Year 6- Blood Heart

Year 6 have been completing their Blood Heart Science topic. They looked at pig hearts to identify the major parts of the human circulatory system. They were challenged to identify the external features, including the major blood vessels, such as the aorta and vena cava. They worked out how blood flows through the heart by pouring coloured liquid into the vessels, one at a time, and noting which vessel the liquid appears out of (if the liquid doesn’t flow, then the vessel is an out vessel and has valves preventing the water flowing the wrong way).
How do the blood vessels entering and leaving the heart look and feel? How thick and tough are they?