When the nutrients have been used up to extract energy by burning with oxygen or other metabolic means, the waste products should be discharged out of the body. For further information, not all the food eaten will be stored inside the body, but some of the food will be wasted, as well. Therefore the waste has to be eliminated out of the body. Egestion and excretions both of them let the contents out of the body and sometimes these contents are released out through the same body part. Hence the real processes of excretion and egestion might cause some confusion. These two processes are very much different from each other with respect to the metabolic pathways and involved body organ systems. Therefore, it would be important to go through some information about these vital processes taking place inside the body of everyone.
What is Egestion?
Egestion is the process of discharging of undigested food particles or matter from the body of an animal. After the ingestion, food is being digested and absorbed into the body but there are some food particles that are indigestible and the body should get rid of them. In egestion, a collection of processes take place, and the procedure of discharge depends on whether the animal is unicellular or multicellular; the expulsion of undigested food materials are moved out of the body through the digestive tract and anus in multicellular organisms while the discharge is carried out through the cell membrane in unicellular organisms.
Apart from those differences, the metabolic pathway that leads to egestion is mostly the same in most animals for a particular food material. The discharged material is mainly called as the faeces or dung. Egestion is carried out via anus or the cloaca, but in some exceptional cases like invertebrates such as flatworms discharges their waste food as faeces through the mouth. In the process of egestion, the discharged food particles are usually thick or sometimes semisolid this is because the maximum amount of water is utilized in absorption by the animal body when the food passes through the large intestine.
What is Excretion?
Excretion is the process of discharging of substances that have gone through one or several metabolic processes inside the body of an animal. So it basically takes place when there is a chemical reaction. Exhaling step of respiration, urination, and sweating are the major excretory processes of an animal. Cellular respiration produces carbon dioxide and that is transported into the lungs through the circulatory system, and the lungs execute the exhaling process.
However the major excretory process is urination, and which is extremely crucial for the maintenance of ionic and water balance of the body
Excretion also take place in plants. Plants excretes excess oxygen and carbon dioxide . Carbon dioxide is released during respiration while oxygen is released during the process of photosynthesis.
What is the difference between Egestion and Excretion?
- Excretion is the process of discharging of metabolic waste whereas egestion is the process of discharging of undigested food in the gut this occurs in multicellular organism , in unicellular organism it takes place on the surface of the cell . In human egestion can be done by defecating or even vomiting.
- The matter that has been discharged has never passed through a cell in egestion, while it has in excretion.
- Egestion can be carried out through the anus and rarely through the mouth while on the other hand excretion can be carried out through many different organs such as nose or mouth, skin, cloaca or sex organs and in the stomata of plants.
- Egestion can be carried out in animals but not plants . While excretion can take place in both .