Tag: stomach

Posted in Psychology & Medicine

Viscera: Stomach

Posted on by Jinavie

(Learn more about the organs of the human bodies in other posts in the Viscera series here: https://jineralknowledge.com/tag/viscera/?order=asc)

The stomach is an organ that is well-known, so much so that the abdomen is often colloquially referred to as “the stomach”. It is an important organ that is part of the digestive tract, responsible for breaking down food that comes in through the mouth then the oesophagus. The stomach lies centrally and just below the sternum, surrounded by the liver on the right, spleen on the left and pancreas below.

Food is broken down primarily by the mouth via chewing. Once you swallow, the food is squeezed through the oesophagus until it is dumped into the stomach. The stomach produces a very strong acid (hydrochloric acid, pH 1~2), which dissolves the chewed food. It enhances this process by contracting its powerful wall muscles to churn and mix the food. Once it is nicely dissolved into a thick liquid, it releases it into the duodenum (the first part of the small intestine).

If the stomach uses strong acid to breakdown food, which is organic matter, how come it does not digest itself? This is because the lining of the stomach is coated with a substance called mucin which protects the stomach wall from being corroded by acid. However, the stomach is not perfectly safe from the acid it produces. If the stomach becomes inflamed, the production of mucin and self-repair process of the stomach is limited and acid begins dissolving the stomach lining. This causes peptic ulcers to form, which is essentially a hole in the lining of the stomach, causing severe abdominal pain and occasionally bleeding. Peptic ulcers are commonly caused by an infection by a bacteria called Helicobacter pylori. It may also be caused by severe stress and anger or medications such as NSAIDs (non-steroidal anti-inflammatory drugs, e.g. ibuprofen, diclofenac/Voltaren).

Posted in Science & Nature

Trophallaxis

Posted on by Jinavie

One of the key characteristics of social animals is the act of helping other members of the society. People often think that nature is ruled by “the survival of the fittest” and selfishness for survival, but societies are common in the animal kingdom. For example, even insects, that people consider “inferior”, such as ants build massive empires and cities, forming an unbelievably intricate and efficient society.

In the wild, all animals must find food to live, but due to competition and the environmental conditions, there are days when an animal cannot find enough food. For times like this, ants have a second communal stomach which they fill with leftover food after a meal. They then approach a hungry colony member and offers it a meal. If the other ant accepts, the two ants then lock their mouths together and one ant brings up the food in the communal stomach into the other ant’s mouth. Benefaction such as this allows for a smooth functioning of the society.

There is another role of trophallaxis (the transfer of nutrients via the mouth-to-mouth route described above): communication. Ants rub their antennae together to identify each other’s pheromones, which acts as identification such as what colony they are from and their role in the colony. Some scholars suggest that trophallaxis is the origin of the kiss.

The act of offering pre-stored food to comrades is also found in vertebrates such as birds and bats. For instance, some species of birds feed, return to its nest and then vomits the food for the young to feed on.
Helping those in need to create an efficient and functional society, and reaping the rewards of quid pro quo: that is the way of the philosophy of 1 + 1 = 3.