Trachea- Anatomy, Location, Function and Pathology

What Is Trachea?

The trachea is the part of the respiratory system that connects the larynx to the bronchi, which in turn connects to the lungs. The trachea forms the passageway for the air to flow. The airflow will happen only if the passage is intact. So as to maintain the trachea intact and open for uninterrupted airflow, the trachea has rings of cartilage. Also, it is lined by mucus glands to produce mucus throughout the trachea. These mucus present in the trachea provide humidity to the air passing by. The mucus lining also protects from foreign bodies like dust, pollen, allergens, and other debris from entering the respiratory organ to some extent.

What Is the Anatomy of Trachea?

• The trachea is a firm yet flexible structure that forms the passageway for the air to the lungs.

• In order to maintain the firmness of the trachea, it is lined with cartilage rings. The cartilage rings found in the trachea are “C” shaped and do not cover the trachea completely from anterior to posterior. These cartilages are found in the anterior and lateral aspects of the trachea, and the posterior wall is formed by a muscle running longitudinally known as the trachealis muscle.

• There are about 18 to 22 ‘C' shaped cartilaginous rings throughout the trachea. The space between each cartilage is covered by an intercartilaginous membrane.

• The trachea is lined by mucosa. This mucosa has cells called goblet cells which produce a moist and sticky substance called mucus. The mucus maintains the moistness of the air passing by the trachea and also entraps the foreign substances passing through the trachea and protects the lungs from them.

• The trachea’s inner layer has a small hair-like structure called cilia. These cilia are responsible for pushing the mucus out of the trachea, which can either be swallowed or expelled.

Where Is the Trachea Located?

A part of the trachea is in the neck region, and the other part lies in the upper chest region. It starts below the prominence seen in the neck. The esophagus, that is, the food pipe, lies posterior to it.

What Does Trachea Do?

The main function of the trachea is to allow the air to pass through it to the bronchi and, in turn to the lungs. The trachea forms the passageway for the air. Also, it prevents the entry of particles like dust, pollen, and other allergens into the lungs. Any obstruction or any disease affecting the trachea will lead to shortness of breath and could be serious.

What Conditions and Diseases Affect Trachea?

The following conditions can affect the trachea:

• Tracheal Stenosis- Tracheal stenosis is the condition in which there is an abnormal narrowing of the trachea, which makes it difficult for the passage of air through it. The patient will have wheezing, coughing, or shortness of breath in the tracheal stenosis condition. The treatment could include bronchoscopic tracheal dilatation, Argon plasma coagulation, bronchial artery embolization, or tracheobronchial airway stent.

• Tracheal Foreign Body- It is most common in children. This is a condition where a foreign body that is inhaled or aspirated gets lodged in the trachea. The symptoms could be choking followed by a protracted cough. To remove the foreign body from the trachea, bronchoscopy might be required.

• Tracheoesophageal Fistula- It is the channel formed between the trachea and the esophagus(food pipe). It could be caused by a blunt chest or neck trauma, prolonged mechanical ventilation by endotracheal or tracheostomy tube, or an iatrogenic injury. This can cause the passage of food from the esophagus to the lungs, which can cause serious infections.

• Tracheal Cancer- It is a very rare cancer that starts in the trachea. The symptoms could include coughing, shortness of breath, or wheezing. Surgeries might be needed for the treatment, along with which brachytherapy or photodynamic therapy might be required.

• Tracheomalacia- This is a condition in which the tracheal cartilages, rather than being firm, are soft which allows the tracheal wall to collapse and block the airway. One can have tracheomalacia by birth or could be caused by injury or smoking. The treatment would include chest therapy, speech and language therapy, or a tracheobronchial airway stent.

• Tracheal Obstruction- Any growth or tumor in the trachea can cause this condition. The symptoms of this condition will depend upon how severely the airway is blocked. The symptoms could be choking and struggling to breathe to turn blue. If it is severely blocked, it can even be fatal.

What Tests and Treatments Are Done for Tracheal Conditions?

The tests done to diagnose any condition related to trachea are:

• Flexible Bronchoscopy- An endoscope( a flexible tube with a camera and light fitted to it) is inserted into the nose or through the mouth to the trachea. With this procedure, we can visualize the inside of the trachea and the branches.

• Rigid Bronchoscopy- A rigid metal tube is inserted into the mouth to visualize the trachea. Rigid bronchoscopy is more useful than flexible bronchoscopy.

• CT (Computed Tomography) Scan- A CT scan enables one to visualize the structures in more detail. It takes a series of X-ray and is viewed on the computer. These tests could be advised to diagnose any obstruction or any tumor of the trachea.

• MRI (Magnetic Resonance Imaging) Scan- This technique uses radio waves in a magnetic field to visualize in detail the structures of the trachea and the adjacent structure.

• Chest X-ray- This could reveal the position of the trachea in the chest and also any foreign body entrapped within.

Trachea treatments include:

• Tracheostomy- A tracheostomy is an opening made in the anterior wall of the trachea so as to insert a tube into it to ease breathing. It can be done to bypass an obstructed upper airway, clear the secretions from the airway, or deliver oxygen more easily into the lungs. Tracheostomy is done for only high tracheal lesions.

• Tracheal Dilatation- It is done in case of tracheal stenosis to open the airways. In bronchoscopy, a balloon is inflated, which will open up the stenosis a bit.

• Tracheal Stenting- Tracheal stenting refers to the placement of a stent in the trachea to treat blocked airways. This is a minimally invasive procedure and is used mainly to relieve symptoms from cancer blocking the airways.

• Surgery- Surgery might be required to remove any growth or tumor in the trachea.

Conclusion

The trachea, also known as the windpipe, is a crucial component of the respiratory system. These have ‘C’ shaped cartilaginous rings to maintain the rigidity and hence, maintain the airways intact. The trachea connects the larynx to the lungs. The trachea divides into two bronchi which in turn enter the lungs. Any disease or condition that affects the trachea could be mild or severe depending upon what the cause is. But try to consult a medical practitioner immediately in such cases as early diagnosis can help in getting better treatment in most of the cases.