Hot answers tagged

7

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: Henschel et al. detected a protease in the gastric aspirates of newborn infants within 6–10 h postpartum that was not pepsin [62]. The electrophoretic ...


5

Nonpathogenic E.coli are a component of the gut microbiome of humans and many other organisms. They are commensals, meaning that when they remain in the areas they have evolved to live in, and when they do not acquire virulence factors, they are benign. They live in our digestive tract and basically do nothing to harm us. In fact, commensal microorganisms ...


5

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 of HCl by the oxyntic cells of the stomach, HCl secretion favours water osmosis from the blood to the lumen both for protective reasons as well as to ...


5

Here's a simple cross-section of the stomach (from here): The stomach accomplishes much of its function by mechanically breaking down the swallowed food particles and mixing them with acid and enzymes into a sort of slurry. To do this, there are three major layers of muscle surround the stomach - from the outside, the longitudinal layer, the circular layer, ...


5

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, but that doesn't necessarly mean rennin is present, just something similar (which could even be a totally unrelated protein). On the genetics side, humans ...


4

Cortisol produced from the zona fasciculata of the adrenal cortex is directly caused by stress. According to http://en.wikipedia.org/wiki/Cortisol Cortisol stimulates gastric-acid secretion. Cortisol's only direct effect on the hydrogen ion excretion of the kidneys is to stimulate the excretion of ammonium ions by deactivating the renal glutaminase ...


4

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 stomach – it's not a batch process (see also this question). However, because humans tend to ingest a lot of indigestible materials (e.g. bones), there is a need to ...


3

The stomach linings generally secrete gastric acid (HCl, KCl and NaCl) and the native pH of the stomach is around 2. The longer you fast, gastric acid levels keep increasing until it reaches around 1-1.5. The food that you eat increases the pH levels of your stomach because the acid reacts with the food while digestion. Depending upon the type of food you ...


3

E. coli do not serve a human function but live inside our digestive system because our bodies can't prevent bacteria like them from living there. They live there because they can prosper and reproduce there. Most strains of E. coli do not cause problems for us, and by being part of the normal bacterial population in our gut they out-compete other, ...


3

Food only partially buffers the pH of stomach contents and acid is not the only esophageal irritant present in the stomach. The goal, therefore, is to have as little as possible present in the stomach when lying down (supine) to reduce risk of gastro-esophageal reflux (GER) through the lower esophageal sphincter (LES) into the esophagus. Avoiding meals just ...


2

Does the stomach need to start over after every bite? No. When the stomach digests food and some new food comes in, it just continues to digest the old and new food. The stomach releases small particles first and continues to crush large particles. In the stomach and small intestine, there are mechanoreceptors and receptors that detect gastric acid, amino ...


2

There can be many reasons about why too much candy (chocolate) can cause nausea. Lets talk about them one by one. Hyperglycemia - chocolate contains sugar, and too much sugar consumption can cause high blood sugar levels i.e. hyperglycemia. When blood sugar levels remain high for some time, it can cause nausea and vomiting, among many other symptoms ...


2

No. Even for an herbivore, digesting grass, or plants to be more general, is hard, because they contain cellulose. Herbivores have different parts of a stomach, whereas humans only have one compartment, so in herbivores, the plants (or grass) enter the first part of their stomachs called the rumen, which contains a salty solution that breaks down cellulose, ...


1

No, since the pH and the conditions are different in the different compartments (stomach, small intestine, colon) of the bowel. See this figure (taken from this website) for the differences: There are not that much bacteria in the stomach, so even even nothing else than acidic stuff comes out, the bacteria are not affected. And even when you have a severe ...


1

The below structure circled in green clearly is part of the stomach antrum. The location is correct, and the mucosal folds are characteristic. Kerckring valves of the small intestine and semilunar folds of the colon both look different.


1

The structure is called the lower esophageal sphincter: Basically, its function is to prevent the contents of the stomach, including stomach acid, from "backwashing" into the esophagus. The stomach is protected from acid by a protective layer of mucus, while the esophagus is not, so any number of medical issues which cause problems with this sphincter may ...


1

I've been spitting on anything red ( of biological origin (blood, wine, ketchup) for decades and seeing the stains dissolve and disappear like magic. Spit on it generously, let it soak for a few seconds, rub it in with your fingernails; see it disappear.


1

It would depend on the stain - and more specifically the material and staining agent. Saliva contains blood clotting agents so I doubt it would help with removing blood stains. The enzymes in saliva are unlikely to help with the stain removal. The water in saliva would be more likely to help, dissolving the stain. So your probably better off with water.


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