Final answer:
Forced expiratory volume (FEV) measures the amount of air expelled from the lungs in a specific time frame, while maximum voluntary ventilation (MVV) assesses the total air exchanged in one minute and reveals the respiratory system's endurance and efficiency.
Step-by-step explanation:
The forced expiratory volume (FEV) is a measure of how much air a person can forcefully exhale from their lungs over a specified period, typically one second (FEV1). The maximum voluntary ventilation (MVV) refers to the greatest amount of air that can be inhaled and exhaled within one minute.
FEV is important in the assessment of respiratory function and is commonly used alongside forced vital capacity (FVC) to determine the FEV1/FVC ratio, which helps diagnose and differentiate between restrictive and obstructive pulmonary diseases. A low FEV1/FVC ratio suggests obstructive lung disease such as asthma, where there is airway resistance, whereas a high ratio may indicate restrictive diseases like fibrosis, where the lung is stiff.
MVV involves a more prolonged effort compared to FEV, testing the overall capacity of the respiratory system including muscle strength, compliance of the lung and chest wall, and airway resistance. This test is often utilized to evaluate the endurance of the respiratory muscles and the efficiency of the respiratory system.