Process of Egestion in Human Beings

The human digestive system comprises a long muscular tube and various accessory organs like those of the salivary glands, pancreas and gallbladder. These are responsible for food ingestion and digestion, further absorption of digestion products and the elimination of undigested materials. Life processes in the human body are amazing. These processes not only function on their own but the main reason that makes them even more interesting and amazing is actually how smart they are. Digestion is one of the most key steps that is needed to make sure that we are living and it is the reason why it is a very important part of our existence. The waste products that are being formed during the process of digestion, are accumulated in the form of faeces and the process of removal of this waste from the body is referred to as egestion. 

Egestion in Human Beings

The food reaches the end of the small intestine, from which all the digested food products, along with the minerals and vitamins that are useful to the body, have been removed from the watery contents. Only the indigestible constituents of food like cellulose from the consumption of plant-based foods are remaining. These materials are then transported to the large intestine. Here, recovery of water and electrolytes (sodium, chloride) from indigestible food matter takes place, along with the formation and storage of faeces and fermentation of some of the indigestible food matter. 

It is estimated that there are around 500 species of bacteria present in the large intestine, and these friendly bacteria undergo a variety of functions. For example, undigested carbohydrates (such as fibre) are metabolised to short-chain fatty acids, and small amounts of vitamins, particularly vitamin K and the vitamin B groups, are formed for absorption into the blood. Once the undigested material accumulates in the rectum, it coordinates a response that results in the evacuation of the waste through the anus.

Excretion 

There are a variety of chemical reactions that take place inside a living body. That further results in a variety of waste products that are constantly being generated. The living body is required to remove these wastes. Excretion refers to the elimination of these metabolic waste products from the body. This process of removal of wastes from the cells of living organisms is known as excretion. The organ system that is responsible for the removal of these wastes is known as the excretory system.

Waste Products

• Nitrogenous Waste Products: These are the major waste products that are formed during the breakdown of extra amino acids, nucleic acids and alkaloids. Some of the important nitrogenous waste products are urea, uric acid, creatine, creatinine and ammonia.

• Non-nitrogenous Waste Products: these include oxalic acid and lactic acid.

• Excess Chemicals: these include excess minerals, drugs, pigments, vitamins, hormones, cholesterol, etc.

• Bile Pigments: it includes bilirubin, biliverdin and urochrome.

Excretion in Human Beings

The human body excretes several wastes in the following ways:

• Through exhaled air:  carbon dioxide, which is formed after respiration, is expelled out of the body with the exhaled air.

• Through sweat: our skin also acts as an excretory organ. It has small outer openings known as sweat pores. The human body gets rid of a small quantity of urea, salts, and water through sweat that is secreted by the sweat glands situated under the skin. Sweating is important since it helps in regulating body temperature. It helps to keep the body cool by losing the body heat, as sweat evaporates off the skin.

• Through the kidney: a large number of nitrogenous wastes like urea and uric acid are produced inside the body. Urea is a product of the combination of carbon dioxide and ammonia. It is excreted out from the body in the form of a pale yellowish-coloured liquid known as urine. Urine comprises about 95% water and the remaining 5% consists of urea, uric acid, and minerals. The formation of urine takes place inside the kidneys. The main excretory organ in humans is a pair of kidneys.

Ingestion

It refers to taking in a material (like any foodstuff) inside the mouth or body.
It can also refer to the process or act of engulfing particles via cells (i.e. phagocytic cell).

Conclusion

In unicellular organisms, the undigested food is transported up to the cell membrane and then released outside of the body. Some multicellular animals do not possess a specialized digestive system. As it can be seen, in hydra, the food gets digested in the stomach sac, and the food is egested out through the mouth. With this, we come to an end to this topic. We hope you were able to clear all your concepts regarding egestion in humans, excretion and ingestion processes. We suggest you focus on understanding the topic rather than just mugging it up.