Circulatory System

Heart Terms Myocardium – The muscle that forms the heart wall. Creates the “beat” of the heart. Endocardium – A tough membrane that lines the four chambers of the heart. Pericardium – The sac or chamber that encloses the heart.

Pericardium Myocardium Endocardium

More Heart Terms Septum – The inner wall that separates the two halves of the heart. Atrium – The upper chamber of the heart (thin wall). Ventricle – The lower chamber of the heart (thick wall).

Pericardium Myocardium Endocardium Septum Left Ventricle Right Ventricle Right Atrium Left Atrium Why are the walls of the ventricles thicker than the walls of the atriums?

Blood Vessels Arteries – blood vessels that carry blood away from the heart. Veins – blood vessels that carry blood back to the heart. Capillaries – blood vessels that connect arteries to veins. Gas exchange occurs in the capillaries.

Blood Vessels of the Heart Aorta – The largest artery, carries blood from the left ventricle to the body. Vena Cava – Blood from the body enters the heart through this vein. Pulmonary Artery – Carries blood from the heart to the lungs (CO2 in blood). Pulmonary Vein – Carries blood from the lungs to the heart.

Pericardium Myocardium Endocardium Septum Left Ventricle Right Ventricle Right Atrium Left Atrium Pulmonary Vein Pulmonary Artery Aorta Superior Vena Cava

Valves  Flaps in the heart that do not allow blood to flow backwards

Heart Valves  Tricuspid – Between right ventricle and right atrium  Mitral – Between left ventricle and left atrium  Pulmonary – Between right ventricle and pulmonary artery  Aortic – Between the left ventricle and the aorta

Aortic Tricuspid Pulmonary Mitral

The Right side of the heart carries deoxygenated blood The left side of the heart carries oxygenated blood.

Let’s see the circulatory system in action!!! Blood Flow Video Basic Blood Flow Through the Heart Complex Blood Flow Through the Heart

7 th Grade - Heart