Human Digestion

The digestive system of the human being comprises the gastrointestinal tract as well as the auxiliary organs of digestion (the tongue, salivary glands, pancreas, liver, and gallbladder). 

Human digestive system begins when food enters the mouth, where mechanical digestion begins with the action of mastication (chewing), which is a type of mechanical digestion, and the wetting contact of saliva.

Salad contains salivary amylase, an enzyme that aids in the digestion of starch in food. 

It also contains mucus, which lubricates the meal, hydrogen carbonate (which provides the optimal pH (alkaline) for amylase to act), and electrolytes (Na+, K+, Cl+, HCO3).

In the oral cavity, starch is degraded into disaccharide to a degree of around 30%. (mouth), Food will be in the form of a tiny, circular slurry mass termed a bolus after it has gone through the processes of mastication and starch digestion.

Because of the movement of peristalsis, it will pass down the oesophagus and into the stomach.

The production of gastric juice in the stomach initiates protein digestion. 

Gastric juice is mostly composed of hydrochloric acid and pepsin, which are both enzymes.Gastric juice in infants and toddlers also contains rennin, which aids in the digestion of milk proteins. 

When exposed to the first two chemicals, the stomach produces mucus and bicarbonates, which form a slimy layer that protects the stomach wall from the damaging effects of other chemicals, such as concentrated hydrochloric acid. 

Mucus also aids in lubrication, and bicarbonates help to neutralise the acidity of the stomach. 

Pepsin requires an acidic pH, which is provided by hydrochloric acid. 

Protein digestion takes place at the same time that mechanical mixing takes place, which is caused by waves of muscle contractions that move up and down the stomach’s wall as they pass through it. 

This allows the quantity of food to be further mixed with the digestive enzymes as a result of the process. 

Process of Digestion

In humans, the digestive process begins in the mouth and ends in the small intestine.  

The large intestines’ primary job is to absorb any remaining water from the undigested meal and to provide an environment for bacterial fermentation of components that cannot be digested anymore.

The digestion process is divided into the following steps:

Ingestion

Mastication is the very first phase in the process (chewing). 

The salivary glands, in conjunction with the tongue, assist in moistening and lubricating food before it is pushed down into the food pipe by the digestive system.

Movement and mixing

This procedure involves lubricating and modifying food before forcing it down the food pipe (using peristalsis) and into the stomach to complete the digestion process.

Secretion

A variety of enzymes and acids are secreted by the stomach, small intestine, liver, and pancreas to aid in the digestion process. It works by breaking down food particles into simple components that may be easily absorbed and assimilated by the body.

Digestion

The process by which complex food particles are broken down into simpler components in the presence of enzymes and acids generated by various digestive organs is called digestion.

Absorption

The small intestine is where the majority of the nutrients and minerals are absorbed, thus this is where the process starts. The large intestine is responsible for absorbing the excess water found in indigestible materials.

Excretion

This term refers to the process of eliminating indigestible substances and waste by-products from one’s body through defecation.

Briefly summarised, the digestion process is comprised of the six phases listed below:

1.Ingestion 

2.Mixing and Movement 

3.Secretion 

4.Digestion 

5.Absorption              

6.Excretion

The Length of the Human Digestive system

This system, also known as the digestive tract, the GI tract, the alimentary canal, or the alimentary canal, consists of a set of interconnected organs that extend from the mouth to the anus.

When we eat, our digestive system helps us to break down the food we eat so that we can acquire energy and nutrition from it.

Adults have a digestive system that can be up to 30 feet long. 

It is typically divided into eight parts: 

The mouth, the oesophagus, the stomach, the small intestine (also known as  small bowel ), and the large intestine (also known as  large bowel  or  colon),with the liver, pancreas, and gallbladder producing secretions to aid in digestion. 

Ingestion, secretion, propulsion, digesting, absorption, and faeces are the six functions performed by these organs collectively.

Conclusion

Digestion is the process by which big insoluble food molecules are broken down into smaller water-soluble food molecules, which can then be absorbed into the watery plasma of the bloodstream.

When consumed by certain organisms, these tiny chemicals are absorbed into the bloodstream via the small intestine and circulatory system. 

Digestion is a type of catabolism that is commonly divided into two processes based on how food is broken down: 

• Mechanical digestion 
• Chemical digestion.

 Mechanical digestion is the form of digestion that is most commonly encountered.

Pepsin is an enzyme that breaks down proteins into peptides or proteoses, which are then further broken down into dipeptides and amino acids by enzymes in the small intestine. 

Pepsin is found in the stomach and small intestine. 

According to some research, increasing the number of chews each mouthful boosts key gut hormones and may reduce self-reported hunger and food intake by as much as 10%.