生理学双语ppt课件 第五章 呼吸.ppt

Chapter 5;Respiratory processes;§ 1. Pulmonary ventilation ? Definition ? Principles of pulmonary ventilation * Driving force Direct ~: pressure changes in alveoli Source ~: contraction of respiratory muscles Inspiratory muscles: Diaphragm, External intercostal muscle Expiratory muscles: Diaphragm, Ext- Internal intercostals Accessory respiratory muscles;Respiratory movement; Types of respiration ?Eupnea Forced breathing (Deep breathing) ?Abdominal Thoracic breathing Principles of pulmonary ventilation ?Contraction (Relaxation) of inspiratory muscles?Expansion (Reduction) of thoracic cavity?(?)Distension (Recoil) of alveoli? Intrapulmonary pressure?(?)() atmo- spheric pressure?Air flows into (out of) the alveoli;Intrapulmonary pressure ?Inspiratory phase: 1 atm ?Expiratory phase: 1 atm ?At the end of inspiration or expiration: =1 atm Intrapleural pressure ?Concept Changes during respiratory cycle More negative as inspiratory processing Less negative as expiratory processing ?Measurement Expression Direct Indirect measurement 775 mmHg or ?5 mmHg Always 1 atm under static condition;Changes of intrapulmonary intrapleural pressure during respiratory cycle;?Formation IAP PRF has opposite directions, so IPP=IAP?PRF At the end of insp- expiration, so IPP=ASP?PRF If ASP=0, IPP=0?PRF= ?PRF IPP: intrapleural pressure IAP: intra alveolar pressure PRF: pulmonary recoil force ASP: atmospheric pressure;Formation of intrapleural negative pressure;?Significance Physiological ~ Distend the lung Make inspiration easier Promote venous lymph return in the chest Pathological ~ (Pneumothorax) Collapse the lung Make inspiration difficult Affect venous lymph return F