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17 Cards in this Set
- Front
- Back
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Primary function of circulatory system
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Transport necessary materials to all the cells of an animal’s body
Transport waste products away from the cells where they can be released into the environment |
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3 types of circulatory systems
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Gastrovascular cavities
Open systems Closed systems |
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Gastrovascular Cavities
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Body cavity with a single opening to the outside
Cnidarians (jellyfish, sea anemones and hydras) Food is digested in the cavity and absorbed by body cells Wastes are excreted into the cavity |
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Open Circulatory Systems
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Arthropods and some mollusks
Basic components Hemolymph Mixes directly with interstitial fluid Vessels One or more hearts Vessels open into animal’s body cavity |
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Limitations
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hemolymph cannot be selectively delivered to different tissues
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Closed Circulatory Systems
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Blood and interstitial fluid are physically separated
Differ in components and chemical composition Larger, more active animals need a higher pressure to pump blood to all body cells Found in earthworms, cephalopods, and all vertebrates |
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CCC also...
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Can be adjusted to match the animal’s metabolic demands
Capacity to heal themselves when wounded (clots) |
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CCC also...
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Advantages
Animal can grow larger with more efficient supply Blood flow can be selectively controlled 2 major groups Single circulation – fish Double circulation – crocodiles, birds, and mammals Amphibians and most reptiles have systems with features of both |
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Single Circulation
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Single atrium collects blood from tissues
Single ventricle pumps blood out of the heart Arteries carry blood away from the heart to the gills Blood picks up oxygen and drops off carbon dioxide and goes on through arteries to other body tissues |
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Intermediate circulatory features
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Amphibians and most reptiles
Amphibians rely on lungs and highly permeable skin to obtain oxygen and get rid of carbon dioxide Heart pumps blood to either (simultaneously) Pulmocutaneous circulation – respiratory surfaces of lungs and skin Systemic circulation – body tissues |
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Double Circulation
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Crocodiles, birds and mammals
Oxygenated and deoxygenated blood separates into 2 distinct circuits Systemic circulation – to the body Pulmonary circulation – to the lungs 2 atria and 2 ventricles |
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Blood
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Fluid connective tissue
Cells and cell fragments Solution of water containing dissolved nutrients, proteins, gases, and other molecules |
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4 components of blood
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Plasma – water and solutes
Functions in buffering, water balance and immune cell transport Leukocytes – white blood cells Defend body against infection and disease Erythrocytes – red blood cells Oxygen transport using hemoglobin Platelets or thrombocytes Role in formation of blood clots (fibrin precipitation) |
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Vertebrate Heart
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Septum separates atria and ventricles
Blood enters from systemic or pulmonary veins into atrium Through one-way atrioventricular (AV) valves into ventricles Out one-way semilunar valves into aorta (systemic) or pulmonary arteries |
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Myongenic Hearts
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Neurogenic hearts of arthropods require regular electrical impulses from the nervous system
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Cardiac Cycle
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Events that produce a single heartbeat
2 phases Diastole – atria contract and ventricles fill (blood pressure lowest) Systole – ventricles contract and blood is ejected from the heart (blood pressure highest) |
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Cardiac Output
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Amount of blood the heart pumps per unit time in Liters/minute
Depends on size of the heart and how often it beats Stroke volume – amount of blood a heart ejects at each beat |
