The key difference between esophagus (oesophagus) and trachea is that the esophagus is the muscular tube that connects the pharynx with the stomach of the vertebrates, while the trachea is the tube that connects the lungs with the pharynx.
Esophagus (oesophagus) and trachea are two very different parts or organs that belong to two distinctive systems of the body. The oesophagus is a part of the alimentary tract while the trachea is a main part of the respiratory system, but both these organs function as connectors of those respective systems.
CONTENTS
1. Overview and Key Difference
2. What is Esophagus (Oesophagus)
3. What is Trachea
4. Similarities – Esophagus (Oesophagus) and Trachea
5. Esophagus (Oesophagus) vs. Trachea in Tabular Form
6. FAQ: Esophagus (Oesophagus) and Trachea
7. Summary – Esophagus (Oesophagus) vs. Trachea
What is Esophagus?
The esophagus (or oesophagus) is the muscular tube that connects the pharynx with the stomach of the vertebrates. The esophagus allows the food to pass from the mouth into the stomach. According to the location, the esophagus has three main parts: the cervical (anterior-most) part, the thoracic (middle) part, and the abdominal (posterior-most) part.
Usually, the esophagus is about 25 – 30 centimetres long. It has many types of cells and tissues incorporated. The mucosa is the innermost layer consisting of no keratinised protective cells (stratified squamous epithelium), mucus-secreting cells, and smooth muscles. The next layer is the submucosa with mucus secreting esophageal glands and some connective structures. The muscularis externa is the next outer layer, composing mainly the muscles. Its composition changes with the location of the esophagus; the anterior part has striated muscles; the middle part has smooth and striated muscles, and the posterior part has only smooth muscles. Adventitia is the outermost layer covering the esophagus with loose connective tissues.
Figure 01: Esophagus (Oesophagus)
There are three anatomically important constrictions in the oesophagus; the first one is the oesophageal inlet due to the pharynx and cricoids cartilage, the second constriction due to the aortic arch, and the third one is found where the oesophagus crosses the diaphragm. Finally, the oesophagus ends at the junction at the stomach, known as the gastro-oesophageal junction.
What is Trachea?
The trachea is also known as the windpipe, and it is the tube that connects the lungs with the pharynx. The trachea allows the passage of air, being taken through the nostrils, into the lungs. The trachea is about 10 – 16 centimetres long and contains an inner lining of pseudo-stratified ciliated columnar cells. The goblet cells in the trachea are responsible for producing mucus in order to trap foreign solid particles before reaching the lungs. Usually, the ciliated epithelium wafts those particles out of the respiratory system using cilia. The C-shaped cartilaginous structures (rings) are present in order to maintain the shape of the windpipe.
Figure 01: Trachea
The tracheal muscles are extremely important in facilitating rapid airflow during coughing and sneezing by contracting the incomplete ends of the cartilaginous rings of the trachea. The anterior end of the trachea is the larynx, and the epiglottis prevents food from entering the respiratory tract. However, of all the vertebrates, only the air-breathing animals have trachea, i.e., the fish and related lower vertebrates do not have trachea.
What are the Similarities Between Esophagus (Oesophagus) and Trachea?
- Both the esophagus and trachea are located in the thoracic (chest) cavity.
- Both structures are tubular.
What is the Difference Between Esophagus (Oesophagus) and Trachea?
The esophagus is a part of the digestive system, while the trachea is a part of the respiratory system. The esophagus is a muscular tube with varying shapes, while the trachea has a general internal shape with cartilaginous structures. Moreover, the oesophagus is longer than the trachea. The inner linings of the two structures are also different; the trachea has cilia, but not the esophagus. In addition, the esophagus connects the pharynx with the stomach, while the trachea connects the larynx with the lungs.
Below is a summary of the difference between esophagus (oesophagus) and trachea in tabular form for side-by-side comparison.
FAQ: Esophagus (Oesophagus) and Trachea
What is the difference between esophagus and oesophagus?
There is no difference in meaning between “esophagus” and “oesophagus.” The spelling “esophagus” is commonly used in American English, while “oesophagus” is the British English spelling.
Why is there a difference in the structure of the oesophagus and trachea?
The esophagus is mainly involved in the transport of food from the mouth to the stomach, so it has a muscular wall designed for peristaltic contractions. In contrast, the trachea is part of the respiratory system, conducting air to and from the lungs. It has cartilaginous rings to maintain its shape and prevent collapse, facilitating the passage of air during breathing.
Summary – Esophagus (Oesophagus) vs. Trachea
In brief, the esophagus is a part of the alimentary tract, while the trachea is a main part of the respiratory system. The key difference between esophagus (oesophagus) and trachea is that the esophagus is the muscular tube that connects the pharynx with the stomach of the vertebrates, while the trachea is the tube that connects the lungs with the pharynx.
Reference:
1. “Esophagus.” Wikipedia. Wikipedia Foundation.
2. “Trachea.” Wikipedia. Wikipedia Foundation.
Image Courtesy:
1. “Tractus intestinalis esophagus” By Olek Remesz (wiki-pl: Orem, commons: Orem) – Own work (CC BY-SA 2.5) via Commons Wikimedia
2. “Blausen 0865 TracheaAnatomy” Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. – Own work (CC BY 3.0) via Commons Wikimedia