The Oesophagus is a tube-like structure that is hollow from the inside and made of fibres and muscles, through which food and liquids pass and reach the stomach from the mouth, aided by peristaltic contractions. The epiglottis prevents food from going down the larynx and lungs during swallowing. It lies behind the windpipe (trachea) and just in front of the spine. 

Oesophagus

The Oesophagus is the hollow, fibromuscular tube through which food and liquid pass and reach to the stomach from the mouth aided by peristaltic movements. The epiglottis (leaf-shaped flap in the throat) tilts backward to prevent food from going down the larynx and lungs during swallowing. It is found in the mediastinum (the part of the chest cavity surrounded by the lungs). It lies behind the windpipe (trachea) and just in front of the spine. 

In Humans, the Oesophagus normally begins around the sixth cervical vertebra, entering the diaphragm at the tenth thoracic vertebra, and ending at the cardia of the stomach, at the eleventh thoracic vertebra. It usually has a length of 10 to 13 inches and is 0.75 inches thick at its narrowest point.

Human Mucous membranes of the Oesophagus include a stratified squamous epithelium without keratin, smooth muscularis mucosae, and a smooth lamina propria. It is relatively rapid to replace the epithelium of the Oesophagus, which serves as a protective layer against food abrasion. It is surrounded by two muscular rings, the upper and lower oesophageal sphincter at the top and bottom, respectively. These sphincters are closed when food is not being swallowed.

Difference between the trachea and the Oesophagus

• Both the trachea (windpipe) and Oesophagus (food pipe) are muscular tubes located within the neck region, but they have very different functions.

• The trachea is a part of the respiratory system and transports air in and out of the lungs while the Oesophagus is a part of the digestive system which carries food and liquids into the stomach.

How does the food travel into the stomach?

Food is ingested through the mouth and when swallowed, peristalsis pushes the food down to the pharynx and then into the Oesophagus, and finally, it enters the stomach. When food is swallowed, the epiglottis retracts backward so it cannot enter the trachea. At the same time, the upper oesophageal sphincter also relaxes, allowing a bolus of food to enter the Oesophagus. Food is forced down the Oesophagus by periodic contractions of the oesophageal muscle. In addition to responding reflexively to food within the mouth, these rhythmic contractions also respond to the sensation of food in the Oesophagus. The lower oesophageal sphincter relaxes along with peristalsis.

Oesophageal varices

Abnormally enlarged or swollen veins present on the lining of the oesophageal tube are called oesophageal varices. This condition is often seen in people having major diseases like cirrhosis and hepatitis. It develops when the blood flow is restricted by a lump or cicatrix in the liver.

In order to bypass the blockages, blood takes other pathways and travels into minute blood vessels which are not capable of carrying large amounts of blood. This creates the high pressure in the veins which sometimes leads to rupturing of the veins and thus bleeding. Varices of the Oesophagus can be prevented or treated with a variety of medications and medical procedures.

Signs and symptoms

• Black and bloody stools
• Blood vomiting (hematemesis)
• Dizziness
• Unconsciousness

If the person has the following liver diseases, then the person might have the oesophageal varices:

• Hepatitis
• Easy bruising
• Ascites (abnormal buildup of fluid in the abdomen)

Causes 

A lump of tissue most often blocks the blood flow to the liver and causes swollen veins (oesophageal varices).This lumping increases the pressure within the veins that carry blood to the liver and forces the blood to take other ways through smaller veins to reach the liver. This high pressure sometimes ruptures the veins and leads to bleeding.

• Cirrhosis (fibrosis of the liver)
• Thrombosis (blood clots)
• Parasitic infections like schistosomiasis 

Preventions

• No consumption of alcohol
• Eat healthy and balanced diet
• Maintain a healthy body weight
• Less use of chemicals (insect sprays)
• Reduce the risk of hepatitis (avoid unprotected sex and sharing needles)

Conclusion

The Oesophagus is a tube-like structure that is hollow from the inside and made up of fibres and muscles, through this food and liquids pass and reach the stomach from the mouth aided by peristaltic contractions. The epiglottis prevents food from going down the larynx and lungs during swallowing. It is found in the mediastinum (the part of the chest cavity surrounded by the lungs). It lies behind the windpipe (trachea) and just in front of the spine. Enlarged or swollen veins present on the lining of the oesophageal tube are called oesophageal varices.