Chapter 22, Problem 8WWTS

Summary Introduction

Introduction:

The alveolus forms the respiratory zone that is predominantly involved in the exchange of gases such as oxygen and carbon dioxide by the process of diffusion to and from the blood. Each respiratory bronchiole extends to forms small, thin walled passages known as alveolar ducts. An alveolus is a small sac that extends from the alveolar duct. The alveolar ducts and the alveoli are lined by simple squamous epithelium without cilia. The human lung has about 150 million alveolar sacs.