Alveolar duct

By Shoummojit Roy on June 9, 2012 in Respiratory System

Alveolar duct Definition

It refers to very small end ducts of the ramifying airways inside the lungs. There are approximately 1.5-2 million such structures within each lung of a person. These are also often known as the final branches of the human bronchial tree.

Alveolar duct Location

As aforementioned, these are located inside the lungs. These are found beyond the respiratory bronchioles. These are formed by a series of alveoli lying next to each other.

Alveolar duct Function

This is a part of the human respiratory passage branching out from the bronchioles. The alveoli and the alveolar sacs originate from this structure. It serves as the connection between the bronchi and the alveoli.

The functions have been jotted down in short:

Alveolar ducts assist alveoli in handling proper gas exchange as and when air arrives in a specific volume and at a certain pressure
The ducts collect the air inhaled and moved through the tract and thereby transport it to the alveoli
As soon as the gas has been exchanged by the alveoli, the ducts carry the carbon dioxide to be exhaled
By collecting the exhaled carbon dioxide, the alveolar ducts allow the air pressure to be exerted in the lungs that help more air to be exhaled at a time.

Alveolar Duct Clinical Relevance

The alveolar ducts and alveoli serve to be the sites that are involved in several infections. They may cause Pneumonia. These structures are present on the parenchyma of the lungs and hence they show huge involvement in the blockage of a pulmonary artery, which is referred to as pulmonary embolism.

There is a capillary bed that surrounds the alveoli. This bed is prone to get damaged and thereby lead to the leakage of fluid via alveolar capillaries. As a result, the fluid gets accumulated in the lungs, which causes pulmonary edema. Another condition that marks the damage of the capillary bed is acute respiratory distress syndrome.