Chapter 21, Problem 7CYR

Summary Introduction

To review:

The statements given below are to be reviewed and corrected accordingly.

a. Type I alveolar cells secrete a chemical called surfactant.

b. Alveolar macrophages are squamous epithelial cells which constitute 90% of the total cells in the alveoli.

c. The respiratory membrane consists of the type II alveolar cells, the pulmonary capillaries’ endothelial cells, and their shared basal lamina.

d. The respiratory membrane must be thick to function effectively in gas exchange.

Introduction:

The respiratory system of the human beings contains nose, pharynx, larynx, trachea, bronchial tree and lungs. The alveoli are that part of the respiratory system which helps in the exchange of the gases needed by our body. The alveoli are always present in a group called alveolar sac.