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.
The Heart. Structure. The heart is divided into four chambers: the right atrium and right ventricle, and the left atrium and left ventricle. The walls of the chambers are made of a special muscle, the myocardium, which contracts rhythmically under the stimulation of electrical currents.