Kin 470 1st Edition Lecture 12Outline of Last Lecture I. central command theory II. respirationIII. lung function Outline of Current Lecture II. Conducting and Respiratory zonesIII. Positioning of organsIV. Mechanics of breathingCurrent LectureConducting zoneConducts air to respiratory zoneHumidifies, warms, and filters airExchange of gases between air and bloodPosition of lungs, diaphragm and pleuraLungs are enclosed by membranes called pleura Visceral pleura On outer surface of lung Parietal pleura Lines the thoracic wall Intrapleural space Intrapleural pressure is lower than atmospheric Prevents collapse of alveoli Mechanics of breathing• Movement of air • Due to Dpressure (bulk flow)• InspirationDiaphragm pushes downward, ribs lift outwardVolume of lungs increasesThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.¯Intrapulmonary pressure • ExpirationDiaphragm relaxes, ribs pulled downwardVolume of lungs decreasesIntrapulmonary pressure raisedAirway resistance• Airflow depends on:Pressure difference between two ends of airwayResistance of airways• Airway resistance depends on diameter of airwayChronic obstructive lung diseaseAsthma and exercise-induced asthmaPulmonary ventilation• The amount of air moved in or out of the lungs per minute (V) Tidal volume (VT)Amount of air moved per breathBreathing frequency (f)Number of breaths per minuteAlveolar ventilation (VA)Volume of air that reaches the respiratory zoneDead-space ventilation (VD)Volume of air remaining in conducting