The Anatomy of the Trachea

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The trachea, commonly known as the windpipe, is the large tube that delivers air from the upper respiratory tract (the nasal passages, throat, and larynx) to the bronchi (the two large airways that branch off into each lung). In the process, it warms and moisturizes the air and catches debris and microbes before they enter the lungs.

The trachea can become infected, inflamed, or damaged. In rare situations, this can lead to tracheal stenosis, in which the trachea narrows and restricts breathing. Tracheal cancer is an extremely rare form of cancer.


The trachea is part of the lower respiratory tract, along with the lungs, bronchi, bronchioles, and alveoli.

Human Respiratory System Lungs Anatomy
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In an adult, the trachea is roughly 4 to 5 inches long and 1 inch in diameter. It starts just under the larynx (voice box) and runs down the center of the chest behind the sternum (breast bone) and in front of the esophagus.

The trachea is connected to the larynx via a ring of cartilage known as the cricoid cartilage. As the trachea descends the chest, it is surrounded by 16 to 22 U-shaped rings of cartilage that hold the windpipe open like scaffolding, allowing the flow of air.

The posterior wall of the trachea is not covered by cartilage and is composed of connective tissue and smooth muscle. The muscle will flex and expand when needed, to change the diameter of the trachea.

The trachea ends at the carina, a ridge of cartilage that separates and forms the junction into the bronchi.

Membrane Composition

Lining the trachea are mucosal membranes comprised of epithelial cells, mucus-secreting goblet cells, and hair-like projections called cilia that move foreign particles up and out of the airway.

Within these membranes are submucosal glands, which act as companions to goblet cells by secreting water molecules and mucin (the gel-like component of mucus) onto the tracheal lining.

The trachea is traversed by a network of blood vessels and lymphatic vessels. Blood vessels provide the tissues with oxygen and nutrients and regulate the exchange of heat within the airway. The lymphatic vessels help remove infectious microbes on the surface of the wall of the trachea so they can be isolated and neutralized by the immune system.


The trachea serves as the main passageway through which air passes from the upper respiratory tract to the lungs. As air flows into the trachea during inhalation, it is warmed and moisturized before entering the lungs.

Most particles that enter the airway are trapped in the thin layer of mucus on the trachea walls. These are then moved upwards toward the mouth by cilia, where they can be coughed up or swallowed.

The U-shaped sections of cartilage that line the trachea are flexible and can close and open slightly as the trachealis muscle at the back of the rings contracts and relaxes. Subtle contractions of the trachea occur involuntarily as part of normal respiration.

If any object, liquid, or irritant (like smoke) enters the trachea, the muscles can contract violently, causing coughing to expel the substance.

Contractions can be voluntary as well, as with controlled coughing, which is used to clear the airways in people with chronic obstructive pulmonary disease (COPD) or cystic fibrosis.

Associated Conditions 

The trachea, like all parts of the respiratory system, is vulnerable to inhaled substances that can damage tissue and interfere with breathing. Certain infections and diseases can also affect the trachea.


Coughing is the body's way to remove foreign substances from the throat, trachea, or lungs. If an object cannot be dislodged from the trachea, choking can occur. Severe choking can prevent oxygen from getting into the lungs, which may lead to syncope (fainting), asphyxiation (suffocation), or death.

Emergency interventions, such as the Heimlich maneuver or a tracheostomy, may be needed to clear the trachea of an obstruction. Non-life-threatening obstructions can be treated with bronchoscopy, in which a flexible scope is inserted into the throat to locate and remove foreign objects.


Tracheitis is inflammation of the trachea. It occurs almost exclusively in children. It is most often associated with a bacterial infection that has spread from the upper respiratory tract. The bacteria Staphylococcus aureus is a common culprit.

Tracheitis is especially worrisome in babies and young children because any inflammation of their small windpipes can lead to blockage and, in some cases, asphyxiation.

Stridor (high-pitched wheezing caused by airway obstruction or restriction) is a common symptom of tracheitis. Croup, laryngotracheobronchitis, an inflammatory/infectious condition that can progress to airway obstruction, can occur as well.

