Circulatory
system
, Human circulatory system
Circulatory systems in animals
Types of circulatory systems
Ensure body functions correctly & remains healthy, specific substances moved around body
Classify circulatory systems as open or closed
Further describe closed circulatory systems as single or double
Open circulatory system Closed circulatory system
Blood remains enclosed & circulates within blood
Blood pumped at low pressure by heart into 1 large blood vessel.
vessels. Blood no direct contact w/ body tissues.
Releases blood into series of blood spaces make up haemocoel.
Blood pumped rapidly around body under high pressure.
Blood bathes internal organs & moves slowly through tissues. Exact distribution of blood controlled, effective system.
Blood enters open-ended veins & returns to heart. Tissue fluid between blood vessels & cells enables
Distribution of blood to tissues poorly controlled. diffusion of substances between blood by tissue fluid &
body tissues.
Only suitable for small organisms, invertebrates, eg. mollusks &
Suitable for larger, complex organisms, annelids &
arthropods. vertebrates, humans.
Transport systems in humans
Cardiovascular circulatory systems
Single circulation pathways Venous heart
A fish has venous heart, means receives only deoxygenated blood, heart pumps blood to gills to
get oxygen & then blood pumped to body. Blood passes once through heart, single circulation.
Double circulation pathways Arteriovenous heart
Amphibians, some reptiles, birds & mammals have arteriovenous heart, has arteries & veins.
Arteries carry oxygenated blood, veins carry deoxygenated blood, both connected to heart.
Blood goes twice to heart & pumped out twice, double circulation pathway.
First time pumped to lungs (pulmonary circulation), second time to rest of body (systemic
circulation).
Human blood circulatory system
Moves +/- five litres of blood
Heart, lungs, & blood vessels make up circulatory system.
system
, Human circulatory system
Circulatory systems in animals
Types of circulatory systems
Ensure body functions correctly & remains healthy, specific substances moved around body
Classify circulatory systems as open or closed
Further describe closed circulatory systems as single or double
Open circulatory system Closed circulatory system
Blood remains enclosed & circulates within blood
Blood pumped at low pressure by heart into 1 large blood vessel.
vessels. Blood no direct contact w/ body tissues.
Releases blood into series of blood spaces make up haemocoel.
Blood pumped rapidly around body under high pressure.
Blood bathes internal organs & moves slowly through tissues. Exact distribution of blood controlled, effective system.
Blood enters open-ended veins & returns to heart. Tissue fluid between blood vessels & cells enables
Distribution of blood to tissues poorly controlled. diffusion of substances between blood by tissue fluid &
body tissues.
Only suitable for small organisms, invertebrates, eg. mollusks &
Suitable for larger, complex organisms, annelids &
arthropods. vertebrates, humans.
Transport systems in humans
Cardiovascular circulatory systems
Single circulation pathways Venous heart
A fish has venous heart, means receives only deoxygenated blood, heart pumps blood to gills to
get oxygen & then blood pumped to body. Blood passes once through heart, single circulation.
Double circulation pathways Arteriovenous heart
Amphibians, some reptiles, birds & mammals have arteriovenous heart, has arteries & veins.
Arteries carry oxygenated blood, veins carry deoxygenated blood, both connected to heart.
Blood goes twice to heart & pumped out twice, double circulation pathway.
First time pumped to lungs (pulmonary circulation), second time to rest of body (systemic
circulation).
Human blood circulatory system
Moves +/- five litres of blood
Heart, lungs, & blood vessels make up circulatory system.
