no answer choices so i’m just gone put this. Gas exchange occurs only in alveoli. Alveoli are made of thin-walled parenchymal cells, typically one-cell thick, that look like tiny bubbles within the sacs. Alveoli are in direct contact with capillaries (one-cell thick) of the circulatory system
The epithelium that is found in places where diffusion of respiratory gases occurs is simple squamous.
Types of tissue:
There are 4 basic types of tissue: connective tissue, epithelial tissue, muscle tissue, and nervous tissue. Connective tissue supports other tissues and binds them together (bone, blood, and lymph tissues). Epithelial tissue provides a covering (skin, the linings of the various passages inside the body).
Muscle tissue includes striated (also called voluntary) muscles that move the skeleton, and smooth muscle, such as the muscles that surround the stomach. Nerve tissue is made up of nerve cells (neurons) and is used to carry "messages" to and from various parts of the body.
