Model hearts

Sycamore had a great time creating a chamber of the heart! The heart has two features that keep blood flowing in the right direction. These are chambers and valves. Chambers fill with blood, then squeeze to pump the blood out. Each side of the heart has an entry chamber  (atrium) and an exit chamber (ventricle). These pump one after the other to keep the blood flowing around. Valves stop blood flowing backwards. When the ventricle contracts, the atrium’s exit valve closes so blood cannot fall back into it. When the ventricle relaxes its exit valve closes to stop blood flowing backwards. The children managed to replicate this using only a jar, balloons and straws!