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Questions tagged [digestive-system]

Organs that play a role in digestion and/or absorption of nutrients: breaking down of food into smaller components that can be absorbed and used as for sources of energy, cellular/tissue building blocks, or cofactors for vital biochemical reactions.

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Can a person survive on blood in place of water?

This question: Can you get enough water by eating only fish? asks if a person could survive on fish alone. Can a person survive on fish and/ or blood alone of any species if stuck at sea or animal ...
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1answer
60 views

Does digestion require hydrochloric acid?

Would our digestion function any differently if we secreted something else, like sulfuric or nitric acid, instead? I'd assume an acidic environment may be required, but not sure if chloride is also ...
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67 views

How can we usually “trust a fart” not to be liquid or solid?

Jack Nicholson's character Edward Cole in the movie The Bucket List said ...and never trust a fart, and a search for Al Roker leakage White House will clear up any doubts what that's all about. How ...
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How does the symbiotic bacteria reaches a human caecum

My thought on this matter is that we have got a very high pH of about 1.8 in our stomach.So,most of bacteria who came in through food or just open mouth should be killed by it.So,how does a bacterial ...
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73 views

Which major salivary gland secretes maximum amount of salivary amylase and which one secretes maximum amount of Saliva

Actually I was studying about digestion and got this confusion about which gland(Parotid or Sub-mandibulary) secretes maximum amount of saliva and which one maximum amount of Salivary Amylase. Also,...
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1answer
123 views

Do sharks fart?

My son is 5 and I'm encouraging him to be curious and ask questions of the world around him. He asked if sharks fart and how does it smell? He feels that it would smell of fish and be disgusting. He ...
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1answer
165 views

Does pepsin enzyme digest other enzymes like other pepsin molecules

Pepsin digests proteins, as we know, but can it digest other enzymes that are actually made up of proteins, like digesting other pepsin molecules?
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3answers
77 views

Could a mammal convert ingested dissolved CO2 to usable energy?

I'm trying to find out if it's possible that a mammal could orally ingest dissolved CO2 and convert it to energy for body heat, organ function, etc. Unfortunately, most of the scientific sources I've ...
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26 views

Muscle layers of pharynx and gi tract

Why does pharynx have an internal longitudinal muscle layer and external circular muscle layer, while oesophagus and the rest of gastrointestinal tract have inner circular and outer longitudinal ...
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0answers
39 views

Can the human gut work with other type of gut bacteria?

I was wondering if the human body would be capable of functioning with, say, cellulolytic bacteria in their gut (instead of or in addition of their current bacteria), like that of ruminants and if ...
3
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1answer
140 views

Do cows chew in a preferential chirality?

One of the enduring myths in molecular physics, when talking about chirality as pertains the existence of enantiomers and the differences between them, is that the way cows chew is also chiral, i.e. ...
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1answer
80 views

Epidermal layer and muscle wall of colon?

First of all,I wanted to ask that whether epidermis is present in colon ? And if yes than how is muscle wall present with respect to epidermis. Can anyone give me a pic that has both the epidermis and ...
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1answer
39 views

Nonpancreatic digestion of tryglicerides

In an answer about coconut oil I can read the digestion of coconut oil does not involve in the Pancreatic digestive enzyme system In both primary and secondary school I have learned that fat needs ...
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1answer
1k views

How exactly is casein digested?

I mean it seems first step is rennin or pepsin digestion in stomach - then what happens with remaining peptides? I am interested in the whole process from casein to amino acids. Is there brush border ...
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0answers
39 views

Can gut flora affect what we can eat and what we cannot?

Back many years ago, I've read a mushroom guidebook, which I don't have anymore. I was unable to find the name of a particular mushroom. The book comprises listing of edible and poisonous mushroom ...
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2answers
59 views

What can pass through the intestinal membranes?

As I understand it, most substances need help to pass through the walls of the intestines. For example, in hepatic recirculation (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2781307/) bile salts are ...
2
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1answer
223 views

Why does enteral carbohydrate yield higher energy than parenteral?

The following is written in a well-known textbook of surgery: Each gram of enteric carbohydrate provides 4.0 kilocalories (kcal) of energy. Parenterally administered carbohydrates (eg, ...
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0answers
28 views

Sensitivity Along Digestive Tract [closed]

Suppose you swallowed a little capsule with a blunt poker which had some impulse of force applied every few seconds. What would be the sensitivity ordering (of lips, mouth, throat, esophagus, stomach,...
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3answers
4k views

Do humans produce rennin?

At school, we've been taught that human infants produce rennin/chymosin (which aids in the digestion of milk). More specifically, it is the peptic cells in the stomach which secrete prorennin, the ...
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1answer
686 views

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

I'm having a discussion with somebody regarding Fluoride usage. I told him that even if he doesn't like the idea of ingesting it, brushing and spitting it out will do you no harm. He then said this: ...
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1answer
165 views

Why do humans cook animal meat

Why do humans "need" to cook animal meat? It seems there's an aspect of safety to it: are other animals (eg, house cats, dogs) not vulnerable to the same diseases we get from modern food processing ...
3
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1answer
589 views

Which cells produce HCl produced in stomach? Don't these cells get destroyed by HCl?

Which cells produce HCl produced in the stomach? Or is HCl produced due to the translation of proteins. Don't these cells get destroyed by HCl?
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1answer
2k views

Bicarbonate concentration in saliva

From the picture it can be seen that Bicarbonate is secreted into lumen of duct of salivary glands by exchanging Cl- ions. So if flow rate of saliva is increased then its obvious that less Cl- is ...
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1answer
2k views

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

From biology classes I remember that water from food we eat is mostly 'sucked in' (absorbed into blood) in the colon. I guess the same is true for water we drink. But if I eat something, it will reach ...
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1answer
584 views

How are micelles formed from the byproducts of emulsification in fat digestion?

