Why is the part labelled 5 thicker than 6?

Question 1 Report

5 is the left ventricle and 6 the right ventricle

6 is the left ventricle and 5 the right ventricle

5 receives blood from the left auricle and 6 from the right

5 pumps blood round the body and 6 pumps blood into the lungs

5 deals with oxygenated blood and 6 deals with deoxygenated blood