Circulatory System

The circulatory system is made up of the heart, blood, and all the various types of blood vessels such as arteries, veins, and capillaries. The job of the circulatory system is to transport oxygen and nutrients throughout the body and help bring waste materials from the cells so the body can dispose of them. Watch BrainPop Circulatory System

Watch BrainPOP Circulatory System as an intro

Blood is circulated throughout the body in different types of blood vessels: Arteries Arteries are blood vessels that carry blood AWAY from the heart. Remember, A A Arteries Away, A A Arteries Away, A A Arteries Away. Capillaries Capillaries are tiny blood vessels as thin or thinner than the hairs on your head. Capillaries connect arteries to veins. Food substances, (nutrients), oxygen and wastes pass in and out of your blood through the capillary walls. Veins Veins carry blood back toward your heart.

The human heart has four chambers: a left and right atrium and a left and right ventricle (this is facing the heart as it would appear in a person.) Remember “a” for atrium, “a” for above. The heart is the center of the circulatory system.

Between each chamber of the heart are one-way valves that the blood flows through.

Contractions of the heart muscle pump blood through these four chambers. Let’s watch a video to see the path of blood as it travels to, in, and from the heart…. topics/topics/hhw/contraction.html ed

Deoxygenated blood enters the heart via the vena cava into the right atrium. The blood then flows through a special valve (tricuspid) into the right ventricle. The T valve prevents the blood from flowing backward. The heart then pumps the blood into the branching pulmonary artery. One branch goes to the left lung, one to the right lung. The pulmonary artery is the only artery in the body that carries deoxygenated blood. The blood then enters the capillaries inside the lungs. As it passes over and through the alveoli, waste CO 2 is released and oxygen is absorbed. Let’s take a look at that again….

Once the blood is reoxygenated, the pulmonary veins return the blood to the heart, into the left atrium this time. The blood flows into the left ventricle, the most powerful pumping section in the heart because it must send blood out to the whole body. The blood leaves the top of the heart by way of the largest artery in the body, the aorta. Some of the blood passes three arteries located along the top of the Arch of the Aorta, while the rest loops down behind the heart down into the rest of the body. It enters smaller arteries called arterioles and then capillaries.

1.Which structure(s) is/are the Vena Cava? 2.Which structure is the aorta? 3.Which structure(s) are the pulmonary arteries? 4.Which structures are the pulmonary veins? Vena Cava Aorta Pulmonary Artery Pulmonary Vein

1.Which structure(s) is/are the Vena Cava? 2.Which structure is the aorta? 3.Which structure(s) are the pulmonary arteries? 4.Which structures are the pulmonary veins? Vena Cava Aorta Pulmonary Artery Pulmonary Vein

1.Which structure is the left atrium? 2.Which structure is the right ventricle? 3.Which structure is the left ventricle? 4.Which structure is the right atrium?

1.Which structure is the left atrium? 2.Which structure(s) are the vena cava? 3.Which structure is the right ventricle? 4.Which structure is the pulmonary vein? 5.Which structure is the left ventricle? 6.Which structure is the pulmonary artery? 7.Which structure is the right atrium? 8.Which structure is the aorta? Vena Cava Pulmonary Artery Aorta Pulmonary Vein Vena Cava Pulmonary Artery

1.Point to the blood vessel through which blood returns to the heart from the rest of the body. What is this blood vessel called? The Vena Cava 2. Where does the blood go next? What is this chamber called? The right atrium. 3. Next? What is this chamber called? The right ventricle. 4. Next? What is this blood vessel called? The pulmonary artery. 5. Where does this structure take the blood? To the lungs. 6. Show the blood vessel(s) through which blood returns to the heart from the lungs? What are these blood vessels called? The pulmonary veins. 7. Next? What chamber? The left atrium. 8. Next? What chamber? The left ventricle 9. Then finally out of the heart where? Vessel? Aorta.

1.Point to the blood vessel through which blood returns to the heart from the rest of the body. What is this blood vessel called? The Vena Cava 2. Where does the blood go next? What is this chamber called? The right atrium. 3. Next? What is this chamber called? The right ventricle. 4. Next? What is this blood vessel called? The pulmonary artery. 5. Where does this structure take the blood? To the lungs. 6. Show the blood vessel(s) through which blood returns to the heart from the lungs? What are these blood vessels called? The pulmonary veins. 7. Next? What chamber? The left atrium. 8. Next? What chamber? The left ventricle 9. Then finally out of the heart where? Vessel? Aorta.

On the worksheet, label the major arteries and veins of the heart and draw arrows and label the direction of blood flow through the heart.

Cow heart

Diseases of the Circulatory System 1.Atherosclerosis- the build up of various fatty substances, calcium, cellular waste products, and other substances on the insides of our arteries. This conglomerate of substances is known as plaque. Atherosclerosis results in decreased blood flow, higher blood pressure. Both of these are high risk factors for heart attack or stroke.

2. Myocardial Infarction (Heart Attack)- a situation where the oxygen supply to the heart is cut off. This causes sections of heart muscle to stop functioning. If serious enough, this can lead to death.

3. Stroke- a situation where the oxygen supply to the brain is cut off. Strokes can result in paralysis on one half of the body (usually the left), loss of speech, impaired cognitive (thinking) abilities, and death.

4. Hypertension (high blood pressure)- a situation where the blood pressure on the walls of our blood vessels is too high. HBP can lead to stroke or heart attack if left untreated.

The Components of Blood Watch BrainPop Blood Red Blood Cells Red Blood Cells are responsible for carrying oxygen to the cells and carbon dioxide away from the cells. Red blood cells contain a protein called hemoglobin which binds with oxygen. RBCs pick up oxygen in the lungs and transport it to all the body cells. After delivering the oxygen to the cells it gathers up the carbon dioxide (a waste gas produced as our cells are working) and transports carbon dioxide back to the lungs where it is removed from the body when we exhale (breath out). There are about 5,000,000 Red Blood Cells in ONE drop of blood.

White Blood Cells (Germinators) White Blood Cells help the body fight off germs and infection. White Blood Cells attack and destroy pathogens when they enter the body. When you have an infection, your body will produce more White Blood Cells to help fight an infection. The white blood cells get additional help from other sources that are part of the body’s immune system. We’ll talk about that later.

White Blood Cells

Plasma Plasma is the liquid part of the blood. Approximately half of your blood is made of plasma. The plasma carries the blood cells and other components throughout the body.

Platelets Platelets are blood cells that help stop bleeding. When we cut ourselves we have broken a blood vessel and the blood leaks out. In order to plug up the holes where the blood is leaking from the platelets start to stick to the opening of the damaged blood vessels. As the platelets stick to the opening of the damaged vessel they attract more platelets, fibers and other blood cells to help form a plug to seal the broken blood vessel. When the platelet plug is completely formed the wound stops bleeding. We call our platelet plugs scabs.

Platelets actively clotting. They form a fibrous network that traps blood cells and helps the blood to clot.