Final answer:
The epithelial tissue found in both alveolar and endothelial tissue is the simple squamous epithelium, which facilitates the exchange of gases in the lungs and minimizes resistance to blood flow in the blood vessels.
Step-by-step explanation:
The type of epithelial tissue found in both alveolar and endothelial tissue is the simple squamous epithelium.
This type of epithelium is characterized by a single layer of flat cells that facilitate the exchange of gases and other substances.
In the lungs, the alveolar tissue allows for the diffusion of oxygen and carbon dioxide between the air spaces and the blood.
The endothelial tissue, lining the blood vessels, provides a smooth surface that minimizes resistance to blood flow and also participates in material exchange.