Final answer:
Flow-volume loops with expiratory obstruction demonstrate decreased expiratory flow at lower lung volumes.
Step-by-step explanation:
Flow-volume loops with expiratory obstruction demonstrate decreased expiratory flow at lower lung volumes. A flow-volume loop is a graph that shows how much air a person can breathe in or out over time. In cases of expiratory obstruction, such as in obstructive lung diseases like asthma or chronic obstructive pulmonary disease (COPD), the airflow is decreased during expiration, resulting in a decreased expiratory flow.