THE CIRCULATORY SYSTEM: OVERVIEW AND THE HEART

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1 THE CIRCULATORY SYSTEM: OVERVIEW AND THE HEART WHAT IS IT? The circulatory system is the WHAT NEEDS TO BE TRANSPORTED? As you have already learned, your tissues require (proteins, lipids and carbs) which are broken down and absorbed into the blood in the digestive system. These allow cells to grow, function and derive energy. Deriving energy requires one other essential ingredient;. The body derives its energy from a process called cellular respiration. The overall formula for cellular respirations is: Oxygen + Glucose Energy + Carbon dioxide + Water Ultimately, every cell in your body needs to receive and and must remove. FOUR MAIN FUNCTIONS OF THE CIRCULATORY SYSTEM? 1) 2) 3) 4) CIRCULATORY SYSTEM OVERVIEW The hearts pumps deoxygenated blood to the lungs Blood is oxygenated in the lungs The heart pumps oxygenated blood to the body through arteries Deoxygenated Blood returns to the heart through veins The body uses oxygen

2 THE HEART The heart is a large, powerful muscle. When it relaxes it fills with blood. This process of relaxing and filling is called. When it contracts it pumps blood to the lungs and body. This process of contracting and pumping is called. Your heart contracts TWICE to complete one full heartbeat. This means that the heart actually uses a. Pump #1 - Pump #2 - Heart Chamber Right atrium Left atrium Right Ventricle Left Ventricle Chamber Thickness Chamber Strength Reason(s)

3 HEART VALVES When the ventricles contract, why would blood only flow to the heart and body? If there is an opening for blood to enter the ventricles from the atria, shouldn t some of the blood flow back into the atria? It is the valves between the atria and ventricles that prevent the of blood. Sketch a valve to show how it keeps blood moving in one direction Each time the heart pumps blood flows through the veins toward the heart. This opens the valves When the heart relaxes between pumps, to prevent blood from flowing backwards by gravity, the valves close due to back pressure Other than between atria and ventricles, where else are the valves inside the heart? 1) 2) Why does the heart need valves? BLOOD PRESSURE Blood pressure is the force of blood pushing on the walls of the arteries. It is measured using a sphygmomanometer which reads two numbers. 1) Systolic pressure - 2) Diastolic pressure - The average healthy blood pressure for adults is approximate 120 / 80 (spoken 120 over 80). This means that the systolic pressure is 120 mm Hg and the diastolic pressure is 80 mm of Hg. Your resting blood pressure is an important indicator of health. What are some typical causes of hypertension (high blood pressure)?

4 Using today s lesson and the diagram to the left, write out the complete procedure for how blood flows through the heart. Name all of the parts involved. Use the following terms where applicable: right atrium, left atrium, right ventricle, left ventricle, pulmonary artery, pulmonary vein, vena cava, aorta, valve, artery, vein, diastole, systole. 1) During diastole, the right atrium relaxes and fills with deoxygenated blood from the vena cava. 2) During systole, deoxygenated blood is pumped into the right ventricle from the right atrium. 3) 4) 5) 6) 7) 8) 9) 10)

5 THE CIRCULATORY SYSTEM: BLOOD VESSELS + BLOOD ARTERIES AND VEINS There are two types of blood vessels Arteries - Veins - The only exception to this rule in the body is in the pulmonary system: Pulmonary artery - Pulmonary vein - VALVES IN VEINS The pumping of the heart is far from the veins meaning that blood pressure in veins is at its lowest. Often blood also needs to work against gravity to return to the heart. To prevent the backflow of blood, there are valves in the veins. Sketch a diagram of how valves in the veins work. Each time the heart pumps blood flows through the veins toward the heart. This opens the valves When the heart relaxes between pumps, to prevent blood from flowing backwards by gravity, the valves close due to back pressure CAPILLARIES Arteries are thick and muscular to help push large amounts of blood around while maintaining the blood pressure. This means that it is difficult for oxygen and nutrients to enter or leave the blood through arteries. Arteries branch off into networks of extremely thin vessels to deliver nutrients and oxygen and take in wastes like carbon dioxide. These networks are called.

6 THE CIRCULATORY SYSTEM: BLOOD VESSELS + BLOOD ARTERIES AND VEINS There are two types of blood vessels Arteries - Veins - The only exception to this rule in the body is in the pulmonary system: Pulmonary artery - Pulmonary vein - VALVES IN VEINS The pumping of the heart is far from the veins meaning that blood pressure in veins is at its lowest. Often blood also needs to work against gravity to return to the heart. To prevent the backflow of blood, there are valves in the veins. Sketch a diagram of how valves in the veins work. Each time the heart pumps blood flows through the veins toward the heart. This opens the valves When the heart relaxes between pumps, to prevent blood from flowing backwards by gravity, the valves close due to back pressure CAPILLARIES Arteries are thick and muscular to help push large amounts of blood around while maintaining the blood pressure. This means that it is difficult for oxygen and nutrients to enter or leave the blood through arteries. Arteries branch off into networks of extremely thin vessels to deliver nutrients and oxygen and take in wastes like carbon dioxide. These networks are called.

7 BLOOD Blood component Function Plasma Red Blood Cells White Blood Cells Platelets

8 BLOOD Blood component Plasma Red Blood Cells White Blood Cells Platelets Function The fluid through which the solid components and dissolved gases, nutrients, wastes and hormones are transported around the body Contain hemoglobin which carries oxygen to the body Protect the body against infection (invading microorganisms and toxins) Involved in blood clotting