The Circulatory System

Open circulatory system “Blood” is emptied into the body cavity

Advantage over open CS – Delivers blood to depth of organ more efficiently Disadvantage of 2 chambers – Lack of pressure to transport blood

Evolution of heart Additional atrium Benefit – Increases pressure – But not enough to provide O2 for long distance travel

Inferior Vena cava Superior Vena cava Subclavian Vein Brachiocephalic Vein Renal Vein Pulmonary Artery Pulmonary Vein Left Carotid Artery Brachiocephalic Artery Jugular Vein

Closed Circulatory Systems Two sections for gas exchange – Pulmonary – Systemic One location for pumping blood – Two chambers Receiving : Atrium – Coming in from veins Pumping : Ventricle – Going Away Arteries Problems with this design?

Closed Circulatory Systems 2 sections for gas exchange 1 location for pumping blood – Three chambers Receiving : Atria – Right A. Coming in from body veins – Left A. Coming in from lungs Pumping : Ventricle – Going Away to body – Going Away to lungs Problem with Design? Advantages?

Closed Circulatory Systems Four chambers – Receiving : Atria Right A. Coming in from body veins Left A. Coming in from lungs – Pumping : 2 Ventricles Left V: Going Away to body Right V. Going Away to lungs

Fetal Pig Circulatory System