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Respiratory Structure
apex -
larynx thoracic cavity
trachea + lungs
ribs
bronchi -
O
lobes
OOOTIT
BSYON
diaphragm (while
breathing out) heart
diaphragm (while
breathing in) Inner structure of the lungs The inner structure of the lungs resembles a tree in which the main trunk is the trachea, the branches are the bronchi and bronchioles, and the leaves the alveoli.
Trachea: The trachea is the windpipe connected to the larynx at the base of the throat. It is a tube formed from cartilaginous rings and muscle tissue, which keep it constantly open. The trachea is lined with tiny hairs called cilia, which have an upward sweeping movement that stops dust, pollen and other minute foreign objects from entering the lungs.
Bronchi-. The lower end of the trachea branches into the left and right principal bronchi. The bronchi further divide, like the branches of an upside-down tree, into smaller bronchioles, which traverse the lungs. The larger bronchi retain cartilage and small, smooth muscles, which prevent them from closing, as in the trachea. However, as these bronchial lubes become smaller, the cartilage disappears, leaving only
a fibrous muscular coat and the ciliated mucous lining.
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