Chapter 34.2, Problem 3MI

Summary Introduction

To define:

The terms breathing, external respiration, internal respiration, trachea, bronchus, lungs, and alveolus.

Explanation of Solution

Breathing: It is the process of movement of air in and out of the lungs. In this process, the carbon dioxide rich air from the lungs are expelled into the external environment and fresh air is inhaled.

External respiration: it is the process of respiration which involves the exchange of gases from the air and blood, that is between alveoli and blood.

Internal respiration: It is the process of gas exchange between the blood and the cells. The gases from the blood are diffused into the interstitial fluid and from there the cells take up the gases and similarly the carbon dioxide is released.

Trachea: The trachea or a wind pipe is tube like structure that connects nostrils and lungs. It is the tube through which the air is passed in out of the lungs to the external environment.

Bronchus: The trachea is bifurcated into two tubes which conduct the air into the lungs and these tubes are called bronchi.

Lungs: Lungs are the balloon like structure present in the thoracic region of the animals. It is involved in breathing and exchange of gases and act as a central organ of the respiratory system.

Alveoli: These are tiny sac like structures at the end of the bronchioles. These are lined by blood vessels and have very thin wall. Inside the lungs, these are the main site of gas exchange.