Answer:
They don't have hearts or even an arterial system (veins, arteries). They have an "air system" which is a set of open tubes running through the body from openings on the body called spiracles. It's highly efficient for very small living creatures; it is used by a lot of insects. The problem with it for larger animals is that there is nothing to force higher rates of oxygen when necessary to parts of the body so the system is limited by movement (think of sharks who cannot stop and just float - they don't force water past the gills, their movement forces water through the gills. If the shark stops, he stops breathing -- BAD!) Faster movement can cause faster oxygen flow, to a limit, then the air ceases to flow (turbulence has set in) and oxygen deprivation sets in. {Yay us, boo mosquito.}
Yes- the mammalian heart is a big muscle that has a right and a left side, each with two small chambers: the ventricle and the atrium. Each chamber of the heart pumps at a slightly different time, but each atrioventricular pair pumps closer together than to the other two, leading to to the rhythmic two-pump sound you can hear through your chest.
Your Heart is an organ that pumps blood through your body.
pumps
The heart is a muscle, but it is NOT in the muscular system, and pumps blood to all parts of the body :)
The pumps inside the heart are four chambers that work together to pump blood to your lungs and your body. There are two upper chambers called atria and two lower larger chambers called ventricles.
Ventricles
Ventricles
The heart has 4 chambers. The "collecting chamber of the heart", or the atria , is the two chambers that are located above the other two chambers. It carries the responsibility in helping to pump the blood out of the chambers and making sure no blood pumps back in.
The heart pumps blood through the rest of the body.
Right ventricle
The heart is a muscle, but it is NOT in the muscular system, and pumps blood to all parts of the body :)
The heart is a muscle that pumps blood around the body.