Heart although this description is disputed, as the heart is likely to be slightly larger. Well-trained athletes can have much larger hearts due to the effects of exercise on the heart muscle, similar to the response of skeletal muscle. 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. There is an ear-shaped structure in the upper right atrium called the right atrial
Lateral ventricles using linear or planar measurements. The volume of the lateral ventricles are known to increase with age. They are also enlarged in a number of neurological conditions and are on average larger in patients with schizophrenia, bipolar disorder, major depressive disorder and Alzheimer's disease. Asymmetry in the size of the lateral ventricles is found in about 5–12% of the population. It has been associated with handedness, where right-handed people have been found to have a larger right lateral ventricle and a longer left occipital horn, whereas left handed people have been found to have longer right occipital horns. A severe