Final answer:
Airway resistance is not typically significant in gas flow due to the presence of pulmonary surfactant which reduces alveolar surface tension, and the lungs' ability to stretch, known as lung compliance, facilitating easier airflow and respiration.
Step-by-step explanation:
Airway resistance is considered insignificant in relationship to gas flow in the lungs because of several factors that facilitate breathing despite the natural tendency for resistance to slow down motion. These factors include the production of pulmonary surfactant which reduces the surface tension within the alveoli, preventing them from collapsing during expiration, and the concept of lung compliance, which refers to the ability of the lungs to stretch. The more compliant the lungs are, the higher their potential volume, leading to a decrease in airway resistance and smoother gas flow during respiration.
Changes in resistance can dramatically affect breathing; for instance, if lung compliance decreases due to restrictive diseases, or if resistance increases because of conditions like asthma or emphysema, breathing becomes more difficult. However, adequate lung compliance and the presence of pulmonary surfactant work together to help maintain low airway resistance, thus allowing for efficient gas flow despite possible changes in the size or diameter of the airways due to various health conditions.