alveolus

(noun)

a small air sac in the lungs, where oxygen and carbon dioxide are exchanged with the blood

Related Terms

Examples of alveolus in the following topics:

  • Alveoli

    • An alveolus is an anatomical structure that has the form of a hollow cavity.
    • Its plural is alveoli, from the Latin alveolus, meaning little cavity.
    • In some alveolar walls there are pores between alveoli called the pores of Kohn, that connect alveoli in order to equalize air pressure between the different sacs of an alveolus.

  • Inspiration

    • Inhalation is the flow of air into an organism which is generated due to pressure difference between the atmosphere and alveolus.

  • Blood Flow in the Lungs

  • Chromalveolata: Alveolates

    • Alveolates are defined by the presence of an alveolus beneath the cell membrane and include dinoflagellates, apicomplexans and ciliates.
    • The alveolates are named for the presence of an alveolus, or membrane-enclosed sac, beneath the cell membrane.
    • The exact function of the alveolus is unknown, but it may be involved in osmoregulation.

  • Carbon Dioxide Transport

    • After carbon dioxide travels through the bloodstream to the capillaries covering the alveoli of the lungs through any of the 3 methods listed above, it must return to dissolved carbon dioxide form in order to diffuse across the capillary into the alveolus. 
    • Dissolved carbon dioxide is already able to diffuse into the alveolus, while hemoglobin-bound carbon dioxide is unloaded into the plasma.
    • The dissolved carbon dioxide is then able to diffuse into the alveolus.

  • Fetal Circulation

    • Oxygen then diffuses from the placenta to the chorionic villus, an alveolus-like structure, from which it is carried to the umbilical vein.

  • Basic Principles of Gas Exchange

    • This illustrates the exchange of gas in humans between a capillary and an alveolus.

  • External Respiration

  • Bronchi and Subdivisions

    • The alveolus is the smallest anatomical unit of the lung, and the site of gas exchange between the lung and the bloodstream.

  • Mammalian Systems and Protective Mechanisms

    • Numerous alveoli (sing. alveolus) and alveolar sacs surround the alveolar ducts .