Chap 23 Flashcards
Where are the lungs located in relation to the mediastinum?
On either side of the mediastinum within the thoracic cavity.
What is the epiglottis?
A flap of elastic cartilage at the top of the larynx that prevents food and liquid from entering the trachea during swallowing.
What is the purpose of the C-shaped rings of hyaline cartilage in the trachea?
Maintain the trachea’s open shape, allowing airflow; the open part of the ‘C’ faces posteriorly to allow for esophageal expansion during swallowing.
What are the differences between the right and left bronchi?
Right bronchus: Wider, shorter, and more vertical; more likely to have inhaled objects lodge here.
Left bronchus: Narrower, longer, and more horizontal due to the position of the heart.
What happens during sympathetic stimulation of bronchioles?
Relaxes the smooth muscle surrounding bronchioles, leading to bronchodilation and improved airflow.
What are Type 1 alveolar cells responsible for?
Gas exchange.
What do Type 2 alveolar cells secrete?
Surfactant.
What is the function of surfactant?
Reduces surface tension in the alveoli, preventing alveolar collapse during exhalation and ensuring efficient gas exchange.
What is ventilation-perfusion coupling?
The matching of airflow (ventilation) to blood flow (perfusion) in the lungs to optimize gas exchange.
What is residual volume?
Air remaining in the lungs after maximal exhalation; prevents lung collapse.
What is dead air space?
Air in the conducting zones (trachea, bronchi) where gas exchange does not occur.
