CIRCULATION Chap The Body’s Transport System

Cardio-Vascular System Also called the circulatory system. Consist of the heart, blood vessels, and blood. The cardiovascular system carries…….. Needed substances to all cells Waste products away from cells Cells that fight disease. White blood cells

Movement of Materials Needed materials: Blood carries oxygen from lungs to the cells Blood carries glucose to cells for energy Waste products: Blood carries carbon dioxide from cells to lungs. Disease fighters White blood cells attack disease causing microorganisms.

Structure and Function The heart is a hollow, muscular organ, about the size of your fist. It is located behind the sternum and inside the ribs. Average heart beats per minute rate is B.P.M. Each heart beat pumps approximately 60 ml. (1/4 of a cup) of blood thru the vessels of your body. DEMO: Can your hands work as fast as your heart? Try this at home. You need two containers. Fill one with water. Find a very small bowl that holds about ¼ of a cup. Every second use the small bowl to transfer water from one container to the other. How long can you las last?

Structure and Function The heart has 2 sides (right and left) Separated by wall of muscle called the septum. Each side has 2 chambers. The upper chambers (called atria) receive blood coming into the heart. The lower chambers (called ventricles) pump blood out of the heart. Each atrium is separated from its ventricle by a one way valve that keeps blood from flowing backwards. One way valves also separate the ventricles from the two major arteries where blood Is pumped out of the heart. Demo: View arm one way valve

Heart Works in 2 Phases In phase 1, the heart atria relax and the atria are filled with blood. In phase 2, the atria contract and fill the ventricles with blood, and the ventricles contract to pump the blood forward. The “lubb-dubb” sound of the heartbeat is made as the valves slam shut.

The Pacemaker The pacemaker is a group of nerve cells located in the right atrium. The pacemaker sends out electrical signals that makes the heart beat. The pacemaker constantly receives stimuli from the brain about the body’s oxygen needs, and responds by adjusting the heartbeat to match the need.

Two Loops After leaving the heart, the blood travels three types of vessels thru-out the body Arteries take blood away from the heart Capillaries connect arteries to veins Veins bring blood back to heart The pattern of the flow is like a figure 8. Heart to lungs and back to heart Blood thru aorta to cells of the body and back to heart

Blood Vessels & Blood