BIOL 1107 Lecture Notes - Lecture 28: Fetal Hemoglobin, Thermoregulation, Thoracic Cavity
Document Summary
Highly folded delicate structures that facilitate gas exchange w/ the surrounding water. Need to exchange two gasses: o2 and co2. Doesn"t happen over large surfaces and is relatively slow. Bulk flow: the physical mvt of fluid over a given distance, in addition to diffusion. The mvt of animals respiratory medium (water/air) past a specialized respiratory system. The mvt of a specialized body fluid that carries o2 and. Might see in single cell organisms or aquatic organisms that haven"t developed a very sophisticated. With a large enough surface, diffusion is an extremely effective way to exchange gases and other substances over short distances b/w two compartments. Don"t want the membranes to dry out. Inverts w/ one or a few cells layers use diffusion. Some do not need specialized transport mechs. Some large, complex animal body surfaces may be permeable to gases. Amphibians are the only vertebrates to rely on skin for gas exchange. All air breathing terrestrial vertebrates use lungs.