Bacterial tracheitis is typically treated with antibiotics. Severe cases may require intravenous antibiotics as well as intubation and mechanical ventilation to aid with breathing.

Tracheoesophageal Fistula

A tracheoesophageal fistula is an abnormal passageway between the trachea and the esophagus that allows swallowed food to enter the trachea and, from there, the lungs. This can lead to choking, gagging, breathing difficulty, and cyanosis (bluish skin due to the lack of oxygen). Aspiration pneumonia can also occur.

A transesophageal fistula is rare and may occur due to trauma, cancer, or a congenital defect that causes the incomplete formation of the esophagus (known as esophageal atresia).

Roughly one of every 4,000 children in the United States is born with a tracheoesophageal fistula. In most cases, it can be treated with surgery.

Tracheal Stenosis

Whenever the trachea is damaged, scarring can develop and cause tracheal stenosis (airway narrowing).

Tracheal stenosis can cause stridor and dyspnea (shortness of breath), especially with physical exertion.

Causes of tracheal stenosis include:

  • Goiter
  • Sarcoidosis
  • Amyloidosis
  • Diphtheria and other severe respiratory infections
  • Wegener's granulomatosis
  • Thyroid cancer
  • Lung cancer
  • Lymphoma of the chest

Between 1% and 2% of people who undergo intubation and mechanical ventilation will develop tracheal stenosis. People who require prolonged ventilation are at greatest risk.

Stenosis may be treated with stents and tracheal dilation. In severe cases, surgery may be required.


Tracheomalacia is an uncommon condition in which the trachea collapses on itself during breathing and with coughing. It often is a result of prolonged intubation. It is also a complication of COPD, caused by the progressive deterioration of tracheal cartilage caused by chronic inflammation and coughing.

Tracheomalacia can also affect newborns as a result of congenital weakness of tracheal cartilage. Symptoms include stridor, rattling breath sounds, and cyanosis.

  • Acquired tracheomalacia may require surgery to correct and support the weakened airway.
  • Congenital tracheomalacia rarely requires surgery and usually resolves on its own by the time the child is 2.

Tracheal Cancer

Tracheal cancer is extremely rare, occurring at a rate of approximately one case per every 500,000 people. Most are squamous cell carcinomas caused by cigarette smoking. Cancers that originate in nearby structures, such as the lungs, esophagus, or thyroid gland, can sometimes metastasize (spread) to the trachea.

Benign tumors, including chondromas and papillomas, can also develop in the trachea. Though benign, these can block airways, affect breathing, and trigger stenosis.

The surgical removal of a tracheal tumor is the preferred method of treatment (with or without radiation therapy). Some people may be able to be treated with radiation alone. Chemotherapy with radiation often is used if a tumor cannot be removed.

Treatment and Rehabilitation

Injuries, infections, and diseases of the trachea can cause damage to the airway, sometimes irreparably. Tracheal stenosis is one such case in which the development of fibrosis (scarring) is most often permanent. Once the underlying cause of a tracheal injury is treated, efforts may be made to repair the trachea or support its function.

Chest Physical Therapy

Since most children with tracheomalacia outgrow the condition by the age of 3, treatment efforts will usually be supportive. This includes chest physical therapy (CPT) to maintain proper airway clearance.

Techniques involve chest percussion, vibration/oscillation, deep breathing, and controlled coughing. A humidifier and continuous positive airway pressure (CPAP) device may also be recommended.

CPT also may be recommended for adults with tracheomalacia or anyone who experiences chronic airway obstruction or restriction. Regular exercise, 20 to 30 minutes five times weekly, can also help.

Tracheal Dilation and Stent Placement

In certain cases of tracheal stenosis, a flexible, tube-like instrument called a bougienage may be inserted into the trachea during a bronchoscopy and expanded with a balloon to dilate the airway. A rigid silicone or metal sleeve, called a stent, is then inserted to hold the trachea open.

Tracheal dilation and stent placement are typically used when surgery isn't possible. Most procedures can be done on an outpatient basis and only require a short-acting anesthetic like propofol.

