Lungs

Definition

The lungs are the primary respiratory organs responsible for gas exchange in the human body. They are located in the thoracic cavity and play a vital role in the respiratory system, facilitating the intake of oxygen and the removal of carbon dioxide from the bloodstream.

5 Must Know Facts For Your Next Test

1. The lungs are divided into five lobes, with the right lung having three lobes and the left lung having two lobes.
2. The trachea, bronchi, and bronchioles are the conducting airways that transport air to and from the alveoli, where gas exchange takes place.
3. The lungs are surrounded by a thin, double-layered membrane called the pleura, which produces a lubricating fluid to reduce friction during breathing.
4. The diaphragm, a dome-shaped muscle located at the base of the lungs, plays a crucial role in the mechanics of breathing by contracting and relaxing to draw air in and push it out.
5. The lungs are highly vascular, with a network of blood vessels that allow for the efficient exchange of oxygen and carbon dioxide between the air and the bloodstream.

Review Questions

• Describe the key structures and functions of the lungs within the respiratory system.
  • The lungs are the primary respiratory organs responsible for gas exchange in the human body. They are divided into lobes and contain a network of airways, including the trachea, bronchi, and bronchioles, that transport air to and from the alveoli. The alveoli are the tiny air sacs where the actual exchange of oxygen and carbon dioxide occurs between the air and the bloodstream. The lungs are surrounded by a thin, double-layered membrane called the pleura, which produces a lubricating fluid to reduce friction during breathing. The diaphragm, a dome-shaped muscle at the base of the lungs, plays a crucial role in the mechanics of breathing by contracting and relaxing to draw air in and push it out.
• Explain the embryonic development of the lungs and how this relates to their structure and function.
  • The lungs develop from the embryonic foregut, with the trachea, bronchi, and alveoli forming from the endodermal lining. During the embryonic and fetal stages, the lungs undergo a series of complex developmental processes, including the formation of the airways, the branching of the bronchi, and the maturation of the alveoli. These developmental stages are crucial for the lungs to acquire their unique structure and function, enabling them to effectively facilitate gas exchange in the respiratory system. Disruptions or abnormalities in the embryonic development of the lungs can lead to various respiratory disorders and congenital abnormalities.
• Discuss how the structure and function of the lungs can impact acid-base balance in the body.
  • The lungs play a critical role in maintaining the body's acid-base balance through the regulation of carbon dioxide (CO2) levels. The alveoli in the lungs facilitate the exchange of oxygen and CO2 between the air and the bloodstream. When CO2 levels in the blood increase, the lungs respond by increasing the rate and depth of breathing, known as hyperventilation, to exhale more CO2 and restore the appropriate pH balance. Conversely, if CO2 levels decrease, the lungs will reduce the rate and depth of breathing, known as hypoventilation, to conserve CO2 and maintain the necessary acid-base equilibrium. Disruptions in the structure or function of the lungs, such as lung diseases or respiratory disorders, can lead to imbalances in CO2 levels and subsequent acid-base disturbances, which can have significant physiological consequences.

Related terms

Alveoli: Tiny air sacs within the lungs where gas exchange occurs between the air and the bloodstream.

Bronchi: The large airways that branch off from the trachea and carry air into and out of the lungs.

Pleural Cavity: The space between the lungs and the chest wall, filled with a thin layer of fluid that allows the lungs to slide smoothly during breathing.