Circulatory System Key Concepts What are blood’s components and their functions? What is blood pressure and why is it important? How is heart rate affected by exercise? Key Terms Circulatory system Blood Red blood cell Artery Vein Capillary THE CIRCULATORY SYSTEM WORKS WITH OTHER BODY SYSTEMS The circulatory system transports materials from the digestive system and the respiratory system to cells of the body. It works with the respiratory system to transport oxygen to cells of the body and remove carbon dioxide and other wastes. The circulatory system supplies blood, a fluid that carries materials and wastes, to all parts of the body. STRUCTURES IN THE CIRCULATORY SYSTEM FUNCTION TOGETHER The heart and blood vessels make up the circulatory system. The heart The heart pushes blood throughout the circulatory system and is divided into four chambers. The right atrium receives oxygen-poor blood from the rest of the body. The right ventricle pumps the oxygen-poor blood to the lungs. The left atrium receives oxygen-rich blood from the lungs. The left ventricle pumps oxygen-rich blood to the rest of the body. Blood Blood is a tissue made up of four components. Plasma contains proteins, sugar, hormones and gases and makes up most of the blood. 60% of blood White blood cells help your body fight infection. Red blood cells carry oxygen to other cells of the body. Platelets are large cell fragments that help form blood clots. Wrap your head around this In one cubic millimeter of blood, the size of a grain of rice, you have about 5 million red blood cells (life span about 120 days) In the same amount you have about 5-10 thousand white blood cells (from a few days to many months) In that same amount you have about 400,000 platelets (from five to nine days) Blood Vessels Blood vessels are structures that blood flows through. Arteries are vessels that take blood away from the heart. Veins are blood vessels that carry blood back to the heart. Capillaries connect arteries with veins and are the sites where materials are exchanged between blood and tissues. Try this Hold one hand above your head and the other at your side for one minute The fingertips of the hand held down will be redder, indicating that blood flowed down. Blood Exerts Pressure on Blood Vessels Blood pressure is the force that blood exerts on blood vessels. Low blood pressure can keep oxygen and other materials from other cells. High blood pressure causes strain on arteries and veins and can cause the heart to work harder than it should. There Are Four Different Blood Types Each red blood cell contains proteins that determine blood type. People with type A protein have type A blood. Type B proteins produce type B blood. People without either protein have type O blood. Some people have both A and B proteins, resulting in AB type blood. Blood Type Cardiovascular Problems Atherosclerosis- when cholesterol builds up inside of blood vessels causing narrowing and blockage Hypertension- abnormally high blood pressure which can lead to heart attack, kidney disease, and stroke. Stroke- when a blood vessel in the brain becomes clogged or ruptures. Brain receives no oxygen, brain dies.