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.
   The right atrium is where the major veins (vena cava)  connect to the upper part of the heart, returning deoxygenated  blood from the body.Blood then flows through the tricuspid  valve from the right atrium into the right ventricle.   The right ventricle is the lower part of the right side.The  right ventricle contracts to push blood through the pulmonary  valve into the pulmonary arteries, which connect to the lungs.    The left atrium receives the blood that returns from the  lungs in the pulmonary veins.lood then flows through the  mitral valve into the left ventricle.   The left ventricle contracts to pump the blood out through  the aortic valve into the aorta (a large expandable  artery), from which blood flows out into the other arteries. . + 180 others found this useful. Lisa Frost.