bio - circulation

explain what an open and closed circulatory system is:

open system:

• is in insect, arthropods and molluscs

• its passive, not very efficient

• hemolymph is just floating around

• it does have a pumping organ (heart)

closed system:

• in some invertebrates and all vertebrates

• more efficient

• its good for animals having high metabolic demands

• blood is confined to vessels, arteries, veins, capillaries and separate from IF

explain single circulation, double circulation (amphibians) and double circulation (mammals and birds)

single circulation: in here they only have 1 Atrium and 1 Ventricle.

• heart only has deoxygenated blood

• blood passed 2 capillary beds before returning to the heart

• advantage: very simple system

• disadvantage: heart doesnt have oxygenated blood

double circulation (amphibians): 2 Atrium and 1 Ventricle

• 3 chambered heart

• ventricle pumps blood in the arteries
  

double circulation (mammals and birds): 2 Atrium and 2 Ventricles

• 4 chambered heart

• oxygen rich and poor do not mix

• higher capacity for high metabolic need

• the oxygenated blood goes through 2 capillaries: one to the head and one to the limbs

the superior and inferior vena cava bring

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