Heart or heart like organs force blood through
these vessels
Nutrients and oxygen reach body tissue by
diffusing across thin wall capillaries, the smallest
blood vessels
Blood is completely contained within blood
vessels can be pump under higher pressure, more
efficient than open system.
Single and double loop circulation
Two main types of circulatory system of vertebrates
Single loop circulation : animals with gills have a single
loop with single pump that force the blood around the body
in one direction
Double loop circulation: most vertebrates with lungs use
lung for respiration have double loop, two pump
circulatory system
Single loop
Fish with 2 chambered heart
Atrium and ventricles
Atrium : receive blood from
body
Ventricles : pump the blood out
of heart to gill.
Oxygen rich blood travel from
gill to the rest of body and
returns, oxygen poor to atrium
Double loop
Vertebrate with large body, get bigger
capillaries,
Single pump to make blood through
body become difficult.
1st loop : one side of heart, force
oxygen poor blood from heart to
lung.
Blood get oxygen from lung, return to
heart.
2nd loop: another side of heart pump
this blood to the rest of body.
Oxygen poor blood from the body
return to heart