BIOD33H3 Lecture Notes - Lecture 1: Atmospheric Pressure, Oxidative Phosphorylation, Tidal Volume
A number of physiological challenges come with high altitudes: little oxygen in the environment. Barometric pressure changes (decreases as altitude increases) There is a smaller volume of air pushing down on us, less pressure, as we go up. % of air made up of oxygen is always the same (does not change) Decline in barometric pressure = decline in the partial pressure of oxygen in the air. Animals need oxygen to generate atp, by oxidative phosphorylation. Cannot make atp at a fast enough rate: temperature also drops as altitude increases, low air density, low humidity, high uv radiation. We need oxygen to synthesize atp (oxidative phosphorylation: 90% of oxygen in tissue is used for this. Taking air from environment and bringing it into a respiratory structure. Total (minute) ventilation = breathing frequency x tidal volume. Animals may modify the way they breathe: pulmonary o2 diffusion. Slows down rate at which diffusion occurs: mostly beyond control of animals.