Section LW VENNEATION
7 Section I VENTILATION
Ventilation Occurs because the thoracic cavity changes volume Insipiration uses external intercostals and dlaphragm Expiration is passive at rest, but uses internal intercostals and abdominals during severe respiratory load Breathing rate is 10-20 breaths/minute at rest 40-45 at maximum exercise in adults 8
8 • Occurs because the thoracic cavity changes volume • Insipiration uses external intercostals and diaphragm • Expiration is passive at rest, but uses internal intercostals and abdominals during severe respiratory load • Breathing rate is 10-20 breaths / minute at rest, 40 - 45 at maximum exercise in adults Ventilation
Thoracic Walls and Muscles of respiration Copynight e The McGraw-Hill Companies. inc Permission requred for re End of expiration Sternocleido End of mastoid inspiration Scalene Labored breathing Additional muscles Muscles Pectoralis Clavicle contract, causing of minor additional expansion Inspira- (cut) of the thorax tion External inter. Internal costals inter- costals Muscles Di phragr Ab expiration dominal uscles Diaphrag Quiet breathing: relaxed The external Ab intercostal dominal muscles contract, muscles elevating the relax ribs and moving the sternum The diaphragm contracts, increasing the superior-inferior b dimension of the thoracic cavity
9 Thoracic Walls and Muscles of Respiration
Thoracic Volume eThe MoGraw-Hill Companies, Inc. Pemission required for reproduction or display Vertebra Sternum Lateral Anterior Increase Increase in volume in volume Sternum
10 Thoracic Volume
Copyright e The McGraw-Hill Companies. inc Permission required for reproduction or display Parietal pleura Pleura Pleural cavity Visceral pleura ng Esophagus (in posterior mediastinum) Right Right primary lung Vertebra Root bronchus Left lung of Right pul lung 1 monary artery Parietal pleura at Pleural cavity hilum Right pul monary vein Visceral pleura Pulmonary trunk Fibrous Heart pericardium Visceral pericardium (b) Anterior mediastinum-p Parietal pericardium ernum Pericardial cavity
11 Pleura