Lecture 6 - Cardiovascular and Respiratory Systems

Blood brings deoxygenated blood to gills deferent

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Unformatted text preview: a7on and circula7on –  Ven7la7on: movement through respiratory medium •  air or water –  Circula7on: fluid that carries O2 and CO2 •  Hemolymph in invertebrates •  Blood in vertebrates 11 Insects •  Trachea: network of air ­filled tubes that branch through all 7ssues of insects body •  Respiratory gasses diffuse through air •  Spiracles (gates) close to decrease water loss and open to allow for gas exchange 12 Countercurrent flow  ­ Fish •  Water flows unidirec7onally from the mouth, through the gills and out at the operculum •  Thin gill filaments (lamellae) minimize exchange surface •  Lamellae blood flow is unidirec7onal and in opposite direc7on to water flow –  Increased Oxygen par7al pressure to maximize gas exchange –  Afferent: Oxygen ­poor blood – brings deoxygenated blood to gills –  Deferent: Oxygen ­rich blood – take away oxygenated blood from gills 13 Unidirec7onal ven7la7on  ­ birds •  Minimal air lef afer exhala7on –  Humans lungs are never empty afer exhala7on •  Air sacs –  Distributed along the body –  Not a gas exchange surface –  Inhaled oxygenated air comes into posterior sacs. As the bird exhales, air moves into anterior sacs passing unidirec7onally through the lun...
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This document was uploaded on 03/05/2014.

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