Search results
Results from the WOW.Com Content Network
The bronchioles (/ ˈ b r ɑː ŋ k i oʊ l s / BRONG-kee-ohls) are the smaller branches of the bronchial airways in the lower respiratory tract.They include the terminal bronchioles, and finally the respiratory bronchioles that mark the start of the respiratory zone delivering air to the gas exchanging units of the alveoli.
These enter the lungs where they branch into progressively narrower secondary and tertiary bronchi that branch into numerous smaller tubes, the bronchioles. In birds, the bronchioles are termed parabronchi. It is the bronchioles, or parabronchi that generally open into the microscopic alveoli in mammals and atria in birds.
The lower respiratory tract or lower airway is derived from the developing foregut and consists of the trachea, bronchi (primary, secondary and tertiary), bronchioles (including terminal and respiratory), and lungs (including alveoli). [7] It also sometimes includes the larynx.
The secondary bronchi divide further into tertiary bronchi, (also known as segmental bronchi), each of which supplies a bronchopulmonary segment. A bronchopulmonary segment is a division of a lung separated from the rest of the lung by a septum of connective tissue .
The secondary pulmonary lobule is likely to be made up of between 30 and 50 primary lobules. [30] The lobule is supplied by a terminal bronchiole that branches into respiratory bronchioles. The respiratory bronchioles supply the alveoli in each acinus and is accompanied by a pulmonary artery branch. Each lobule is enclosed by an interlobular ...
The classification of primary, secondary, and tertiary sources can be different in various disciplines and may depend on the context in which the source is used. The examples and definitions given in these guidelines are provided as an aid for more informed discussion of these classification issues when they come up.
The lung bud branches into two lateral outgrowths known as the bronchial buds, one on each side of the trachea. The right and left bronchial buds branch into main (primary), lobar (secondary), segmental (tertiary), and subsegmental bronchi and lead to the development of the lungs. [2]
A bronchopulmonary segment is a portion of lung supplied by a specific segmental bronchus and its vessels. [1] [2] These arteries branch from the pulmonary and bronchial arteries, and run together through the center of the segment.