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.
  Blood vessels which carry blood back to the heart from the rest of the body are called veins.   The main vein is the vena cava, which carries deoxygenated blood to th â¦ e right atrium. The pulmonary vein carries oxygenated blood from the lungs to the left atrium.