Final answer:
Panacinar emphysema is seen in the entire acinus, including the respiratory bronchioles, alveolar ducts, and alveoli. It more commonly affects the lower lobes and leads to reduced surface area for gas exchange, causing respiratory issues.
Step-by-step explanation:
Panacinar emphysema is typically seen in the entire acinus, which includes the alveoli and all the small airways within the acinus. This type of emphysema affects both the upper and lower lobes but is more commonly associated with the lower lobes. The acinus is the terminal part of the lung's airway and is where gas exchange takes place, composed of the respiratory bronchioles, alveolar ducts, and alveoli.
The main bronchus is a large airway that conducts air to the lungs from the trachea, which itself is a cartilaginous tube that connects the larynx to the bronchi. The alveoli are the tiny air sacs within the lungs where gas exchange occurs, as they have very thin walls that allow oxygen and carbon dioxide to move between the lungs and the bloodstream.
Panacinar emphysema is characterized by the destruction of the entire acinus, leading to reduced surface area for gas exchange and subsequent breathing difficulties. It differs from centriacinar emphysema, which primarily affects the upper lobes and is often associated with smoking.