Inductive definition of CW complexes. If the largest dimension of any of the cells is n, then the CW complex is said to have dimension n. If there is no bound to the cell dimensions then it is said to be infinite-dimensional. The n-skeleton of a CW complex is the union of the cells whose dimension is at most n.
Deoxygenated blood enters the right atrium through three major veins: the superior and inferior vena cava and the coronary sinus. The superior vena cava returns all of the blood to the heart from tissues superior to the heart in the head, neck, arms and upper thorax.
Overview of the main coronary arteries and cardiac veins. The first branches that radiate from the ascending aorta, as it emerges from the left ventricle, are the left and right coronary arteries, which directly provide an arterial blood supply to the cardiac muscle. They arise from the bilateral aortic sinuses which are situated just distal to the aortic valve.