The Circulatory System 1. Using your first two fingers (not your thumb), try to find your pulse. There are several places you can check. 2. Once you have found a good pulse point, have a partner time you for 15 seconds and count the number of times you feel your pulse. ___________ 3. Multiply that number by 4 to get the resting beats per minute _____________ The Circulatory System • Made up of the cardiovascular system and the lymphatic system The Cardiovascular System • Made up of (organs): – heart – blood vessels (veins and arteries) – blood The Cardiovascular System • Functions – Carries nutrients, gases, hormones and waste around the body. • carbon dioxide and waste away • oxygen, nutrients, and hormones to – Helps your body maintain a balanced temperature. vocabulary word! • heart – hollow muscular organ that pumps blood around the body. • Size of your fist • Located in the center of your chest • right side pumps oxygen poor blood to the lungs • left side pumps oxygen rich blood to the body. Structure of the Heart • The heart has two sides • Each side has an upper chamber – Atrium • Each side has a lower chamber – Ventricle How the Heart Works • The heart’s action has two phases – The heart relaxes and the atria fill with blood – The atria contract, blood is pumped into the ventricles, then the ventricles contract and send blood out of the heart • Blood only travels in one direction, it cannot flow backwards Regulation of the Heartbeat • The heart contains pacemaker cells that tell the heart when to beat – When you are exercising, excited, scared etc…, your heart beats faster. – When you are relaxed, calm, asleep etc…, your heart beats slower. vocabulary word! • blood – the tissue that carries gases, hormones, nutrients and wastes through the body. • Helps the body maintain homeostasis (balance) FACT: blood is NEVER blue!!!! Oxygen rich blood from an artery Oxygen poor blood from a vein Unless you’re a horseshoe crab. vocabulary word! • blood vessels – the tubes that your blood travels in. – arteries – capillaries – veins vocabulary word! Arteries • arteries - carry oxygen rich blood away from the heart. – Walls are thick, strong and flexible – Contain smooth muscle that can contract and relax Arteries vocabulary word! Capillaries • capillaries - tiny blood vessels where material is exchanged between the blood and the body’s cells. • Oxygen and glucose rich blood from the arteries goes into the capillaries • From the capillaries needed materials pass into the cells and waste material is removed from the cells Capillaries vocabulary word! Veins • veins - carry oxygen poor blood back to the heart. – Veins have 3 layers to their walls too but the wall is much thinner – Muscle contractions, breathing and valves help move blood through veins Veins Create this chart in your notes and complete. artery capillary Blood moves in circuits inside blood vessels. • Oxygen poor blood enters the right atrium. • It is then pumped to the right ventricle, then to the lungs. • It picks up oxygen and goes back to the left atrium • It pumps from the left atrium into the left ventricle. • The left ventricle pumps oxygen rich blood to the rest of the body. Blood moves in two circuits around the body: Maintaining body temperature • Blood circulating through the body helps maintain homeostasis. • When we are hot, blood vessels enlarge to allow more blood close to the surface of our skin where it can be cooled. • When we are cold, blood vessels constrict to keep as much blood close to the chest as possible to keep us warm. The Lymphatic System • Made up of (organs): – lymph nodes – lymph vessels – lymph – spleen – bone marrow – Tonsils – thymus The Lymphatic System • Functions – Carries white blood cells. – Helps remove waste from the blood. – Helps us heal and fight disease. vocabulary word! • lymph – clear to white fluid found in blood that contains white blood cells. • Lymph can move in and out of blood vessels and body tissues. • It helps prevent infection and heals injuries. • lymph nodes – small, bean shaped organs that remove dead cells and pathogens. • Found mostly in the arm pits, neck and groin. • Stores white blood cells that help fight infection. • bone marrow – soft tissue inside of bones where red blood cells are produced. • tonsils – small lymphatic organs at the back of the throat. • Tonsils help defend the body against infection. • spleen – largest lymphatic organ. It stores white blood cells. Working together: • These two systems work together to form the circulatory system. • Blood stays in the blood vessels (closed loop). • Lymph can travel in and out of lymph vessels and into and out of blood vessels (open loop). Working together: Working together: