北京大学医学部病理生理学教研室赵亚莉.docx

Clinical Example ? In 1875 three French scientists ascended in a balloon. A height of over 26,000 feet (Bar. 280 mmHg) was reached. They lost consciousness at about 25,000 feet. When Tissandier regained consciousness the balloon was falling rapidly, but his two companions were dead. Oxygen containers were carried in this ascent but Tissandier records that his arms became powerless and so he was unable to raise the mouthpiece to his lips. Why? 氧冬的获得和利用: air alveoli Alveolar capillary Gas transport Tissue cells ventilation gas exchange external respiration I internal respiration U卄 respiraicry— tract .No ml coviV H Pharynx: Laryngopharyru “Larynx n f I / respiratory— trad , JL. XI ?人—J BrQnckicl?s hypoxia的概念 运送■氣茹利用氣发生障碍财,机 体发生功能、代谢、形态生枸欧 支的病理过程. 一、血氧分压 (Partial Pressure of Oxygen, P02) 定义：渣解于血液中的氧所产生的张力。 PaO2 lOOmmHg 影响因素：。吸入毛体氣分压 。外呼吸的功能 三，血氧求量 (Oxygen Capacity) 定义：100 ml血液中Hb彼氧克分砲和 附的景火带氧量。 1.34ml/gx15g/dl = 20ml/dl 体外标准条件(PO2^150 mmHg.二氧化碳 分压为40mmHg,温度为38忙丿下测定 影响因素：Hb的质和量 二，血氣含量(Oxygen Content) 定义：体为100ml治液的卖际帯氧量。 療解氣(0?3nil/dl) +结合氧 A: 19ml/dl V:14ml/dl 影响因素：Hb的质和量；PaO2 动静脉血策爰 定义：动脉血氧令量-眷脉厶氧令量， 反映組狼对氣的摄取和利用能力. 19mVdl 14mVdl A o2o2 °2 °2 O2 V ll 11 5ml/dl 西.血氧饱和度(Oxygen Saturation, S02) 定义：指Hb结合氧的百分教 血氧含量?療解的氣量 x100% 影响因素：PaO2 P?cnf wfuroiion hemoglobin (SOJ ioo 90 80 70 60 50 40 30 K INCREASED AFFINITY Acvfe alkolosii (+ pH)Decreet?d temperaivrB low levels of 2,3 DPG C arbox ybemoghbi ni Methe mogksbin Abnorma! hemoglobin/3 OmalDECREASED AFFINITY Acute ackkxE INCREASED AFFINITY Acvfe alkolosii (+ pH) Decreet?d temperaivrB low levels of 2,3 DPG C arbox ybemoghbi ni Methe mogksbin Abnorma! hemoglobin/ 3 Omal DECREASED AFFINITY Acute ackkxE ■ pH j High Pcq Increased lemperalure Hngh kvek of 23 匚， Abnormol hemogkb?n POj (mm Hg| 第二节 缺氧的原因和发生机制 Causes and Mechanisms of Hypoxia °2不足 r二丿 Causes: 吸入条中PO2过低回 (atmospheric hypoxia) 外呼吸功能障碍 (respiratory hypoxia) 静脉血分流入动脉 海拔高度 (m) 大气压 (mmHg) 大气PO2 (mmHg) 肺泡内PO2 (mmHg) 海平面 760 159 105 1000 680 140 90 2000 600 125 70 3000 5