Anatomy of the trachea and broncheal tree. By; Dr. Eman Abdelghany Assistant Prof. of Anatomy & Embryology Al-Qassim university. Anatomy of the trachea. Length : 10 cm Width : 2 cm Begins: as a continuation of larynx, at lower border of cricoid cartilage (C6).
Dr. Eman Abdelghany
Assistant Prof. of Anatomy & Embryology
Length:10 cm Width: 2 cm
Begins: as a continuation of larynx, at lower border of cricoid cartilage (C6).
Ends:by dividing into two main bronchi opposite the disc between 4th & 5th thoracic vertebrae. It lies in midline of neck in front of esophagus and behind thyroid gland. Upper1\2 in the neck called cervical part, and Lower 1\2 in the thorax(in superior mediastinum) called thoracic part, It shows slight deviation to the right.
15-20 incomplete cartilaginous rings (C –shaped)-completed by trachealis muscle posteriorly.
Becomes intra-thoracic at 6th cartilaginous ring
The last tracheal ring is Y- shaped called the carina. The Carinais the site of branching to left and right primary bronchi , at the tracheal bifurcation.
The posterior wall is trachealis muscle which, allows esophageal expansion during deglutition
A highly branched system , The air-conducting passages
originate from the left and right primary bronchi.
Progressively branch into narrower tubes as they diverge throughout the lungs before terminating into terminal bronchioles.
-Incomplete rings of hyaline cartilage ensure that they remain open.Theyenter the hilum of each lung.
Right primary bronchus is, shorter, wider, and more vertically oriented than the left primary bronchus.
Foreign particles are more likely to lodge in the right primary bronchus
Secondary bronchi (or lobar bronchi)
2 secondary bronchi
3 secondary bronchi.
Tertiary bronchi (or segmental bronchi)
-well defined sectors of lung.
-each segment is surrounded by connective tissue and forms a separate respiratory unit .
-shape: pyramidal with apex at the hilum and the base towards surface of lung.
Med. Basal ,small. May arise by common stem with ant. basal