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Chapter 42: Circulation. By Lauren Shevchek and Nonye Enogwe. Circulation…. t he continuous motion by which blood travels through all parts of the body under the action of the heart Helps with the transportation of blood throughout the body Regulates the .
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Chapter 42: Circulation By Lauren Shevchek and NonyeEnogwe
Circulation…. the continuous motion by which blood travels through all parts of the body under the action of the heart • Helps with the transportation of blood throughout the body • Regulates the
Different forms of circulatory sytstems… • Closed circularory system • Open circulatory system -Circulatory fluid (blood) -Set of tubes (blood vessels) -Muscular pump (heart) • Gastrovascular cavity
Vertebrate Circulatory System • Blood: used to carry dissolved materials and cells • Blood vessels: carries materials and allows for exchange through the body • Heart: muscle that moves blood in a distinct direction
Fish Amphibians Mammals Amphibians have a three-chambered heart and two circuits of blood flow: pulmocutaneousand systemic. With double circulation, blood is delivered to systemic organs under high pressure. There is some mixing of oxygen-rich and oxygen-poor blood within the single ventricle. Mammals have a four-chambered heart and double circulation. Inside of the heart, oxygen-rich blood is kept separated from oxygen-poor blood. Fish have a two-chambered heart and a single circuit of blood flow
Pulmonary & Systemic • lead to capillaries in the gas-exchange organs • Where most of the returning oxygen-rich blood is pumped into
Double Circulation Advantages over single circulation • no mixing of the oxygenated and deoxygenated blood • blood is pumped to the rest of the body with a higher concentration of oxygen
Cardiac Cycle the alternating contractions and relaxations of the heart • Systole • Diatole
Cardiac Output Main two factors • Heart rate • Stroke volume
Abnormal heart Heart Murmur: an abnormal sound of the heart; sometimes a sign of abnormal function of the heart valves
SA Node • As nerves become more sympathetic, heart rate goes up and when it becomes parasympathetic the heart rate goes • Hormones secreted into the blood by glands influence the pacemaker like epinephrine (“fight-or-flight” hormone from the adrenal glands) which increases heart rate • As temperature increases, the rate of the pacemaker also increases and vise versa • Exercise increases heart rate, an adaptation which allows the circulatory system to provide extra oxygen needed by the muscles hard at work a small body of specialized muscle tissue located in the wall of the right atrium of the heart that acts as a pacemaker by producing a contractile signal at regular intervals