SA node is located:

Explanation

It is located in the upper lateral wall of right atrium The upper lateral wall of the right atrium primarily contains the openings of the superior vena cava (SVC) and the right pulmonary veins. These structures allow blood to enter the right atrium from the systemic circulation (via the SVC) and from the lungs (via the right pulmonary veins). The superior vena cava is a large vein that carries deoxygenated blood from the upper body, including the head, neck, and upper limbs, back to the heart. It enters the upper lateral wall of the right atrium, near the junction with the right atrial appendage. The right pulmonary veins are responsible for carrying oxygenated blood from the right lung to the heart. The openings of the right pulmonary veins are also located in the upper lateral wall of the right atrium, typically in close proximity to the SVC. Together, these structures play a crucial role in directing blood flow into the right atrium, which is then pumped into the right ventricle for subsequent circulation to the lungs. In the context of the heart, the lower lateral wall refers to a specific region of the left ventricle. This area is supplied by the circumflex artery, one of the main branches of the left coronary artery. The circumflex artery wraps around the left side of the heart and supplies blood to the lower lateral wall as well as other regions of the heart, such as the lateral wall and the posterior wall of the left ventricle.