Pulmonary alveoli seen under the microscope
An alveolus (plural: alveoli, from Latin alveolus, “little cavity”) is an anatomical structure that has the form of a hollow cavity. Found in the lung parenchyma, the pulmonary alveoli are the terminal ends of the respiratory tree, which outcrop from either alveolar sacs or alveolar ducts, which are both sites of gas exchange with the blood as well.
Image by David Gregory and Debbie Marshall
Found on anatomybox.com
text source: Daily Anatomy