Ablation Therapy

Stenosis can often be treated by destroying retracted scar tissue that narrows the airway. The procedure, called ablation, can release the retracted tissue and improve breathing.

Ablative techniques include laser therapy (using a narrow beam of light), electrocautery (using electricity), cryotherapy (using cold), brachytherapy (using radiation), and argon plasma (using argon gas).

Ablation therapies usually can be performed on an outpatient basis with a mild, short-acting sedative and tend to be successful, although pain, cough, and infection are possible.

Fistula Repair

Tracheoesophageal fistulas almost always require surgical repair to close the hole between the trachea and the esophagus. Although tracheal stenting is sometimes used to plug the gap, the stent can slip and require repositioning or replacement.

Surgery is a more permanent solution. Once the hole is repaired with sutures, a full-thickness skin graft or muscle graft may be used to prevent the reopening of the fistula.

The rate of complications following fistula repair surgery is high—between 32% and 56%. Pneumonia, airway obstruction, wound infection, and reopening of the fistula are the most common complications.

Tracheal Resection

Tracheal resection and reconstruction (TRR) is an open surgical procedure commonly used to remove tracheal tumors and treat severe post-intubation stenosis or fistulas.

This procedure involves removal of a section of the airway, the cut ends of which are then stitched together with sutures. Reconstruction involves placement of a small piece of cartilage (taken from another part of the body) to rebuild the trachea and keep it well supported.

TRR is considered major surgery and typically requires two to three weeks of recovery. Complications include post-operative stenosis or fistula as well as vocal cord dysfunction.

Tracheal Reconstruction

Techniques such as the Maddern procedure and the REACHER technique are sometimes used to treat stenosis in the upper part of the trachea near the larynx.

These procedures involve removal of diseased tissue combined with a full-thickness skin graft from the thigh.

  • The Maddern procedure can be performed transorally (through the mouth).
  • The REACHER procedure requires a cervicotomy, is faster than a resection, and has a far shorter recovery time.

Not all surgeons use these techniques. To this end, you may need to seek treatment outside of your immediate area with a specialist ENT-otolaryngologist if one of these approaches is recommended for your condition.


Tracheostomy and tracheotomy are surgical procedures in which a breathing tube is inserted into the trachea through an incision in the throat.

  • Tracheostomy is a permanent opening in the trachea. It may be used for laryngectomy patients, laryngeal stenosis, and crushing laryngeal injuries. This may also be needed for people with a major spinal cord injury who cannot breathe adequately on their own or those with end-stage lung disease.
  • Tracheotomy is a temporary opening into the trachea. A traumatic chest wall injury or epiglottitis may require an emergency tracheotomy. This may also be needed for head and neck cancer patients undergoing radical resections and reconstructions.

These procedures may be used when intubation through the nose or mouth is not possible or when long-term ventilator support is needed.

Frequently Asked Questions

  • What is the main function of the trachea?

    The trachea is a passageway for air from the upper respiratory tract to the lungs. Air that enters the trachea is warmed and moisturized before moving on to the lungs. Mucus on the trachea walls can catch debris or particles. This debris is then transported upward by cilia, tiny hair-like structures that remove it from the airway.

  • What type of tissue lines the trachea?

    Mucosal membranes are the tissues that line the trachea. These tissues are made of epithelial cells that produce mucus to capture debris before it can reach the lungs. Inside the mucosal membranes are submucosal glands, which secrete water and mucin, the components of mucus.

  • What is the carina?

    The carina is a tube of cartilage that forms the end of the trachea. It splits off into the left bronchus and the right bronchus, which lead to each of the lungs.

  • What causes an incomplete expansion of the lung?

    Atelectasis is a condition that causes an incomplete expansion of the lung. It can occur if an airway is blocked, the lungs have pressure applied to them, or if there is a low amount of surfactant in the lungs. Surfactant is a foamy substance that helps keep air sacs open.

