evolution_of_circulatory systems in animalswindows2007


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Evolution of Animal Circulatory Systems Brie Aliabadi BIOSC 20 Los Medanos College

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Which of the following is the circulatory system of a turtle?? Pre-quiz!!!

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Adaptations for… larger size greater complexity increased mobility/activity life on land Animal evolution thus far….

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Multicellularity Symmetry,Tissues Bilateral Symmetry Coelom Segmentation Notocord Deuterostome,endoskeleton Body Cavity Thanks to the evolution of the circulatory system!!!

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Circulation…. Transport Highway! Respiratory System Endocrine System Digestive System Excretory System Immune System Circulatory System Body fluid/temp. stabilization

co-evolution w/ respiratory system no circulatory system open circulatory system closed circulatory system Increasing complexity in vertebrates Key events in the evolution of the circulatory system…

Transport via diffusion high S-V ratio organisms with few cell layers direct exchange w/ environment In the beginning…. No circulatory system!!

Diffusion inefficient! low S-V ratio…. more nutrients more O2 more waste Require more energy!! But … larger animals need more….

most invertebrates heart + short vessels fluid: hemolymph  pressure = slow animal less O2, nutrients needed bathes cells directly The open circulatory system pump hemocoel Pool of hemolymph surrounding organs

all vertebrates & cephalopod, annelid inverts. blood stays in vessels  pressure = fast blood Trends… 1 circuit  2 separate increasing # chambers 1  2 atria 1  2 ventricles The closed circulatory system

H2O = buoyancy less E, O2 needed 1 atrium, 1 ventricle FISH…. 1 circuit , 2 chambers …and with that 1st breath of air…

2 atria 1 ventricle AMPHIBIANS …. 2 circuits , 3 chambers

2 atria 1 partially divided ventricle helps separate O2’d & de-O2’d blood division more advanced in crocs! REPTILES…. 2 circuits , 3.5 chambers

highest E demand 2 atria 2 ventricles O2’d & de-O2’d blood completely separate Mammals & Birds…. 2 circuits , 4 chambers

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Which of the following is the circulatory system of a turtle?? Pre-quiz!!!

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