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The Circulatory System. Learning Goals. I know the structure and function of the circulatory system. I know the diseases and disorders of the circulatory system. I understand the blood flow and parts of the heart. . Circulatory System. A transport system that has four main functions:
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Learning Goals • I know the structure and function of the circulatory system. • I know the diseases and disorders of the circulatory system. • I understand the blood flow and parts of the heart.
Circulatory System A transport system that has four main functions: • Transport oxygen and carbon dioxide to and from the cells of the body • Transport nutrients to cells and waste from the cells • Transport hormones throughout the body • Maintain body temperature
Three Main Components • The pump – the heart • Fluid – the blood 3. Blood vessels (arteries, veins and capillaries)
THE HEART • Size of your first • Pumps blood through vessels • 4 chambers (2 atria and 2 ventricles) • Thick muscular walls – The left side of the heart is more muscular than the right. Why? • Controlled by electric signals from the brain • Sinoatrial node (SA node) is the pacemaker of the heart.
BLOOD The Components of Blood: • Plasma - 55% of the blood volume - 92% of plasma is water, the rest contains minerals (sugar, protein, fat, salts) 2. Red Blood Cells - has hemoglobin (red) - Carries oxygen to the cells - No nucleus 3. White Blood Cells – Carried to infected tissues to fight bacteria and virus’ 4. Platelets – cell fragments (no nucleus) that help clot the blood.
BLOOD VESSELS 3 Types: • Arteries – Largest vessels - Carry blood away from the heart - Have thick muscular walls * The largest artery is the aorta 2. Veins – Thinner muscular walls - Carry blood back to the heart - Valves to prevent backflow
Blood Vessels Continued 3. Capillaries – Smallest blood vessels - Site of gas exchange between blood and cells (diffusion) - Connect arteries and veins
Atherosclerosis • Artery wall thickens as a result of the accumulation of fatty materials such as cholesterol • Caused by damage to the innermost layer of the artery: - High levels of cholesterol and fat in the blood. - High Blood Pressure - Cigarette Smoke • Wall thickens artery diameter gets smaller less blood flow decreases oxygen circulation. • Blood clot can form. If it cuts off oxygen supply to the brain – stroke. If it cuts off oxygen supply to the heart – heart attack.
Varicose Veins • Swollen, twisted and sometimes painful veins filled with an abnormal collection of blood. • Causes – Valves do not function properly, allowing blood to stay in the vein. Blood pools and causes swelling. • Standing for a long time can lead to varicose veins. Why? • Treatment – Avoid standing for too long, raise your legs, wear elastic support pressure stockings. - Surgery: Vein Stripping removes the varicose veins in the legs. Usually only if severe pain or skin sores. - Sclerotherapy: Medicine is injected into the veins, which make them shrink. Less invasive, improves appearance.
Summary • The circulatory system is a transport system that is made up of the blood, the heart, and the blood vessels. • It’s function is to move oxygen and nutrients to the cells of the body and remove carbon dioxide and wastes. • Heart disease is the group of conditions that affect the functioning of the heart. • Angiograms and electrocardiograms are important technologies that help diagnose abnormalities in the circulatory system.
Homework • Page 87 #3, 4, 5, 7 and 8
THE CIRCULATORY SYSTEM (Part II)
Learning Goal • I understand the blood flow and parts of the heart.
Heart Rate Activity Heart Rate – The number of beats per minute (bpm) 1. Take your resting heart rate (neck next to your windpipe or wrist). Count the beats for 15 seconds than times that by 4 - Should be between 60-100 2. Do jumping jacks for 2 minutes. Take your heart rate again. Why did we see these results?
Let’s Take a Look at the Blood Flow through the Heart YouTube clip: Blood Flow through The Heart http://www.youtube.com/watch?v=Rj_qD0SEGGk