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.
They carry oxygen-rich blood from the aorta to the heart muscle, which must have its own blood supply to function. Veins. The veins also are major blood vessels connected to your heart. The pulmonary veins carry oxygen-rich blood from the lungs to the left side of the heart so it can be pumped to the body. The superior and inferior vena cavae are large veins that carry oxygen-poor blood from the body back to the heart.