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 veins responsible for returning blood to the heart are the Superior and Inferior Vena Cava. Arteries send blood away from the heart, going from Arteries to Arterioles to Câ¦apillaries, then the return is from Capillaries to Venules to Veins. The Superior and Inferior Vena Cava are the veins that send blood to the right atrium after an entire blood circulation cycle.