Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Circulatory System Circulation • Distribution of needed compounds to each cell in the body • Diffusion is not sufficient to do this. • As organisms grew bigger the method of distribution had to change to accommodate distribution Types of system • Open • Fluid not in continue vessels • Blood pools • Limits size of organism. • Closed Functions of vertebrate circulatory system • Nutrient and waste transport • Nutrients are picked up in the small intestine and delivered to the rest of the body. • Wastes are then picked up and passed through the liver and the kidney to be removed. • Oxygen is picked up in the gills or lungs by the hemoglobin in the Red Blood Cells and carried to all functioning cells • There it diffuses into each cell and picks up Carbon dioxide that will eventually removed as a waste product Functions continued • Temperature regulation • Blood flow can be directed to different areas of body to help with temperature control • Hormone delivery • Hormones and other regulatory materials are delivered through the circulatory system. • Immune system materials transported Vessels • ARTERIES • Carry blood away from the heart • Lined with smooth muscle • Able to contract and expand with the flow of blood • ARTERIOLES • Smallest arteries can adjust to blood flow • Narrows the flow of blood Capillaries • Smallest vessels • Usually no more than 1mm long. • Blood flow is narrowed so that RBC’s are single file • BP forces fluid out of the blood at arteriole end to make the blood more concentrated • Exchange of materials can happen more efficiently in concentrated blood. • Water move back in near the veinule end of capillary • Excess water is drained by the lymphatic system Veins • Carry blood back to the heart • Have one way valves to help keep blood from backflow • Veinules (smallest veins) empty into veins which empty into vena cava and then the heart • Blow flow is aided by skeletal muscle in the extremities Heart • Four chambers • Four valves • Right side deoxygenated blood leads to pulmonary circulation. • Left side oxygenated blood leads to systemic circulation • Left side is stronger Path of blood through the heart • Inferior, superior vena cava-right atriumtricuspid valve-right ventricle-pulmonary semilunar valve-pulmonary arteries-lungspulmonary veins-left atrium-bicuspid valve-left ventricle-aortic semi-lunar valve-aorta-rest of body Coronary arteries • Small coronary arteries feed the heart muscle • If blood flow through these arteries is blocked it can cause a heart attack Control of the heart beat • Heartbeat does not need nerves to happen • Nerves can effect the rate of the beat • Beat is regulated by the sinoatrial node. This is a group of cells in the right atrium • The ventricles must contract lightly after the atrium • The AV node delays the contraction by 0.1 seconds Heart Sounds • Heart sounds occur when the blood hits the valves as they close. • The “lub” sound is when the blood hits the avvalves (cuspids) • The “dub” sound is made when the blood hits the semi-lunar valves Cardiac output • Stroke volume is the amount of blood pumped per beat • Heart rate is the number of beats per minute. • CO=HR X SV • Normally about 5L per minute • An increase in either HR or SV will increase CO • A healthy heart will beat less and have a higher stroke volume Oxygen • Whole blood can carry 240 ml of Oxygen/Liter • Hemoglobin is most important • Oxygen is picked in lungs and carried to rest of body • About 25 % is diffused at rest • Body keeps 4-5 minutes in reserve Blood • AVG. person has 5L of blood • Plasma 55% of blood-fluid part of blood that carries a variety of dissolved substances • This includes gases, glucose, hormones and waste products • Also carries proteins • Albumen-carries lipids • Fibrinogens-clotting Blood continued • Cells 45% of blood • Red Blood Cells (RBC) (erythrocytes) • 1ml blood= 5 million RBC’s • Continuously made in the marrow • Shaped like biconcave disk to increase surface area for exchange • Lack nucleus for more space for hemoglobin • Live for about 4 months • Glycoproteins on surface create different blood types Blood continued • White blood cells (WBC’s) (leukocytes) • Less than 1% of cells in blood • Part of immune system • Platelets • Important to • Platelets stick to wounded area • Cause fibrinogen to become fibrin and create clot blood clotting Heart Disease • Heart attack • Blocked coronary arteries • Atherosclerosis • Plaque deposits on the arterial walls • Peripheral vascular disease • High blood pressure