The trachea

The trachea - Inside the lungs, each primary bronchus...

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The trachea (windpipe) is a flexible tube, 10 to 12 cm (4 inches) long and 2.5 cm  (1 inch) in diameter (Figure 2).  The mucosa is the inner layer of the trachea. It contains mucus-producing goblet  cells and pseudostratified ciliated epithelium. The movement of the cilia sweeps  debris away from the lungs toward the pharynx. The submucosa is a layer of areolar connective tissue that surrounds the  mucosa. Hyaline cartilage forms 16 to 20 C-shaped rings that wrap around the  submucosa. The rigid rings prevent the trachea from collapsing during inspiration. The adventitia is the outermost layer of the trachea. It consists of areolar  connective tissue. The primary bronchi are two tubes that branch from the trachea to the left and  right lungs.
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Unformatted text preview: Inside the lungs, each primary bronchus divides repeatedly into branches of smaller diameters, forming secondary (lobar) bronchi, tertiary (segmental) bronchi, and numerous orders of bronchioles (1 mm or less in diameter), including terminal bronchioles (0.5 mm in diameter) and microscopic respiratory bronchioles. The wall of the primary bronchi is constructed like the trachea, but as the branches of the tree get smaller, the cartilaginous rings and the mucosa are replaced by smooth muscle. Alveolar ducts are the final branches of the bronchial tree. Each alveolar duct has enlarged, bubblelike swellings along its length. Each swelling is called an alveolus. Some adjacent alveoli are connected by alveolar pores....
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This note was uploaded on 11/10/2011 for the course PT 101 taught by Professor Staff during the Spring '10 term at Texas State.

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