(国家精品课程生理学)肺与呼吸.pptVIP

Summarize 1.Conception: The movement of air into and out of the body. 机体和外界环境之间进行气体交换的过程。 2.Significance:To provide oxygen and remove carbon dioxide. 保证机体新陈代谢的正常进行，是维持 生命活动的必需过程 3.Courses of respiration: 3.1.外呼吸: Includes two phases: a.肺通气(ventilation): Air into and out of the lungs b.肺换气:Gases exchange between the air in lungs and the blood 3.2气体运输: Transport of gases in the blood 3.3内呼吸: Gases exchange between the blood and the tissues Section 1 Pulmonary ventilation （肺通气） Air into and out of the lungs 一．The function of airway(呼吸道的作用） 二、 Mechanics of pulmonary ventilation （肺通气原理）（一）The motivity of ventilation（动力） 1. 呼吸运动 呼吸肌收缩、舒张 所造成的胸廓扩大 和缩小。 呼吸肌： 呼吸肌： 吸气肌: 肋间外肌 呼吸肌： 2 呼气肌: 肋间内肌 腹壁肌 呼吸肌： 3 辅助呼吸肌 斜角肌 胸锁乳突肌 胸肌 背肌 2．The changes of intrapulmonary Pressure  （肺内压的变化） 吸气初：肺内压 大气压 吸气开始 吸气末：肺内压 = 大气压 吸气停止 呼气初：肺内压 大气压 呼气开始 呼气末：肺内压 = 大气压 呼气停止 负压人工呼吸 正压人工呼吸 3．The intrapleural pressure（胸膜腔内压） （1）胸内压:  胸膜腔内的压力。平静呼吸时始终低于大气压,称胸膜腔负压. 先决条件:胸膜腔是密闭的.根本因素:肺有弹性回缩力a.胸腔的自然容积大于肺的自然容积，使肺处于扩张状态。b.胸膜的壁层不易受大气压的直接影响 胸膜腔内压=大气压–肺回缩力  =0–肺的回缩力 = —肺回缩力 Review: 1.Respiration is the movement of air into and out of the body for provide oxygen and remove carbon dioxide. 2.The process of respiration includes three phases. 3.Mechanisms of respiration : Inspiration occurs when the diaphram contracts and the external intercostal muscles lift the rib cage,thus increasing the volume of the thoracic cavity. Passive expiration during quiet breathing occurs when the muscles of inspira