Chapter 32 Circulation
CV Comparison Lab
Link for CV Evolution Tutorial:
Circulatory System III: The Heart http://educationportal.com/academy/lesson/circulatory-system-iii-theheart.html#lesson
Mills AP Bio 2013
Describe two
invertebrates and
six vertebrates of
increasing
complexity.
Describe:
How each system works.
What are the advantages of the system to the organism?
Include labeled color pictures for each.
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Video
http://www.youtube.com/watch?v=6TCT5zRX0lU&list=PL89C59A3264EA05E1
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Of Bio
Animals
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2013
Chapter 32 Circulation
Transport in Invertebrates
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Chapter 32 Circulation
Transport in Vertebrates
• Comparison of
Circulatory Pathways
in Vertebrates
– One circuit – single loop
– Two circuit – double loop
• 2 atria, single ventricle
• 2 atria, 2 ventricle (right
and left sides divided)
(See next slide for better picture)
Mills AP Bio 2013
Chapter 32 Circulation
Although onlyin
oneVertebrates
ventricle, there is
Transport
little mixing of blood. Some reptiles
have a partial wall dividing ventricle.
Crocodile has a heart like mammals
and birds.
Mills AP Bio 2013
Chapter 32 Circulation
Transport in Vertebrates
Mills AP Bio 2013
Chapter 32 Circulation
Transport in Vertebrates
Shape of ventricles minimizes mixing of blood:
Oxygenated blood from LA exits to ventricle and enters carotids to go to brain.
Deoxygenated blood from RA exits to ventricle to pulmocutaneous vessels to go to skin
and lungs.
Mixed blood from both artia exits ventricles to aortic arch to go to rest of body.
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Unique Crocodile Heart
• http://www.abc.net.au/science/news/stories/s167223.htm
Special connective tissue valve in right ventricle can
close off blood going to lungs and shunt it to the body.
Crocodile can stay under water for a couple of hours.
(We will come back to this later in PPT)
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Unusual Adaptations
Cog tooth valve is made of connective
tissue knobs and responds to adrenalin.
Normal valves are just passive flaps. When
diving there is more adrenalin and this
causes the cog teeth to close.
When under water, blood is diverted
around the lungs. Blood exits right
ventricle into the “left” (see next slide)
aorta (yellow arrow), which then joins
the “right” aorta. The pulmonary trunk
(white arrow) is closed off by an
evolutionarily unique “cog tooth” valve of
connective tissue.
• Crocodile has unique solution
– How can the air breathing croc stay underwater for
hours at a time?
L Aorta-To posterior body
To lungs
R Aorta-To brain and
small amt to posterior
body
http://www.abc.net.au/science/news/space/SpaceRepublish_167223.htm
See also: www.palaeos.com/.../Units/290Crocs/290.100.html
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When diving, blood
exits ventricle here (left
aorta – named after
bend), and pulmonary
trunk closes.
Valve closed
to left aorta
http://www.auburn.edu/academic/classes/zy/0301/Topic12/Topic12.html
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Valve open to
left aorta.
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