sentence: Blood is carried in blood vessels.
sentences_after: These are arteries and veins. Blood going to the heart is carried in veins. Blood going away from the heart is carried in arteries. The main artery going out of the right ventricle is the 'pulmonary artery'. The main artery going out of the left ventricle is the 'aorta'.
concept_name: blood
headings: Heart Structure
categories: Basic English 850 words Anatomy of the cardiovascular system