BIO202H5 Lecture Notes - Lecture 4: Perfusion, Partial Pressure, Bronchiole
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Fi(cid:272)k"s la(cid:449): used to des(cid:272)ri(cid:271)e diffusio(cid:374) rate, deri(cid:448)ed fro(cid:373) he(cid:374)r(cid:455)"s a(cid:374)d graha(cid:373)"s laws. The amount of oxygen dissolved in a substance is determined by its solubility and by its molecular weight. The shorter the diffusion distance, the higher the diffusion rate; the longer the diffusion distance, the lower the diffusion rate. What can biological creatures alter in this equation: cross-sectional area (a, diffusion distance (x, partial pressure ( p) gradient. External respiration: ventilation: active movement of respiratory medium (bulk flow, perfusion: gas delivery from within the body. The higher the pressure gradient between the internal and external environment, the more oxygen you can extract in the diffusion ratio. Whe(cid:374) (cid:455)ou"re large, to get e(cid:374)ough o(cid:454)(cid:455)ge(cid:374) to sustai(cid:374) the large (cid:448)olu(cid:373)e, it"s a pro(cid:271)le(cid:373) to o(cid:374)l(cid:455) rel(cid:455) on surface area of skin to get oxygen (due to low. Larger animals need a different way of increasing the surface for oxygen exchange (increasing a)
