Circulatory System PART ONE

Platelet White blood cells Red blood cells

The 4 Components of Blood Red Blood Cells- Cells that carry oxygen molecules - They contain hemoglobin - Does not have a nucleus day lifespan White Blood Cells - Immune cells that attack and engulf pathogens - Uses the circulatory system for transportation to sites of injury Platelets- Cellular elements that initiate the blood clotting process - They clump together to create a “plug” to prevent further blood loss Plasma- A pale-yellow liquid - The majority of the liquid is water, the rest is: proteins, glucose, minerals, CO 2 and hormones #1

Purpose & Function of the Circulatory System 1. To transport oxygen and nutrients to the body’s cells. 2. To transport carbon dioxide and wastes away from the body’s cells. 3. To provide a transportation system for our immune system cells. 4. To distribute heat throughout the body. #2

Blood Vessels #3 Artery VeinCapillary

Blood Vessels ArteryCapillaryVein FunctionCarries blood away from the heart at high pressure Site of gas and nutrient diffusion Returns blood to the heart at low pressure Structure of WallThick, muscular, elastic wall Thinnest walls, one cell thick Thin wall, less muscular Size of OpeningNarrowVery NarrowWide Valve?No Yes How does structure meet it’s function? Strength and elasticity needed to withstand the pulsing of the blood, prevents bursting No need for strong walls, as most of the blood pressure has been lost, thin walls allow for diffusion of materials between the vessel and body cells No need for strong walls, as most of the blood pressure has been lost, valves prevents backflow of blood #3

Valves in Veins Prevents Backflow of Blood

Aorta Superior Vena Cava Right Atrium Inferior Vena Cava Tricuspid Valve Right Ventricle Pulmonary Artery Left Atrium Pulmonary Veins Mitral Valve Left Ventricle Pulmonary Valve Aortic Valve #4

Aorta Superior Vena Cava Right Atrium Inferior Vena Cava Tricuspid Valve Right Ventricle Pulmonary Artery Left Atrium Pulmonary Veins Mitral Valve Left Ventricle Pulmonary Valve Aortic Valve

Veins Arteries #5

Right Lung Left Lung