BIOM20002 Lecture Notes - Lecture 46: Aorta, External Intercostal Muscles, Brainstem

• School: University of Melbourne
• Department: Biomedicine
• Course: BIOM20002
• Professor: All

Document Summary

To provide oxygen for electrons in the etc. Evolution dictates breathing as a survival necessity. Aids in regulation of blood ph by altering amount of h+-generating co2 inhaled. Provides additional pathway for water loss and heat elimination. Defends against inhaled foreign matter and filtration of matter by cilia and mucus. To enable breathing in, a pressure gradient needs to be established. Intra-alveolar pressure needs to be smaller than atmospheric pressure to suck air in (because air moves following pressure gradient from high to low), which is enabled by increase in lung volume (by diaphragm contraction) Previous exhalation pushes air out and make the lung like a vacuum. To keep the lung inflated, pleural sac/fluid pressure needs to be lower than alveolar pressure, otherwise air will deflate into pleural sac down pressure gradient (from low high) The potential space between parietal and visceral membranes.