1.Since fluid dumps into body cavities and sinuses, it mixes with interstitial fluid (fluid that bathes the cells)
a.And so, it is indistinct from interstitial fluid cause it mixes with it
2.Function: transport of materials
1.Arteries and veins
i.Arteries open at end
ii.Veins open at beginning
3.Exchange occurs at hemocoels, which are large cavities/ sinuses found throughout the body
What are hemocoels?
1.Large cavities/ sinses found throughout the body
Explain the pumping organ.
1.Heart; generates force to move hemolymph through the system
Difference between open and closed in terms of heart?
1.One of the other major differences between open and closed is that the heart in an open system has holes called Ostia in it
a.In addition to hemolymph entering heart through veins, it can also enter through ostia
1.Usually a sac around the heart, called pericardium (not same as vertebrates)
a.You will see holes in the heart (the ostia)
i.Only in open circulatory system
ii.Strategically placed all throughout body so there is access to them
Issues of this type:destination of material?
i.issue is that it gets its push from the pumping organ, but the system is open-ended and dumps its material
1.Causes loss of pressure generated by pumping organ
a.Very low pressure because you have open-ended vessels and lose the pressure when the arteries dump out into hemocoel
Issues of this system: efficiency?
i.Very inefficient because the pressures are very low, particularly after they are dumped out in hemocoels
Issues of this system: exchange?
i.EXCHANGE TAKES PLACE IN THE HEMOCOEL
Issues of this type: rate
1.That’s why it’s found in very metabolically slow organisms
Heart--> arteries (High Oxygen)-->hemocoels:
O2 and CO2; nutrients given off to tissues and oxygen and anything else needed; dump in waste; exchange between tissues and circulatory system--> Veins (high CO2)--> respiratory hemocoels (CO2 dumped off and oxygen picked up) --> (2 destinations from here: either heart or more veins)--> heart where it dumps out