The Body’s Transport System

1. The Body’s Transport System The Circulatory System

2. The Circulatory System • The Cardiovascular System carries needed substances to cells and carries waste products away from cells. • Consists of the heart, blood vessels, and blood. • Blood contains cells that fight disease (white blood cells). • Blood vessels carry blood to every part of your body. • Blood moves oxygen and nutrients to cells and carries carbon dioxide and other wastes away from the cells. • Blood carries carbon dioxide to the lungs, and we lose it when we exhale.

3. The Heart • The heart is a hollow, muscular organ that pumps blood throughout the body. • It pushes blood through the blood vessels every time it beats. • The heart has four chambers with two on the right and two on the left. • The two sides are separated by a wall called the septum.

4. The Heart • The four chambers are divided between two atria on the top and two ventricles on the bottom. • The atria receive blood coming into the heart, and the ventricles pump blood out of the heart.

5. The Heart • In the right atrium, there are a group of cells that send signals to make the heart contract called the pacemaker. • The atria are separated from the ventricles by valves (flaps of tissue that prevent blood from flowing backward).

6. The Heart • The heartbeat makes a lub-dub sound, which is caused by the opening and closing of the heart valves. • When the valves between the atria and the ventricles close, the lub sound is made. • When the valves between the ventricles and the blood vessels close, it makes the dub sound.

7. KWL: Circulation

8. Pathway of Blood

9. Coronary Circulation • Coronary Circulation is the flow of blood to and from the tissue of the heart. • When the coronary circulation is blocked, oxygen and nutrients cannot reach all the cells of the heart and can result in a heart attack.

10. Pulmonary Circulation • Pulmonary Circulationis the flow of blood through the heart to lungs and back to the heart.

11. Systemic Circulation • Systemic Circulation is the flow of blood to all of your organs and body tissues, except the heart and lungs.

12. Blood Flows Through Two Loops • Loop One: To the Lungs and back to the Heart • Blood from the body goes into the right atrium then to the right ventricle and to the lungs to receive oxygen. • Loop Two: To the Body and back to the Heart • Blood from the lungs goes into the left atrium to the left ventricle to the aorta (largest artery in the body), and it circulates throughout the arteries and capillaries in various organs.

13. Blood Vessels - Arteries • Arteriesare blood vessels that carry blood away from the heart. • Arteries have thick, elastic walls made of connective tissue and smooth muscle tissue. • The pulse is caused by alternating expansion and relaxation of the artery wall.

14. Blood Vessels - Veins • Veins are blood vessels that carry blood back to the heart. • Veins have one-way valves that keep blood moving toward the heart. • The two major veins return blood from your body to your heart are the superior vena cava and the inferior vena cava. • The superior vena cavareturns blood from your head and neck. • The inferior vena cava returns blood from your abdomen and lower body.

15. Blood Vessels - Capillaries • Capillaries are microscopic blood vessels that connect arteries and veins. • The walls of capillaries are only one cell thick and is where oxygen is dropped off and carbon dioxide is picked up.

16. Blood Vessels

17. Blood Pressure • What causes blood pressure? • Blood exerts a force against the walls of the blood vessels. • The force is caused by contraction of the ventricles in the heart. • Measuring Blood Pressure • Measured with a shygmomanometer. • The first number represents the contraction of ventricles. • The second number represents the relaxation of ventricles.