AP BIOLOGY

Detailed explanation-1: -A typical heart has two upper and two lower chambers. The upper chambers, the right and left atria, receive incoming blood. The lower chambers, the more muscular right and left ventricles, pump blood out of the heart.

Detailed explanation-2: -A typical heart has two upper and two lower chambers. The upper chambers-the right and left atria-receive incoming blood. The lower chambers-the right and left ventricles-pump blood out of your heart.

Detailed explanation-3: -In humans the atria are the two upper chambers of the heart. Each is roughly cube-shaped except for an ear-shaped projection called an auricle. (The term auricle has also been applied, incorrectly, to the entire atrium.)

Detailed explanation-4: -Structure of the Heart The heart has four chambers: two upper chambers call the right and left atrium and two lower chambers called the right and left ventricle. There is a wall between the two atria called the atrial septum. There is another wall between the two ventricles, and it is called the ventricular septum.

Detailed explanation-5: -The two atria are thin-walled chambers that receive blood from the veins. The two ventricles are thick-walled chambers that forcefully pump blood out of the heart.