The Circulatory System The circulatory system is the body’s own transport system that carries substances around the body. It’s most important job is to carry oxygen and nutrients to all the cells in the body, and to remove waste from those cells. heart blood vessels blood

The Circulatory System The circulatory system carries two types of blood: oxygen-rich blood oxygen-poor blood blood travelling to the body cells high oxygen content low carbon dioxide content blood travelling away from the body cells low oxygen content high carbon dioxide content

The Heart The organ at the centre of the circulatory system. It pumps blood around the body.

The Heart right side of the heart oxygen-rich blood left side The inside of the heart is divided into two sections so that the two types of blood (oxygen-rich and oxygen-poor) are kept apart. right side of the heart oxygen-rich blood left side of the heart oxygen-poor blood

The Heart and Lungs lungs lungs body’s cells Blood is pumped around the body by the heart. It takes about 30 seconds for blood to go once around the body. The left side of the heart pumps oxygen-rich blood to the rest of the body. Blood picks up carbon dioxide from the body’s cells. This oxygen-poor blood then travels back to the right side of the heart. Next, the right side of the heart pumps oxygen-poor blood to the lungs. In the lungs the blood gets rid of the waste carbon dioxide and collects more oxygen. The oxygen-rich blood then returns to the left side of the heart. lungs lungs body’s cells

The Chambers of the Heart Each section of the heart is called a chamber. There are 4. An upper chamber is called an atrium (plural atria). A lower chamber is called a ventricle. right atrium left atrium right ventricle left ventricle

The Chambers of the Heart The chambers of the heart have different functions. Pulmonary artery - blood to the lungs Aorta - blood to the body Pulmonary vein - blood from the lungs Superior Vena Cava - blood from the body The atria collect blood that enters the heart. The ventricles pump blood out of the heart.

Heart valves Blood always flows in the same direction as it moves through the heart during each circulation of the body. The chambers of the heart are separated by valves which prevent blood from flowing in the wrong direction. Pulmonary Valve - valve leading out of right ventricle Aortic Valve - valve leading out of left ventricle Tricuspid Valve - valve between right atrium and right ventricle Mitral Valve - valve between left atrium and left ventricle

Heart dissection