Chapter 32 Circulation Lecture Outlines by Gregory Ahearn University of North Florida Copyright 2011 Pearson Education Inc Chapter 32 At a Glance 32 1 What Are the Major Features and Functions of Circulatory Systems 32 2 How Does the Vertebrate Heart Work 32 3 What Is Blood 32 4 What Are the Types and Functions of Blood Vessels 32 5 How Does the Lymphatic System Work with the Circulatory System Biology Life on Earth 9e Copyright 2011 Pearson Education Inc 32 1 What Are the Major Features and Functions of Circulatory Systems All circulatory systems have three major parts A pump the heart that keeps the blood circulating transport A liquid blood that serves as a medium of A system of tubes blood vessels that conduct the blood throughout the body Biology Life on Earth 9e Copyright 2011 Pearson Education Inc 32 1 What Are the Major Features and Functions of Circulatory Systems Two types of circulatory systems are found in animals Open circulatory systems are found in many invertebrates including arthropods and mollusks These animals have one or more simple hearts a network of vessels and series of interconnected spaces within the body called a hemocoel Tissues and organs in the hemocoel are bathed by a fluid called hemolymph which acts as both blood and the extracellular fluid that bathes all cells Biology Life on Earth 9e Copyright 2011 Pearson Education Inc 32 1 What Are the Major Features and Functions of Circulatory Systems Open circulatory systems are found in many invertebrates including arthropods and mollusks continued In insects the heart is a modified blood vessel with a series of contracting chambers When the chambers contract valves in the heart are pressed shut forcing the hemolymph out through vessels and into hemocoel spaces throughout the body When the chambers relax blood is drawn back into them from the hemocoel Biology Life on Earth 9e Copyright 2011 Pearson Education Inc Author Animation Open Circulatory Systems Biology Life on Earth 9e Copyright 2011 Pearson Education Inc 32 1 What Are the Major Features and Functions of Circulatory Systems Two types of circulatory systems are found in animals continued Closed circulatory systems are present in some invertebrates including the earthworm and very active mollusks such as squid and octopuses and in all vertebrates including humans In these systems blood is confined to the heart and blood vessels which branch throughout the organs and tissues of the body Closed systems allow more rapid blood flow more efficient transport of dissolved substances and higher blood pressure than is possible in open systems Biology Life on Earth 9e Copyright 2011 Pearson Education Inc Author Animation Closed Circulatory Systems Biology Life on Earth 9e Copyright 2011 Pearson Education Inc Open and Closed Circulatory Systems vessel heart heart valves vessels hemocoel openings with valves tubular hearts hemolymph in the hemocoel bathes the internal organs a Open circulatory system blood vessel heart extracellular fluid hearts dorsal blood vessel blood vessels branch in each organ b Closed circulatory system ventral blood vessel small blood vessels Fig 32 1 Biology Life on Earth 9e Copyright 2011 Pearson Education Inc 32 1 What Are the Major Features and Functions of Circulatory Systems The vertebrate circulatory system of humans and other vertebrates has diverse functions Transport of O2 from the lungs or gills to the tissues and transport of CO2 from the tissues to the lungs or gills Distribution of nutrients from the digestive system to all body cells Transport of waste products and toxic substances to the liver where many of them are detoxified and to the kidneys for excretion Biology Life on Earth 9e Copyright 2011 Pearson Education Inc 32 1 What Are the Major Features and Functions of Circulatory Systems The vertebrate circulatory system of humans and other vertebrates has diverse functions continued Distribution of hormones from the glands and organs that produce them to the tissues on which they act Regulation of body temperature by adjustments in blood flow Wound healing and blood clotting to prevent blood loss Protection against disease by circulating white blood cells and antibodies Biology Life on Earth 9e Copyright 2011 Pearson Education Inc 32 2 How Does the Vertebrate Heart Work The vertebrate heart consists of muscular chambers capable of strong contractions Chambers called atria collect blood Atrial contractions send blood into ventricles chambers whose contractions circulate blood through the lungs and to the rest of the body Biology Life on Earth 9e Copyright 2011 Pearson Education Inc 32 2 How Does the Vertebrate Heart Work Four chambered hearts consist of two separate pumps In each pump an atrium collects the blood before passing it to a ventricle that propels it into the body One pump consisting of the right atrium and right ventricle deals with deoxygenated blood Oxygen depleted blood enters the right atrium through two large veins vessels that carry blood toward the heart called the superior and inferior vena cava After filling with blood the right atrium contracts forcing blood into the right ventricle Contraction of the right ventricle sends the oxygen depleted blood to the lungs through the pulmonary arteries vessels that carry blood away from the heart Biology Life on Earth 9e Copyright 2011 Pearson Education Inc 32 2 How Does the Vertebrate Heart Work Four chambered hearts consist of two separate pumps continued The other pump consisting of the left atrium and left ventricle deals with oxygenated blood Oxygen rich blood from the lungs enters the left atrium through the pulmonary veins and is then squeezed into the left ventricle Contraction of the left ventricle sends the oxygenated blood through the aorta to the rest of the body Biology Life on Earth 9e Copyright 2011 Pearson Education Inc 32 2 How Does the Vertebrate Heart Work Valves maintain the direction of blood flow When the ventricles contract blood must be prevented from flowing back into the atria Blood entering the arteries must also be prevented from flowing back into the ventricles as the heart relaxes The directionality of blood flow is maintained by one way valves Pressure in one direction opens them easily but reverse pressure forces them closed Biology Life on Earth 9e Copyright 2011 Pearson Education Inc 32 2 How Does the Vertebrate Heart Work Valves maintain the direction of blood flow continued Atrioventricular valves allow blood to flow
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