Lungs

Definition

The lungs are vital respiratory organs responsible for the exchange of oxygen and carbon dioxide in the body. They play a crucial role in excretion by removing carbon dioxide, a waste product of cellular metabolism, and maintaining acid-base balance in the bloodstream. Proper lung function is essential for overall health, as they not only facilitate breathing but also contribute to other physiological processes.

5 Must Know Facts For Your Next Test

1. The lungs are composed of spongy tissue that allows for flexibility and expansion during inhalation.
2. Each lung is divided into lobes; the right lung has three lobes while the left lung has two lobes to accommodate the heart.
3. The surface area of the alveoli in the lungs is estimated to be about the size of a tennis court, maximizing gas exchange efficiency.
4. The respiratory system also plays a role in regulating blood pH by controlling the levels of carbon dioxide through exhalation.
5. Diseases such as chronic obstructive pulmonary disease (COPD) or asthma can significantly impair lung function and impact the body's ability to excrete carbon dioxide.

Review Questions

• How do the structural features of the lungs facilitate their role in excretion?
  • The lungs' structure, including their spongy tissue and extensive alveolar surface area, is specifically designed for efficient gas exchange. Alveoli allow oxygen to diffuse into the blood while facilitating the expulsion of carbon dioxide, a waste product from cellular metabolism. This structural adaptation enhances the lungs' ability to perform their excretory function effectively, ensuring that harmful gases are quickly removed from the bloodstream.
• Discuss the relationship between lung function and acid-base balance in the body.
  • Lung function is closely linked to maintaining acid-base balance through the regulation of carbon dioxide levels in the blood. When carbon dioxide accumulates due to insufficient exhalation, it can lead to respiratory acidosis, lowering blood pH. Conversely, hyperventilation can cause excessive loss of carbon dioxide, leading to respiratory alkalosis. Thus, effective lung function is essential for stabilizing blood pH and preventing metabolic disturbances.
• Evaluate how diseases affecting lung function can impact overall homeostasis in the body.
  • Diseases like COPD or asthma disrupt normal lung function, which significantly affects homeostasis by impairing gas exchange. Reduced oxygen intake can lead to hypoxia, affecting cellular metabolism and energy production throughout the body. Additionally, inadequate removal of carbon dioxide can cause respiratory acidosis or alkalosis, disturbing acid-base balance and triggering compensatory mechanisms in other organ systems. The interconnectedness of lung health with overall bodily functions highlights its critical role in maintaining homeostasis.

Related terms

Alveoli: Tiny air sacs in the lungs where gas exchange occurs, allowing oxygen to enter the bloodstream and carbon dioxide to be expelled.

Respiration: The process of inhaling oxygen and exhaling carbon dioxide, which involves both external respiration (gas exchange in the lungs) and internal respiration (gas exchange at the cellular level).

Ventilation: The mechanical process of moving air in and out of the lungs, driven by the diaphragm and intercostal muscles, essential for maintaining proper lung function.