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Airway Struclure: Trachea and Major Bronchi

RESPIRATORY PHYSIOLOGY

Thyroid cartilage -Cricothyroid ligament -Cricoid cartilage-

Connective tissue sheath Cartilage

Elastic fibers Gland

Smali artery

Lymph ves$el$ Nerve

pithelium

Connective tissue sheath <cut away)

Cross section through trachea

Postcrior wali

Tracheal cartilages

Mucosa showing longitudinal folds tormcd by dense collections of elastic fibers

Epartcrial

bronchus

Nerve

Smali arteries | Gland

| Tachealis musde Esophageal musde Epithelium

Elastic fibers Lymph vessels

uppcr

lobe

To

middle

lobe

bronchus bronchus

Intrapulmonary    Extrapulmonary

Figurę 5.2 Structure of the Trachea and Major Bronchi

The major conducting airways to the lungs indude the cartilaginous tiachea, the right and Icft main bronchus, and the intrapulmonary bronchi passing through the lung parenchyma. Wilh each subse-quent branching, the conducting airways become smaller and smaller in diameter <see Figurę 5.3), eventually losing their cartilagi-nous plates.

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