The Rise of Kâ12 Blended Learning | 133 NSTITUTE NNOSIGHT represents a ranking of 1 st in Santa Clara County and 5 th in California when compared to similar schools with at least 70 percent low-income students.
The heart has four chambers, two upper atria, the receiving chambers, and two lower ventricles, the discharging chambers. The atria open into the ventricles via the atrioventricular valves, present in the atrioventricular septum. This distinction is visible also on the surface of the heart as the coronary sulcus.
One school of thought says that reptile hearts have two atria and one partially divided ventricle, while another says the reptile heart has two atria and two ventricles with an incomplete wall between the ventricles.   For the most part, they all have 3 chambers: 2 atria and one ventrical.