Briefly describe the pathways and the process of ingestion, digestion, absorption and transport involved when a person has eaten buttered polony sandwich?
Answers
Answer:
The Human Digestive System
The digestive system of the human body comprises a group of organs working together to convert food into energy for the body. Anatomically, the digestive system is made up of the gastrointestinal tract, along with accessory organs such as the liver, pancreas and gallbladder. The hollow organs that make up the gastrointestinal tract (GI tract) include the mouth, stomach, oesophagus, small intestine and large intestine that contains the rectum and anus.
Human Digestive System and Nutrition involve the intake of food by an organism and its utilization for energy. This is a vital process which helps living beings to obtain their energy from various sources. The food which we eat undergoes much processing before the nutrients present in them are utilized to generate energy. This processing is known as digestion. Humans and other animals have specialized organs and systems for this process.
The digestion process involves the alimentary canal along with various accessory organs and organ systems. In humans, the process is quite simple due to our monogastric nature. This means that we have a one-chambered stomach, unlike other animals such as cows, which have four chambers.
Some parts of nervous and circulatory systems also play a significant role in the digestion process. A combination of nerves, bacteria, hormones, blood and other organs of the digestive system completes the task of digestion.
Let us have a detailed look at the human digestive system, its parts and functions.
Digestion Process
The process of digestion begins from the mouth and ends in the small intestine – the large intestines’ main function is to absorb the remaining water from the undigested food and enable bacterial fermentation of materials that can no longer be digested.
The alimentary canal or the gastrointestinal tract is a series of hollow organs and tubes that begins from the mouth cavity and continues into the pharynx, through the stomach, small intestines, large intestines, and finally ending at the anus. Food particles gradually get digested as they travel through various compartments of the gastrointestinal tract.
The digestion process takes place in the following steps.
Ingestion
The very first step involves mastication (chewing). The salivary glands, along with the tongue, helps to moisten and lubricate food, before being pushed down into the food pipe.
Mixing and Movement
It involves the process of lubricating and manipulating food and pushing it down the food through the food pipe (using peristalsis), and into the stomach.
Secretion
The stomach, small intestine, liver, and pancreas secrete enzymes and acids to aid the process of digestion. It functions by breaking down food particles into simple components and easily absorbable components.
Digestion
The process of converting complex food particles into simpler substances in the presence of enzymes and acids secreted by different digestive organs.
Absorption
This process begins in the small intestine where most of the nutrients and minerals are absorbed. The excess water in the indigestible matter is absorbed by the large intestines.
Excretion
The process of removing indigestible substances and waste by-products from the body through the process of defecation.
In a nutshell, the digestion process consists of the six following steps:
Explanation: