drydecay-
Open circulatory system
Haemocoel = cavity where blood is held (not in vessels), tube shaped heart which pumps blood along dorsal vessel towards head. Ostia are pores allowing blood back to heart. No respitory gasses carried in blood, oxygen diffuses directly from tracheae.
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Advantages of open circulatory system
Low blood pressure so organisms can live at greater depths in the ocean, less energy demanding and blood bathes tissues directly where exchange of materials take place
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Disadvantages of open circulatory system
Low pressure, slow flow and little control over direction
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Closed circulatory system
Has blood vessels, earthworms have five pairs of 'psuedohearts'. Earthworms - blood pumped from dorsal to ventral vessel. Respiratory gases carried in blood.
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Advantages of closed circulatory system
Larger animals often have closed system as it allows them to control the flow of blood to certain parts of the body. Greater blood pressure generated so blood can flow faster.
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Disadvantages of closed circulatory system
More energy is required, more complex as contains a network of vessels
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Single, closed circulation
Heart ventricle pumps blood to gills, has one atrium and one ventricle, oxygenated blood goes to tissue and deoxygenated blood returns to atrium
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Pulmonary circulation
Consists of all the vessels involved in transporting blood between the heart and lungs
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Systemic circulation
Consists of all the vessels involved in transporting blood between the heart and the body, excluding the lungs
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Advantages of systemic circulation
In systemic circulation when the blood passes through the heart it is given a boost, increasing its rate of flow and enabling oxygen and nutrients to be delivered more quickly to cells. Enables birds/mammals to have a higher metabolic rate than fish and allows blood to be pumped at a higher pressure
