Digestive System

Digestive system

Introduction

When we eat something, the food has to be digested in order to give us nourishment and keep us alive. For this complex process of digestion, the digestive system is present in a human body. The digestive system holds key importance in the human body. The system comprises of a set of organs and tracts. Each of them is working in its unique way. The result is the small molecules of nutrition that can be easily absorbed by the linings of the digestive system. The result is the waste material referred as Feces.

Discussion

Food is of vital importance in order to keep a person healthy and alive. The word “digest” means break down. It is a process of catabolism of larger food particles into tiny particles so that they can be easily absorbed into the blood and consumed by the body. The digestive system, also called the gastrointestinal tract, consists of a set of organs, closely linked with each other in terms of their anatomy and functions.



Structure of the Gastrointestinal tract

The Gastrointestinal tract comprises of a number of inter-related organs. The tracts start from mouth and ends at the anus.

The oral cavity

The process of digestion begins write after ingestion of food from the oral cavity. This cavity has two parts

Mouth

Pharynx

Mouth

The initial mechanical and chemical digestion of food starts from the mouth. The mouth consists of, tongue, teeth and saliva.

Teeth: teeth are responsible for the breakdown of food called mastication. This results in the mechanical digestion of the food particles (Heinemann , 2000)

Tongue: It is responsible to mix the digested food and compile it

Saliva: The saliva consists of amylase, mucin, buffers and anti-bacterial agents. Amylase is special salivary enzymes responsible for primary digestion of carbohydrates and starch. The mucin has a slippery protein called mucus, which lubricates the food and makes it easy to be broken down and swallowed. These processes results in the formation of a moistened, soft mass called bolus (Barret, E.K, et.al , n.d)

Pharynx

The pharynx is a common opening for both, the food and the airways. There is a flap of connective tissues, epiglottis. It closes over the trachea when the food is passing towards the esophagus. This prevents air choking. (Werner K., 1993)

Esophagus

Esophagus is a long tubular portion of the digestive tract, which joins the oral cavity with the stomach. This tubes lack the digestive glands. Esophagus has two notable features; peristalsis and mucous secretions. Peristalsis: peristalsis in the esophagus is a rhythmic process of contractions and relaxations. This pushes the food forward and helps the food reach the stomach. Mucous: it is a slippery substance secreted by the linings of the esophagus. This mucous secretion helps to soften the food. The bolus now enters the stomach.

Stomach

Anatomy

Human stomach is a bean shaped organ anatomically located at the left side of the abdominal cavity, just below the diaphragm. The human stomach has 4 regions, namely the cardiac region, fundus, body and the pylorus. Below the fundus of the stomach lies the ...