alveolus

American  

[al-vee-uh-luhs] / ælˈvi ə ləs /

noun

• alveoli
  plural

1. a little cavity, pit, or cell, as a cell of a honeycomb.

2. an air cell of the lungs, formed by the terminal dilation of tiny air passageways.

3. one of the terminal secretory units of a racemose gland.

4. the socket within the jawbone in which the root or roots of a tooth are set.

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alveolus British  

/ ælˈvɪələs /

noun

1. any small pit, cavity, or saclike dilation, such as a honeycomb cell

2. any of the sockets in which the roots of the teeth are embedded

3. any of the tiny air sacs in the lungs at the end of the bronchioles, through which oxygen is taken into the blood

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alveolus Scientific  

/ ăl-vē′ə-ləs /

• alveoli
  plural

1. Any of the tiny air-filled sacs arranged in clusters in the lungs, in which the exchange of oxygen and carbon dioxide takes place.

2. Also called air sac

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Other Word Forms

Noun Inflected Forms

• alveoli
  plural

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Etymology

Origin of alveolus

1700–10; < Latin, equivalent to alve ( us ) concave vessel + -olus -ole ¹

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Example Sentences

See Examples For:

alveolus alveoli

In one example, six nests were stacked within a single alveolus, arranged one inside another like Russian dolls.

From Science Daily ● Apr. 3, 2026

A focus-stacked picture of a tiny, 3D-printed alveolus, or artificial lung.

From Science Magazine ● Dec. 16, 2019

As oxygen diffuses across the respiratory membrane from the alveolus to the capillary, it also diffuses into the red blood cell and is bound by hemoglobin.

From Textbooks ● Jun. 19, 2013

Figure 22.22 External Respiration In external respiration, oxygen diffuses across the respiratory membrane from the alveolus to the capillary, whereas carbon dioxide diffuses out of the capillary into the alveolus.

From Textbooks ● Jun. 19, 2013

Alveolobasilar length.—from the posterior border of the alveolus of the third upper molar to the posterior border of the alveolus of the incisor.

From Subspeciation in the Meadow Mouse, Microtus montanus, in Wyoming and Colorado by Sydney Anderson

Microscopic analysis of tissue from sick cows showed the virus infects cells in the alveoli, the millions of tiny milk-producing sacs in udders.

From Science Magazine ● Apr. 30, 2024

Sand is fine enough that it can travel deep into the lungs, blocking off access to the alveoli, which is where the lungs hand off their oxygen to the blood.

From Slate ● Mar. 1, 2024

"We have identified a key metabolic relationship between macrophages and alveoli that is exploited by tumor cells to support the cancer's metabolic demands -- now we just have to disrupt that exploitation."

From Science Daily ● Feb. 7, 2024

Lungs rely on tiny bulbs called alveoli, which expand and deflate with our breath, to facilitate the exchange of oxygen and carbon dioxide between the air and our blood.

From Science Daily ● Feb. 7, 2024

This starts at the right ventricle and by its branches conveys blood to the capillaries surrounding the alveoli in all parts of the lungs.

From Physiology and Hygiene for Secondary Schools by Francis M. Walters

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