The trachea (trachea) is an organ of the respiratory system that provides air to the bronchial tree.
The superior border of the trachea in an adult is located at the level of the 6th cervical vertebra. This area corresponds to the level of the cricoid cartilage. The inferior border of the trachea is located at the level of the 5th thoracic vertebra, where it passes into the carina of the trachea (carina tracheae) and divides into the right and left main bronchi.
This area is called the tracheal bifurcation (bifurcatio tracheae)
According to some classifications , there are two parts of the trachea:
- Cervical trachea, which is located in the anterior cervical region
- Thoracic trachea, which passes in the mediastinum
The imaginary line drawn along the superior thoracic aperture serves as the border between these parts.
It is projected onto the anterior cervical region and the sternal region of the anterior thoracic wall.
On the sides of the organ, there is a neurovascular bundle, which includes the common carotid artery, the internal jugular vein and the vagus nerve.
The esophagus adheres to the trachea posteriorly. It borders the trachea along its entire length and is separated from its posterior wall by a thin layer of fiber tissue.
In the area of bifurcation, the trachea adheres to:
1. The arch of the aorta
2. The brachiocephalic trunk and brachiocephalic vein
3. The left common carotid artery
Anteriorly to the trachea, the following structures are located:
- Suprasternal space
- Interaponeurotic space
- Paratracheal space, where the lymph nodes, vagus nerve, and branches of the sympathetic nerve trunk, as well as the thoracic duct, are located
- The pretracheal space, where the unpaired thyroid venous plexus and sometimes an additional branch of the aorta lie
In trachea, there are the cartilaginous part
And the membranous part
The cartilaginous part consists of 16-20 cartilaginous semi-rings. The cartilages of the trachea are not closed along the posterior surface and are connected by a thin mobile membrane, which is the membranous part of the organ. In addition to connective tissue, the membrane contains bundles of myocytes.
Above and below the rings are connected by the anular ligaments (lig. anulare)
The mucous membrane of the trachea contains a large number of cilia that push mucus from the trachea to the upper respiratory tract. It is worth noting that mucus is produced in large quantities. The largest cluster of glands is located in the area of the bifurcation.
Several arteries supply the trachea with blood, including the inferior thyroid artery, internal thoracic artery, as well as the bronchial branches of the thoracic aorta, which also supply the bronchi with blood.
Venous blood flows to the venous plexuses in the circumference of the trachea, thyroid gland and bronchi.
The lymphatic vessels of the trachea carry lymph to the nearest paratracheal and paravertebral lymph nodes, as well as the nodes of the bifurcation. The lymphatic vessels of the bronchi pass to the peribronchial lymph nodes.
The trachea and bronchi are innervated directly by the vagus nerve and its branch called the inferior laryngeal nerve, as well as the nerves that arise from the sympathetic trunk.
Anatomy of the trachea
- Bronchial tree
- arbor bronchialis
- Carina of the trachea
- carina tracheae
- Tracheal bifurcation
- bifurcatio tracheae