7.1 Introduction to the Respiratory System
Learning Objectives
After studying this chapter, you will be able to:
- List the structures of the respiratory system
- List the major functions of the respiratory system
- Outline the forces that allow for air movement into and out of the lungs
- Outline the process of gas exchange
- Summarize the process of oxygen and carbon dioxide transport within the respiratory system
- Create a flow chart illustrating how respiration is controlled
- Discuss how the respiratory system responds to exercise
- Describe the development of the respiratory system in the embryo
Introduction
Take a deep breath—and now try holding it. How long can you last? If you’re already feeling the urge to exhale, you’re not alone. Most humans can’t go without breathing for more than a few minutes. Even if you try to resist, your autonomic nervous system will eventually override your willpower, forcing you to breathe. Why? Because every cell in your body depends on a continuous supply of oxygen to perform oxidative cellular respiration—the process by which energy, in the form of adenosine triphosphate (ATP), is produced.
Oxygen is essential for the final stage of cellular respiration, known as oxidative phosphorylation. In this process, oxygen acts as the final electron acceptor, while carbon dioxide is generated as a waste product. Interestingly, it’s not the lack of oxygen but the buildup of carbon dioxide that primarily triggers your drive to breathe.
The respiratory system is responsible for facilitating this critical gas exchange. It includes the muscles that drive ventilation, the airways that carry air to and from the lungs, and the delicate alveolar surfaces where oxygen enters the bloodstream and carbon dioxide exits. Working closely with the circulatory system, the respiratory system ensures that gases are efficiently transported to and from tissues throughout the body.
Disorders such as asthma, emphysema, chronic obstructive pulmonary disease (COPD), and lung cancer can severely impair this system. These conditions disrupt normal airflow and gas exchange, leading to labored breathing and diminished oxygen delivery—reminding us just how vital and vulnerable the respiratory system truly is.
Louisiana Lagniappe
Louisiana, home to one of the highest concentrations of chemical plants in the United States, presents unique public health concerns related to air quality and respiratory health. Prolonged exposure to pollutants such as volatile organic compounds (VOCs), benzene, formaldehyde, sulfur dioxide, and particulate matter can contribute to the development of serious respiratory conditions.
One major disease associated with such exposures is Chronic Obstructive Pulmonary Disease (COPD), which includes chronic bronchitis and emphysema. Inhalation of chemical irritants over time can lead to airway inflammation, mucus overproduction, and progressive narrowing of the bronchi and bronchioles, making breathing increasingly difficult.
Another concern is chemical pneumonitis, a condition caused by the inhalation of toxic chemical fumes. This can lead to inflammation of lung tissue, alveolar damage, and in severe cases, respiratory failure. In communities near industrial sites—such as those along the Mississippi River corridor often referred to as “Cancer Alley”—residents have reported higher incidences of asthma, COPD, and even lung cancer, possibly linked to long-term exposure to industrial emissions.
Public health efforts in Louisiana emphasize the importance of monitoring air quality, limiting exposure, and implementing protective measures for workers in high-risk industries. Continued research and environmental advocacy remain vital for protecting the respiratory health of residents and workers alike.