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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.
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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 • in small, simple invertebrates (sponges, cnidarians, flatworms) • Specialized circulatory systems • in larger animals • blood, heart, blood vessels or spaces
Gastrovascular cavity Pharynx Mouth (b) Fig. 43-1b, p. 920
Interstitial Fluid • Tissue fluid between cells • in all animals • Brings oxygen, nutrients in contact with cells
Open Circulatory System • Found in arthropods, most mollusks • Blood flows into a hemocoel • bathing tissues directly
Stomach Ventricle Atrium Gills Fig. 43-2a, p. 921
Artery Ostia Tubular heart Fig. 43-2b, p. 921
Closed Circulatory System • Found in all vertebrates • and some invertebrates • Blood flows through a continuous circuit of blood vessels
Dorsal vessel Contractile blood vessels Ventral vessel Lateral vessels Fig. 43-3, p. 921
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, wastes, hormones
Vertebrate Circulatory System 2 • Helps maintain • fluid balance, pH, body temperature • Defends body against disease
Learn more about open and closed circulatory systems by clicking on the figures in ThomsonNOW.
KEY CONCEPTS • The vertebrate circulatory system transports nutrients, oxygen, wastes, and hormones; helps maintain fluid balance, appropriate pH, and body temperature; and defends the 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 • Plasma proteins • albumins • globulins • fibrinogen
Red Blood Cells(Erythrocytes) • Transport oxygen and carbon dioxide • Produce hemoglobin • red pigment that binds with oxygen
White Blood Cells (Leukocytes) • Defend body against disease organisms • Lymphocytes and monocytes • agranular white blood cells • Neutrophils, eosinophils, basophils • granular white blood cells
Platelets • Patch damaged blood vessels • Release substances essential for blood clotting
Whole blood Plasma Cell components Plasma proteins White blood cells (leukocytes) Lipo- proteins Albumins Globulins Fibrinogen Water Salts Dissolved gases Hormones Glucose Wastes 1 to 2 µm 7 µm Clotting proteins Red blood cells (erythrocytes) Platelets Agranular leukocytes Granular leukocytes Fig. 43-4a, p. 923
Learn more about the composition of vertebrate blood by clicking on the figures in ThomsonNOW.
Learning Objective 3 • What is the sequence of events involved in blood clotting?
Blood Clotting • Damaged cells and platelets • release substances that activate clotting factors • Prothrombin is converted to thrombin • converts fibrinogen to insoluble protein (fibrin) • Fibrin forms long threads • make up webbing of clot
1 Injury to blood vessel 2 Wall of vessel contracts 3 Platelets adhere to collagen fibers of damaged vessel wall 4 More permanent clot forms Platelet plug Blood flow decreases Blood flow decreases Blood flow Blood flow ceases Fig. 43-5a, p. 924
3. Platelets adhere to collagen fibers of damaged vessel wall 4. More permanent clot forms 1. Injury to blood vessel 2. Wall of vessel contracts Blood flow decreases Blood flow decreases Blood flow Blood flow ceases Platelet plug Stepped Art Fig. 43-5a, p. 924
Prothrombin Damaged cells and platelets release substances that activate clotting factors Prothrombin activator Ca2+ Fibrinogen Thrombin Ca2+ Fibrin threads (clot) Fig. 43-5b, p. 924
Learning Objective 4 • Compare the structure and function of different types of blood vessels, including arteries, arterioles, capillaries, and veins
Blood Vessels 1 • Arteries • carry blood away from the heart • Veins • return blood to the heart
Blood Vessels 2 • Arterioles • constrict (vasoconstriction) • dilate (vasodilation) • Arterioles regulate blood pressure and distribution of blood to tissues
Blood Vessels 3 • Capillaries • thin-walled exchange vessels • allow materials to transfer between blood and tissues
Vein Lymphatic Artery Venule Arteriole Capillary bed Lymph node Capillaries (a) Lymph capillaries Movement of interstitial fluid Fig. 43-6a, p. 926
Outer coat (connective tissue) VEIN Endothelium Smooth muscle ARTERY Outer coat (connective tissue) Endothelium CAPILLARY (b) Fig. 43-6b, p. 926
Precapillary sphincter Metarteriole True capillaries Venule Arteriole (a) Sphincters closed Fig. 43-7a, p. 927
Precapillary sphincter Metarteriole True capillaries Arteriole Venule (b) Sphincters open Fig. 43-7b, p. 927
Learning Objective 5 • Trace the evolution of the vertebrate cardiovascular system from fish to mammal
The Vertebrate Heart • One or two atria • receive blood • One or two ventricles • pump blood into arteries
The Fish Heart • One atrium and ventricle • single circuit of blood flow
Atrium Sinus venosus Veins from the body Valve Ventricle Aorta Valve (a) Fishes Fig. 43-8a, p. 928