier against the protons in gastric juice. See here for some evidence. The stomach lining stays protected because the mucous layer is continuously replenished.


18

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 why The strange fact is, blood, when drank, is toxic. When confined to places where blood is supposed to be — such as the heart, vessels, and so on — it is ...


17

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 background knowledge this time. NEW ANSWER: As @paracetamol and @AlanBoyd (in their answer) pointed out the lack of credible support for the claim that infants ...


16

No, you cannot live off of semen. A source from Columbia.edu: A typical ejaculation fills up about one teaspoon; the actual amount is determined by a man's age (younger men usually make more semen), when he last ejaculated, and how long he's aroused before ejaculating, among other factors. Contrary to what you've heard, semen is not loaded with calories. ...


16

I'm sure it varies wildly based on the animal and what they're eating. In general, if in the course of an animal's natural feeding process it picks up a little dirt, it has evolved to cope with that. Animal's behaviors and guts have evolved to fit their food source and lifestyle. For a behavioral example, seals will eat rough rocks to help breakdown bones ...


16

One of the most common toxins in mouldy food/bread is aflatoxin. The exposure to high amount of aflatoxin can lead to acute aflatoxicosis with fulminant hepatic failure and even death. While mild exposure to aflatoxin could be asymptomatic, it is better not to take a chance considering possible complications (citation from the link above): Aflatoxins ...


13

The blood pH is tightly controlled since variations are quite dangerous for us. Under normal circumstances the pH is 7.4 (with a normal range between 7.35 and 7.45). Below that we are talking about acidosis, above it about alkalosis. If the blood pH goes about 7.8 or below 6.8, death will occur. This pH is maintained by the Bicarbonate-buffering system, for ...


12

The hoatzin has a digestive system that makes use of bacterial fermentation. Many other birds also consume grass, e.g. ostriches, ducks and geese. There's also a large body of literature on how birds can digest cellulose.


10

Quite a bit can be absorbed through the mouth. Most commonly, starches are broken down to maltose (two glucose molecules formed by a condensation reaction) and are easily absorbed by the bloodstream. A lot of other factors balance into this, ie pH, lipid solubility, and molecular weight. Generally, if a substance is easily dissolved in saliva, it can be ...


10

First, there are two different isomers of the lactic acid, the L(+)- and the D(-)-form. Both differ in the position of the OH-group in the molecule: Both turn polarized light in different ways, the D(-) to the left and the L(+) to the right. The physiological form of lactic acid for the human body is the L(+) form, which is taken up in the gut and then ...


10

Satiety is complex, and there are several kinds of satiety, all of which come into play in different circumstances. Things that decrease or halt our eating are called satiety signals. Different satiety signals are put out by different substances (carbohydrates, fats and proteins) as well as by things like gut stretching and other signals. There is also a ...


10

Dizziness after eating, which can lead to falls and passing out, is called postprandial hypotension, and as the heart is indeed responsible for responding to hypotension by increasing it's rate - which can be seen in any number of clinical scenarios from blood loss to standing up too suddenly - failure to do so, for any reason including heart disease, can ...


10

Yes, they do. For a look at survival of Lactobacillus and other bacterial species after multiple freeze/thaw cycles, check out Harrison 1955 (below). The awesome hand-drawn graphs show that many bacteria survive after being frozen for 11 weeks. There's also a figure on the following page showing that many bacteria also survive after multiple freeze-thaw ...


10

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 for ritual purposes; here is a recent account. They probably drink more than a few spoons full so that the Lifescience article quoted by Ishi appears alarmist.


9

Wow! What an interesting question! I did a bit of searching around, and here's what I found. It looks like the baby kangaroos, or joeys, do in fact produce excrement while in their mothers pouch. The mother kangaroo uses her tongue to clean her joey and her pouch. I found this information in a couple of differently places by doing a google search for "...


9

Short Answer: There was an interesting paper that dealt with the pH of urine when citric acid was consumed. The summary was: There was no increase in urinary pH or total nitrogen in 24 hours collection of urine. What This Means: The food we take does not affect the blood pH directly. Acidic food will cause increased secretion of alkaline components into ...


9

Short answer Various inhalants, most notably organic solvents including those used in paint and glue suppress appetite. Background From the Division of Alcohol and Drug Abuse I learned the following: Initial effects [of various inhalants] include nausea [...], and a loss of appetite. And the Humanitarian Irin News reports the following on Nepali ...


8

The function of bile produced by the liver and concentrated in the gall bladder is to aid in fat digestion. Bile acts as an emulsifier to allow the fat to be packaged into small droplets, micelles. The breakdown of fats into small micelles greatly increases the surface area for lipases produced by the pancreas have to act on. These are then absorbed ...


8

How are diabetes and obesity connected in light of low lipase activity? Short answer: There's more than one type of diabetes. (And to complicate things, there's also more than one type of lipase. It's unclear from the question which type were mentioned in what you read.) Diabetes mellitus is usually divided into Type 1 (insulin-deficient) and Type 2 (...


8

Sugar (be it sucrose, glucose, fructose or honey) does not have emetic properties in any concentration, unless there is a personal (and highly individual) psychological adverse reaction to sweet substances. Sugar is not a local gastric irritant (like dishwashing detergent, or syrup of ipecac, copper sulphate, zinc sulphate; yellow mercuric sulphate, ...


7

Cause of this secret are tight junctions and mucous. As Wikipedia explains: Tight junctions, or zonula occludens, are the closely associated areas of two cells whose membranes join together forming a virtually impermeable barrier to fluid. It is a type of junctional complex present only in vertebrates. The corresponding junctions that occur in ...


7

Animals do sometimes experience health problems from microbiologically polluted water. But they drink it, because they probably don't have as many options to choose from as humans have. Additionally, wilderness is very harsh, sick animals get eaten by predators quickly, so the short term evolutionary selection pressure in wilderness works very strongly in ...


7

For several reasons, I seriously doubt that this has been studied extensively. There is a good reason to study absorption through oral mucosa because a drug or glucose can be held there by people who needing rapid absorption of a drug (e.g. sublingual nitroglycerine) or by people who may be unable to swallow (e.g. a hypoglycemic individual who has lost ...


7

According to Crispim et al 2011, caloric intake late at night is correlated negatively with sleep quality: We conclude that food intake during the nocturnal period is correlated with negative effects on the sleep quality of healthy individuals. Indeed, food intake near the sleeping period (dinner and late night snack) was negatively associated with sleep ...


7

Could you suggest a good source for beginners. - Louis Somers The interactions between the human body and its microbiome are quite complex. I am going to provide you with an answer that will be based on your comment that you would like an answer from a beginners perspective. For simplicity sake I will keep the answer to humans as the host organism, though ...


7

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're not), for an average-sized adult human weighing 70 kg (~155 lb.), the median lethal dose would be 88.9 grams, or about 3.1 oz. Keep in mind that's 3.1 oz. of ...


7

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 interfere with digestion. In fact, drinking water during or after a meal actually aids digestion. Water and other liquids help break down food so that your body can ...


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