Food Digestion, Absorption and release of Energy

What is meant by Food Digestion?

Food is one of the basic requirements of all living organisms. The major components of our food are carbohydrates, proteins and fats. Vitamins and minerals are also required in small quantities. Food after digestion provides energy and organic materials for growth and repair of tissues.

The water we take plays an important role in metabolic processes and also prevents dehydration of the body.

Bio-macro-molecules that we take in food is utilize directly by our body in their original form. They are broken down and converted into simple substances in our digestive system. This process of conversion of complex food substances to simple absorb-able forms is called food digestion after that energy is released.

Food digestion and release of energy is carried out by our digestive system by mechanical and biochemical processes called metabolism.

Food Digestion & Energy system

Human digestive system is mainly consists of an alimentary canal and its associated glands. It is shown in following figure.

Alimentary Canal

This is the longest part of human digestive system. It begins with mouth and opens out at posterior through the anus. The mouth leads to the buccal-cavity or oral cavity. This oral cavity leads into a short pharynx which serves as a common passage for food and air. A cartilaginous flap called epiglottis prevents the entry of food into the wind pipe during swallowing.

Stomach

The main part of alimentary canal is stomach. The stomach is located in the upper left portion of the abdominal cavity. It opens into the first part of small intestine. Small intestine is distinguishable into three regions called duodenum, jejunum and a highly coiled ileum. Ileum opens into the large intestine.

Large Intestine

Large intestine consists of caecum, colon and rectum. Caecum is a small blind sac which hosts some symbiotic micro-organisms. A narrow finger-like tubular projection, the vermiform appendix which is a vestigial organ, arises from the caecum. The large intestine ends into the rectum which opens out through the anus.

Mucosa

The innermost layer lining of Alimentary canal is called the mucosa. This layer forms irregular folds in the stomach and small finger like folding called villi in the small intestine which helps in absorption and assimilation.

Digestive Glands

The digestive glands associated with alimentary canal include the salivary glands, the liver and the pancreas.

1.Salivary Glands

These are the glands present in mouth oral cavity produce saliva and enzymes. It mixes with the food and digestion process first started here.

2.Liver

It is called the largest gland of the body weighing about 1.2 to 1.5 kg in an adult human. It is situated in the abdominal cavity. The bile secreted by the lever is stored in a thin muscular sac called the gall bladder.

3.Pancreas

It is a mixed gland (means combination of exocrine glands and endocrine glands) as it generates both exocrine juices (i.e. enzymes) and endocrine juices (i.e. hormones) secretions. It is situated between the limbs of U shaped duodenum. The exocrine portion secretes an alkaline pancreatic juice containing enzymes and the endocrine portion secretes hormones, insulin and glucagon.

Disorders in Digestion System

The inflammation of the intestinal tract is the most common ailment due to bacterial or viral infections. The infections are also caused by the parasites of the intestine like tape-worm, round-worm, thread-worm, hook-worm, pin-worm, etc. Common diseases caused due to disorders of digestive system are –

Jaundice –

The liver is affected, skin and eyes turn yellow due to the deposit of bile pigments.

Diarrhoea –

The abnormal frequency of bowel movement and increased liquidity of the faecal discharge is known as diarrhoea. It reduces the absorption of food.

Constipation –

In constipation, the faeces are retained within the rectum as the bowel movements occur irregularly.

Indigestion –

In this condition, the food is not properly digested leading to a feeling of fullness. The causes of indigestion are inadequate enzyme secretion, anxiety, food poisoning, over eating, and spicy food.

Vomiting –

It is the ejection of stomach contents through the mouth. This reflex action is controlled by the vomit center in the medulla. A feeling of nausea precedes vomiting.

Supplementary Nutrients for Digestion

Here, we are presenting some excellent supplementary nutrients to keep your digestive system working properly with adequate metabolic rate.

Energy from Food

All parts of our body i.e. muscles, brain, heart, liver etc. need energy to do their functioning. This energy comes from the food we eat.

Acids and enzymes, secreted from the digestive glands mixes with the food we eat and digested in the stomach. When the stomach digests the food, the carbohydrate (i.e. sugars and starches) in the food breaks down into another type of sugar called glucose. This is the form of energy which is beneficial to our body.

The stomach and small intestine absorb the glucose and then release it into the blood stream. This energy can be used immediately or stored in our bodies in the form of fat to be used later.

Supplementary Nutrients for Energy

Here, we are presenting some excellent supplementary nutrients to keep your energetic whole the day keeping you active always.