Manuscript Explicit Constructivism a missing link in i：手稿的显式建构主义缺少的环节在我.pptVIP

下载本文档

1
0
约1.37万字
约 54页
2018-03-24 发布于重庆
举报
版权申诉

Manuscript Explicit Constructivism a missing link in i：手稿的显式建构主义缺少的环节在我.ppt

1、有哪些信誉好的足球投注网站（book118）网站文档一经付费（服务费），不意味着购买了该文档的版权，仅供个人/单位学习、研究之用，不得用于商业用途，未经授权，严禁复制、发行、汇编、翻译或者网络传播等，侵权必究。。
2、本站所有内容均由合作方或网友上传，本站不对文档的完整性、权威性及其观点立场正确性做任何保证或承诺！文档内容仅供研究参考，付费前请自行鉴别。如您付费，意味着您自己接受本站规则且自行承担风险，本站不退款、不进行额外附加服务；查看《如何避免下载的几个坑》。如果您已付费下载过本站文档，您可以点击这里二次下载。
3、如文档侵犯商业秘密、侵犯著作权、侵犯人身权等，请点击“版权申诉”（推荐），也可以打举报电话：400-050-0827(电话支持时间：9:00-18:30)。
4、该文档为VIP文档，如果想要下载，成为VIP会员后，下载免费。
5、成为VIP后，下载本文档将扣除1次下载权益。下载后，不支持退款、换文档。如有疑问请联系我们。
6、成为VIP后，您将拥有八大权益，权益包括：VIP文档下载权益、阅读免打扰、文档格式转换、高级专利检索、专属身份标志、高级客服、多端互通、版权登记。
7、VIP文档为合作方或网友上传，每下载1次，网站将根据用户上传文档的质量评分、类型等，对文档贡献者给予高额补贴、流量扶持。如果你也想贡献VIP文档。上传文档

Manuscript Explicit Constructivism a missing link in i：手稿的显式建构主义缺少的环节在我

Comments: Normally, minute ventilation is about 5 l/min MVV = 125-175 l/min (higher in males cf. females) Thus, there is a great ventilatory reserve; But MVV can be sustained only for a short time Hypoxia and hypercapnia alone are not as potent as severe exercise in stimulating ventilation So, other factors also drive ventilation during exercise. Interaction of ventilatory responses to CO2 and O2 (all partial pressures in mm Hg) 40 50 PACO2 Ventilation (l/min) PAO2 = 40 PAO2 = 55 PAO2 = 100 0 25 50 75 100 Conclusion: Conclusion: Hypoxia makes an individual more sensitive to CO2 excess Ventilation at high altitudes: Barometric (atmospheric) pressure is lower; When PaO2 is 60 mm Hg, min. ventilation ↑ What happens to PaCO2? It is lowered as a result of hyperventilation What happens to pH of arterial blood? pH increases slightly say from 7.4 to 7.45 Arterial blood gases: Hypoxemia (low PaO2); hypocapnia (PaCO2 35 mm Hg); respiratory alkalosis (pH 7.45 because of hypocapnia) Some working definitions for you: Normocapnia: PaCO2 between 35 and 45 mm Hg Hypocapnia: PaCO2 35 mm Hg Hypercapnia: PaCO2 45 mm Hg Hypoxemia: PaO2 80 mm Hg Note: significant activation of carotid bodies occurs only when PaO2 60 mm Hg Effects of breath holding: Respiration can be voluntarily inhibited for some time Eventually, voluntary control is overridden (breaking point) What is breaking due to? Rise in PaCO2 (acute hypercapnia) Fall in PaO2 Individuals can hold their breath longer after removal of carotid bodies; Psychologic factors also contribute Effects of hyperventilation: Overbreathing to exhaustion; Eventually there is a “breaking point” Note a period of apnea following hyperventilation; What is breaking here due to? CO2 lack Overbreathing apnea Effects of chronic hypercapnia: When does chronic hypercapnia occur? What is the basic cause of chronic hypercapnia? Failure to eliminate CO2; (respiratory failure) Reason: reduction in alveolar ventilation Note: acute hypercapnia