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Unformatted text preview: Internal Transport Chapter 43 KEY CONCEPTS • A circulatory system typically consists of blood, a heart, and a system of blood vessels or spaces through which blood circulates Learning Objective 1 • Compare and contrast internal transport in animals with no circulatory system, those with an open circulatory system, and those with a closed circulatory system Internal Transport • Diffusion • Molecule can diffuse 1um in less than 1 msec – so diffusion is adequate over microscopic distances • in small, simple invertebrates (sponges, cnidarians, flatworms) • Specialized circulatory systems • Where transport is necessary over many cell thickness • in larger animals • blood, heart, blood vessels or spaces No Circulatory System (Fig 43-1) • Interstitial Fluid: • Tissue fluid between cells in all animals • Brings oxygen, nutrients in contact with cells • Circulatory system for efficient distribution of materials: • Blood – cells and cell fragments • Heart – pumps blood • Blood vessels – circulatory system Open Circulatory System • Found in arthropods, most mollusks • Blood and interstitial fluid is indistinguishable and called hemolymph: which spills out of blood vessels into sinuses • Blood flows into a hemocoel or body cavity • bathing tissues directly • Reenters circulatory system through openings in heart (arthropods) or open-ended vessels that lead to gills (molluscks) Open Circulatory Systems (Fig 43-2) Closed Circulatory System • Found in some invertebrates: annelids, cephalopods and echinoderms • Proboscis worms have no heart - rely on movement and contractions of large blood vessels • Blood flows through a continuous circuit of blood vessels Closed Circulatory System (Fig 43-3) KEY CONCEPTS • Arthropods and most mollusks have an open circulatory system in which blood bathes the tissues directly • Some invertebrates and all vertebrates have a closed circulatory system in which blood flows through a continuous circuit of blood vessels Vertebrate Circulatory System 1 • Muscular heart • pumps blood into arteries, capillaries, veins • Transports • nutrients, oxygen, metabolic wastes, hormones • Helps maintain • fluid balance, pH, body temperature • Defends body against disease Learning Objective 2 • Compare the structure and function of plasma, red blood cells, white blood cells, and platelets Plasma • Water and salts • Substances in transport: • as blood passes through capillaries – substances continuously move in and out • Plasma proteins • Albumins: • regulates distribution of fluid between plasma and interstitial fluid; maintains osmotic pressure, maintains pH as an acid-base buffer • Globulins: • Alpha: hormones, binding proteins, prothrombin and HDL (carries fats and cholesterol) • Beta: other lipoproteins, binding proteins (vitamins and minerals) • Gamma: antibodies • Fibrinogen: clotting protein that if removed = serum Red Blood Cells (Erythrocytes)...
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This note was uploaded on 10/08/2010 for the course BIO 380 taught by Professor Martin during the Spring '10 term at Rutgers.
- Spring '10