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The Circulatory System. http://www.brightstorm.com/science/biology/the-human-body/circulatory-system/. The Circulatory System. A System of interconnected, one-way roads From superhighways to back alleys Allows the transport of materials from one place to another Hormones Oxygen
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The Circulatory System http://www.brightstorm.com/science/biology/the-human-body/circulatory-system/
The Circulatory System • A System of interconnected, one-way roads • From superhighways to back alleys • Allows the transport of materials from one place to another • Hormones • Oxygen • Cellular Wastes • Nutrients • Heart, Blood vessels, and Blood
The Heart • Consists mainly of cardiac muscle that pumps blood throughout the system • 4 Chambers • 2 upper Atria • 2 lower ventricles • Valves keep the blood flow going in only 1 direction http://www.youtube.com/watch?v=hCp4hVC2fnM
Heartbeat • Cardiac muscle contracts without stimulation by the nervous system • Specialized cardiac muscle cells send out electrical impulses that stimulate the contractions • Normally this all happens in perfect synchronization • http://www.nhlbi.nih.gov/health/health-topics/topics/hhw/electrical.html
Blood Vessels • Arteries – carry blood away from the heart • Thick walls that can withstand the pressure of the blood being pumped • Generally carry oxygen-rich blood • Largest is the aorta which receives blood directly from the heart • Veins – carry blood toward the heart • Lower pressure so the veins have valves that prevent backflow of deoxygenated blood • Larges is the inferior vena cava
Blood Vessels • Capillaries • Smallest of all the blood vessels • Connect very small arteries and veins • Exchange gases and other substances between cells and the blood • Very thin-walled
Blood Vessels and Homeostasis • Can either constrict (narrow) or dilate (get bigger) • These processes are signaled by the autonomic nervous system or the endocrine system • This process controls the amount of blood flowing to different organs
Blood Vessels and Blood Pressure • Highest in the arteries and lowest is the veins • When they take your blood pressure they are measuring the pressure in the arteries • High blood pressure = Hypertension • Can be controlled with diet, exercise and medication • http://www.healthcentral.com/high-blood-pressure/introduction-47-115.html
Cardiovascular Disease • Atherosclerosis • Build up of plaque on the insides of arteries • Debris, cholesterol, and other substances • High fat diet and smoking • Arteries narrow and blood flow is restricted http://www.youtube.com/watch?v=fLonh7ZesKs
Coronary Heart Disease • A heart attack occurs when the blood supply to a part of the heart muscle is blocked or shut off • Leading cause of death in adults in the US • Risks – smoking, lack of exercise, high-fat diet • Healthy life style choices reduce risk • Video: Heart Attack
Blood • A fluid connective tissue • Fluid part is called plasma • Contains many dissolved substances and blood cells • Red blood cells • White blood cells • Platelets • http://www.apan.net/meetings/busan03/materials/ws/education/demo-los/blood-rlo/whatisblood.swf
Blood • Red blood cells carry oxygen and contain hemoglobin a protein rich in iron that binds with oxygen • White blood cells are generally larger than red blood cells, but fewer in number • Part of the body’s defense system • Platelets – cell fragments involved in blood clotting – release clotting chemicals at the site of a wound
Blood Type • ABO blood groups • Rhesus blood type • Very important when we look at blood transfusions