EXSS2022 Lecture Notes - Lecture 13: Heme Oxygenase, Endocrine System, Nitric Oxide

• School: University of Sydney
• Department: Exercise and Sport Science
• Course: EXSS2022
• Professor: Chin Moi Chow

Document Summary

Hypoxemia (low o2): the lower the sao2, the more rapid the onset, altitude, rate of ascent, extent of prior acclimatization, fitness, gender, age, general health, obesity. Major cause = brain swelling: hypoxia impairs brain ion pumps. Altitude & pb: moderate altitude: >1000m, high altitude: >3000m, extreme altitude: >4000m. Physiological responses to altitude: acute: seconds several hours, short-term: several hours days/months, long-term: years life-long. Increase o2 unloading at tissue level: ans (epi, ne, endocrine system, cellular & molecular changes, cellular adaptation, increased mb mrna. Increase in ~16% mb production: makes o2 available to muscles. Body weight: weight loss marked decrease in body mass. Ventilatory acclimatisation: ventilation gradually increases for several days then reaches a plateau at a new higher level. Increases pao2 even though original hypoxic stimulus remains unchanged (or even decreased at the chemoreceptors) Increased gain of peripheral chemoreceptors: increased gain = increased output of the chemoreceptors (i. e. increase ve)