Chapter 34, Problem 14A

Summary Introduction

To explain:

The structure in which external respiration takes place.

Introduction:

The respiratory system is the connection of organs and tissues that controls our breathing. It consists of our airways, lungs and blood vessels. The muscles that strengthen our lungs are additional components of the respiratory system. These parts function together to support our body and absorb oxygen from the air for efficient functioning of our organs. It additionally cleans waste gases like carbon dioxide from our blood. Common troubles consist of allergies, diseases or infections.

Explanation of Solution

Gas exchange in the lungs is referred to as external respiration as one portion of the respiratory membrane, i.e., the alveolar air, is literally outside of the body. As blood flows through pulmonary capillaries, oxygen diffuses into the blood and carbon dioxide diffuses into the alveolar gas. The partial pressure gradient of every gas equilibrates as blood transfer through the pulmonary capillaries. Therefore, partial pressure of oxygen is 100 mmHg and the partial pressure of carbon dioxide is 40 mmHg inside the blood leaving the lungs. This oxygen-rich blood then transfers to the tissues where oxygen is needed to make ATP as a supply of energy.

Conclusion

External respiration takes place in the lungs wherein oxygen diffuses into the blood and carbon dioxide diffuses into the alveolar air. Internal respiration takes place in the tissues which are involved in metabolism, wherein oxygen diffuses out of the blood and carbon dioxide diffuses out of the cells.