It is known that fat droplets are made into emulsion droplets via the addition of bile salts. It is then said that the emulsion droplets are made into micelles through some sort of lipase, which can ...
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1answer
946 views

Does the pyloric sphincter contract after ingesting only liquid?

At university, I was told by one of my fellow students that the reason why eating before going on an alcohol laden night out was a good idea, was because the pyloric sphincter contracted once food was ...
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2answers
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Does posture matter while drinking water?

I have heard a lot of people (where I am from, India) say that one must drink water sitting, not standing. Recently, I also came across a video that said the same thing (link). The reason given is ...
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2answers
384 views

Betaine HCl stomach pH

It seems betaine HCL is often recommended for those suffering from "low stomach acid" -- which, as I understand, is having too high stomach pH for proper digestion (especially for proteolysis via ...
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2answers
2k views

What inactivates pepsin in infants?

In infants, rennin helps in digestion of milk. Pepsin is also present in their stomach. Why do infants need rennin for milk digestion, at the first place? Why does pepsin not act on the milk ...
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1answer
711 views

What happens to the enzymes produced by the digestive system?

Our digestive system produces a lot of enzymes and they help to catabolize the food, and after completing their work are they excreted out or as they are also made up of proteins are they catabolized ...
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1answer
59 views

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

Hunger is caused by signals from the brain, so is there a way to suppress the signal of hunger in the same way we suppress the signal of pain with painkillers? If people felt less hungry, they would ...
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0answers
62 views

Eating possibly spoiled food in the fasted state - is it considered protective against the potential harm?

It is a known fact that the acidic environment in the stomach serves several purposes, such as providing suitable conditions for primary chemical digestion of food molecules and protection from ...
2
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1answer
123 views

How is chewing gum processed?

There is the common belief that Chewing gum takes 7 years to digest But is this actually true? Does it really stick to your intestines for 7 years, or is it processed like all foods, except it isn'...
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1answer
318 views

Why does a stomach come before the gizzard in birds?

Since the gizzard is for mechanical digestion, shouldn't that happen before the stomach digests the food with acids? (to make the morsels smaller)
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1answer
76 views

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

Recently I saw Inside nature's gaints episode on horse, and was fascinated about its internal organisation. And my question is that they have a very large lungs to accommodate, but a relatively ...
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1answer
320 views

Absorption of pentoses in intestine

Why pentoses are absorbed by facilitated diffusion in intestine? Wouldn't it be futile because , when the pentose concentration is lower in intestine, the pentoses would diffuse back to the intestinal ...
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1answer
461 views

Movement in microvilli

My textbook( COMPREHENSIVE TEXTBOOK OF PHYSIOLOGY VOL-1 by GK PAL) says: Microfilaments project into microvilli present on the epithelial surface such as on the intestinal mucosa, and extend up to ...
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3answers
640 views

How would a herbivore's digestive tract differ from a human's? [closed]

How would a herbivore's digestive tract differ from a human's? What are parts (organs, tissues, etc.) or enzymes that can't be found in one but is in the other? Also, is it correct to say that a ...
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1answer
423 views

What are the sites of nutrient digestion and absorption in the human GI tract? [closed]

Where does nutrient digestion and then absorption take place for different nutrients along the alimentary tract?
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1answer
410 views

How are nutrients absorbed by a pitcher plant?

I've read that pitcher plants thrive in nitrogen-poor soil, which is solved by dissolving insects and absorbing nitrogen that way. I have a few plants, and when a pitcher start to rot, I cut it off ...
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1answer
71 views

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

As a layman, I understand the problem of rising obesity like this: In the old times, humans could never get enough food, thus they would eat whatever they could get. This "program" is encoded in our ...
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1answer
385 views

Shape of feces in herbivores

Why do some herbivores like sheep, cow, and others excrete feces in a pellet (or biscuit or other) shape, while other species including humans do not do so? What is the reason for such an adaptation ...
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3answers
116 views

Special bacteria in infants

This question is similar to a previous question, but is not the same. I was told, you are born with a bacteria in your digestive track that are made by the body. Can a body in development create it'...
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0answers
47 views

What percentage of human excrement is toxic if ingested?

I have been considering food production, waste management and 3D food printing, particularly during space exploration. This led me to wonder if human excrement could be processed into raw materials ...
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1answer
2k views

Is there a link between digestion and nightmares?

A common belief is that eating too much before going to sleep can cause to have nightmares. In fact, I often experience it: I systematically have nightmares after eating too much in the evening. ...
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1answer
820 views

What are the consequences of drinking water with food?

Does drinking water with a meal release lesser energy/glucose into the blood stream due to a diluted digestive mixture ? For simplification : If a person eats 100 grams of cooked jasmine rice with no ...
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1answer
580 views

Product of reaction between HCl and bile [closed]

In the mammalian digestive system HCl is the main acid and bile is the main alkali. What is the product of the reaction between these two chemicals?
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1answer
44 views

Is it safe to feed an adult fire salamander with slime maggots? [closed]

As a reminder, maggots feed of a flesh, while fire salamander consumes his prey alive, without killing it. Can it happen that the maggot will start eating the salamander from the inside?
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1answer
506 views

How does the human stomach handle a mix of digested and undigested food?

As I understand it, the stomach digests the bolus into chyme and then passes the latter on to the small intestine. This process takes between 40 minutes and a few hours. However, what happens when ...
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1answer
45 views

Do I have to chew for digestion to kick in?

Liquid nutrient-rich products (such as Soylent) are consumed without chewing. But if I have to chew to initiate digestion, are those nutrients really "processed"?