22. One milliliter ( 1 ml ) of blood could flow through a single capillary in less than 1 hour.
23. Blood flow velocity does not change as the arteries divide and divide again into smaller and smaller vessels.
24. Blood oxygen concentration (ie. content) and PO2 (partial pressure of oxygen are the same, or, are at least linearly related.
25. In the normal systemic circulation, all blood that is ejected from the left ventricle is returned to the right heart by venous flow (consider the pulmonic and Thebesian circulations).