Tracheobrachial Flashcards
what forms the tracheobronchial tree?
The trachea, bronchi and bronchioles
what is the tracheaobrachial tree and where is it found
a system of airways that allow passage of air into the lungs, where gas exchange occurs. These airways are located in the neck and thorax.
anterior position of the trachea
The trachea marks the beginning of the tracheobronchial tree. It arises at the lower border of cricoid cartilage in the neck, as a continuation of the larynx.
It travels inferiorly into the superior mediastinum, bifurcating at the level of the sternal angle (forming the right and left main bronchi). As it descends, the trachea is located anteriorly to the oesophagus, and inclines slightly to the right.
structure of the trachea
The trachea, like all of the larger respiratory airways, is held open by cartilage – here in C-shaped rings. The free ends of these rings are supported by the trachealis muscle.
The trachea and bronchi are lined by ciliated pseudostratified columnar epithelium, interspersed by goblet cells, which produce mucus. The combination of sweeping movements by the cilia and mucus from the goblet cells forms the functional mucociliary escalator. This acts to trap inhaled particles and pathogens, moving them up out of the airways to be swallowed and destroyed.
At the bifurcation of the primary bronchi, a ridge of cartilage called the carina runs anteroposteriorly between the openings of the two bronchi. This is the most sensitive area of the trachea for triggering the cough reflex, and can be seen on bronchoscopy.
nerve innervation of the trachea
the trachea receives sensory innervation from the recurrent laryngeal nerve.
arterial supply of the trechea
from the tracheal branches of the inferior thyroid artery
venous drainage of the trachea
venous drainage is via the brachiocephalic, azygos and accessory hemiazygos veins
innervation of the bronchi
pulmonary branches of the vagus nerve (CN X)
blood supply of the bronchi
Blood supply to the bronchi is from branches of the bronchial arteries,
veinous drainae of the bronchi
is into the bronchial veins.
when does the trachea birificate
T4 At the level of the sternal angle, the trachea bifurcates into the right and left main bronchi
what does each secondary bronchi supply
a lobe of lung
what makes up theroots of the lungs
Along with branches of the pulmonary artery and veins, the main bronchi make up the roots of the lungs.
structuree of teh bronchi
Right main bronchus – wider, shorter, and descends more vertically than its left-sided counterpart. Clinically, this results in a higher incidence of foreign body inhalation. The right superior lobar bronchus arises before the right main bronchus enters the hilum.
Left main bronchus – passes inferiorly to the arch of the aorta, and anteriorly to the thoracic aorta and oesophagus in order to reach the hilum of the left lung.
Within the lungs, the main (primary) bronchi branch into lobar (secondary) bronchi. Each secondary bronchi supplies a lobe of the lung, thus there are 3 right lobar bronchi and 2 left. The lobar bronchi then bifurcate into several segmental (tertiary) bronchi, each of which supplies a bronchopulmonary segment. Bronchopulmonary segments are subdivisions of the lung lobes, and act as the functional unit of the lungs.
The structure of bronchi are very similar to that of the trachea, though differences are seen in the shape of their cartilage. In the main bronchi, cartilage rings completely encircle the lumen. However in the smaller lobar and segmental bronchi cartilage is found only in crescent shapes.
trachea to left and right bronchi to secondary bronchi to segmental bronchi to what
bronchioles