21 Sources
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  1. Furlow P, Mathisen D. Surgical anatomy of the trachea. Annals Cardiothoracic Surgery. 2018;7(2):255-60. doi:10.21037/acs.2018.03.01

  2. Widdicombe JH. Early studies of airway submucosal glands. Am J Physiol Lung Cell Mol Physiol. 2019;316(6):L990-L998. doi:10.1152/ajplung.00068.2019

  3. McDonald DM, Yao LC, Baluk P. Dynamics of airway blood vessels and lymphatics: lessons from development and inflammationProc Am Thorac Soc. 2011;8(6):504-7. doi:10.1513/pats.201102-022MW

  4. Polverino M, Polverino F, Fasolino M, et al. Anatomy and neuro-pathophysiology of the cough reflex arcMultidiscip Respir Med. 2012;7:5. doi:10.1186/2049-6958-7-5

  5. Duckett SA, Roten RA. Choking. In: StatPearls.

  6. Kuo CY, Parikh SJ. Bacterial tracheitis. Pediatric Rev. 2014 Nov:35(11):497-9. doi:10.1542/pir.35-11-497

  7. American Pediatric Surgical Association. Esophageal atresia and tracheo-esophageal fistula (EA and TEF).

  8. Motus I, Nadezhda G. Tracheal stenosis: Prevention and treatment. Eur Respir J. 2013;42 (Suppl_7):P4955.

  9. Liu J, Zhang CP, Li Y, Dong S. Post-intubation tracheal stenosis after management of complicated aortic dissection: a case seriesJ Cardiothorac Surg. 2015;10:148. doi:10.1186/s13019-015-0357-z

  10. Kerolus G, Ikladios O. Tracheomalacia and recurrent exacerbations of chronic obstructive pulmonary disease: a case report and review of the literatureJ Community Hosp Intern Med Perspect. 2016;6(6):33540. doi:10.3402/jchimp.v6.33540

  11. Kurada S, Karthikeyan RB, Vakamudi M, Thangavelu P. Management of tracheomalacia in an infant with Tetralogy of FallotIndian J Anaesth. 2015;59(4):240-3. doi:10.4103/0019-5049.155002

  12. Napieralska A, Miszczyk L, Blamek S. Tracheal cancer - treatment results, prognostic factors and incidence of other neoplasmsRadiol Oncol. 2016;50(4):409-17. doi:10.1515/raon-2016-0046

  13. López-Padilla D, García-Luján R, Puente Maestu L, De Miguel Poch E. Tracheobronchomalacia treatment: How far have we come?. J Thorac Dis. 2016;8(12):3490-3. doi:10.21037/jtd.2016.12.91

  14. Bacon JL, Patterson CM, Madden BP. Indications and interventional options for non-resectable tracheal stenosisJ Thorac Dis. 2014;6(3):258-70. doi:10.3978/j.issn.2072-1439.2013.11.08

  15. Bibas BJ, Cardoso PFG, Minamoto H, Pêgo-Fernandes PM. Surgery for intrathoracic tracheoesophageal and bronchoesophageal fistulaAnn Transl Med. 2018;6(11):210. doi:10.21037/atm.2018.05.25

  16. Auchincloss HG, Wright CD. Complications after tracheal resection and reconstruction: prevention and treatmentJ Thorac Dis. 2016;8(Suppl 2):S160-S167. doi:10.3978/j.issn.2072-1439.2016.01.86

  17. Daniero JJ, Ekbom DC, Gelbard A, Akst LM, Hillel AT. Inaugural symposium on advanced surgical techniques in adult airway reconstruction: Proceedings of the North American Airway Collaborative (NoAAC)JAMA Otolaryngol Head Neck Surg. 2017;143(6):609-13. doi:10.1001/jamaoto.2016.4126

  18. Cheung NH, Napolitano LM. Tracheostomy: Epidemiology, indications, timing, technique, and outcomes. Respir Care. 2014;59(6):895-915. doi:10.4187/respcare.02971

  19. MedlinePlus. Respiratory cilia.

  20. MedlinePlus. Epithelial cells.

  21. National Heart, Lung, and Blood Institute (NHLBI). Atelectasis.

By Lynne Eldridge, MD
 Lynne Eldrige, MD, is a lung cancer physician, patient advocate, and award-winning author of "Avoiding Cancer One Day at a Time."