The Circulatory System

Function  Consists of the heart and blood vessels  Carries oxygen and nutrients to the body’s cells and remove carbon dioxide and other wastes  Protects us from disease

Blood  Plasma – the liquid part  Red blood cells – contain hemoglobin, carry oxygen  White blood cells – fight invaders  Platelets – clot blood to stop bleeding

From Blood to Tissues  Substances move in and out of the capillaries by diffusion  Food & oxygen passes into cells from blood  Carbon dioxide & wastes pass out of cells into blood

The Heart  Keeps blood moving through the circulatory system  Constantly beats by first squeezing & then relaxing  Heart beat: normally beats beats per minute  Made of cardiac muscle

Structure of Your Heart  The human heart has 4 chambers with muscular walls  Atria – upper chambers – receive blood into the heart  Ventricles – larger lower chambers – pump blood out of the heart

1. Vein from upper body 1. Vein from lower body 2. Right atrium 3. Tricuspid valve 4. Right ventricle 5. Pulmonary valve 6. Pulmonary arteries 7. Pulmonary veins 8. Left atrium 9. Bicuspid valve 11. Aortic valve 10. Left ventricle 12. Aorta

The Movement of Blood 1.Veins from upper & lower body bring blood that is low in oxygen and high in carbon dioxide into the right atrium. 2.Right atrium pumps blood into the left atrium. 3.Right ventricle pushes the blood to lungs

4.In the lungs, blood picks up oxygen & releases carbon dioxide. 5.Oxygenated blood from lungs is carried to the left atrium. 6.the left atrium sends oxygenated blood into the left ventricle. 7.the left ventricle sends oxygenated blood into the aorta, the main artery leading to the body 8.Arteries carry oxygenated blood all over the body