Larynx, hypopharynx & trachea


Anatomy & histology-trachea

Topic Completed: 1 October 2012

Minor changes: 2 March 2021

Copyright: 2002-2021,, Inc.

PubMed Search: Trachea histology [title]

Adriana Handra-Luca, M.D., Ph.D.
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Cite this page: Handra-Luca A. Anatomy & histology-trachea. website. Accessed December 3rd, 2021.
Definition / general
  • Composed of imperfect rings of hyaline cartilage, fibrous tissue, muscular fibers, mucous membranes and glands
  • Cartilaginous and membranous tube (also called windpipe), extending from lower larynx at C6 to upper border of T5 vertebrae, where it divides into right and left mainstem bronchi
  • Flattened posteriorly
  • 11 cm long, 2 - 2.5 cm in diameter, diameter greater in men than women, greater in adults than children
  • Anteriorly: contacts thyroid isthmus, inferior thyroid veins, neck muscles, cervical fascia, anterior jugular veins, manubrium sterni, thymus, left innominate vein, aortic arch, innominate and left common carotid arteries, deep cardiac plexus
  • Posteriorly: contacts esophagus
  • Right bronchus appears to be a more direct continuation of trachea and so is the site of most foreign bodies
  • Supplied by inferior thyroid arteries
  • 16 - 20 imperfect rings, with circular cartilaginous defect posterior and replaced by fibrous tissue and muscular fibers
  • Each cartilage is 4 mm in depth, 1 mm in thickness
  • Are elastic but may be calcified later in life

Fibrous tissue:
  • Thick layer covers outer surface of cartilaginous ring, thin layer covers inner surface
  • Both layers merge at upper and lower margins of cartilaginous rings

Muscular tissue:
  • Longitudinal and transverse layers of smooth muscle

Mucus membrane:
  • Continuous with laryngeal and bronchial membranes
  • Ciliated columnar epithelium overlying areolar and lymphoid tissue with elastic fibers, blood vessels, nerves, mucous glands
Diagrams / tables

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Trachea and bronchi

Tracheal bifurcation

Transverse section

Microscopic (histologic) images

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Transverse section

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