Chapter © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC 5 NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Anatomy© Jonesand & Physiology Bartlett Learning, LLC of © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION the Cardiovascular System © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION OUTLINE Aortic arch: The second section of the aorta; it branches into Introduction the brachiocephalic trunk, left common carotid artery, and The Heart left subclavian artery. Structures of the Heart Aortic valve: Located at the base of the aorta, the aortic Conduction System© Jones & Bartlett Learning, LLCvalve has three cusps and opens© Jonesto allow blood & Bartlett to leave the Learning, LLC Functions of the HeartNOT FOR SALE OR DISTRIBUTIONleft ventricle during contraction.NOT FOR SALE OR DISTRIBUTION The Blood Vessels and Circulation Arteries: Elastic vessels able to carry blood away from the Blood Vessels heart under high pressure. Blood Pressure Arterioles: Subdivisions of arteries; they are thinner and have Blood Circulation muscles that are innervated by the sympathetic nervous Summary© Jones & Bartlett Learning, LLC system. © Jones & Bartlett Learning, LLC Atria: The upper chambers of the heart; they receive blood CriticalNOT Thinking FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Websites returning to the heart. Review Questions Atrioventricular node (AV node): A mass of specialized tissue located in the inferior interatrial septum beneath OBJECTIVES the endocardium; it provides the only normal conduction pathway between the atrial and ventricular syncytia. After reading this chapter, readers should be able to: © Jones & Bartlett Learning, LLC © JonesAV bundle: & Bartlett The bundle Learning, of His; a large LLCstructure that receives 1. Describe the organization of the cardiovascular the cardiac impulse from the distal AV node. It enters the NOT FOR SALEsystem OR DISTRIBUTIONand the heart. NOT FOR SALE OR DISTRIBUTION upper part of the interventricular septum. 2. Identify the layers of the heart wall. Blood volume: The sum of formed elements and plasma 3. Describe the general features of the heart. volumes in the vascular system; most adults have about 5 L 4. Answer the question of why the left ventricle is of blood. more muscular than the right ventricle. Capillaries: The smallest-diameter blood vessels, which 5. Describe the components© Jones and & Bartlettfunctions of Learning, the LLC © Jones & Bartlett Learning, LLC connect the smallest arterioles to the smallest venules. conducting systemNOT of FORthe heart. SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Cardiac conduction system: The initiation and distribution 6. Explain the events of the cardiac cycle. of impulses through the myocardium that coordinates the 7. Define cardiac output and stroke volume. cardiac cycle. 8. Distinguish among the types of blood vessels, their Cardiac cycle: A heartbeat; it consists of a complete series structures, and their functions. of systolic and diastolic events. 9.© JonesIdentify the & majorBartlett arteries Learning, and veins ofLLC the © Jones & Bartlett Learning, LLC Cardiac output: The volume discharged from the ventricle NOTpulmonary FOR SALEcircuit as OR well DISTRIBUTIONas the areas they serve. NOT FOR SALE OR DISTRIBUTION per minute, calculated by multiplying stroke volume by heart 10. Describe the hepatic portal system. rate, in beats per minute. Cardiac veins: Those veins that branch out and drain blood KEY TERMS from the myocardial capillaries to join the coronary sinus. © Jones & Aorta:Bartlett The largest Learning, artery in theLLC body, the aorta originates © JonesCarotid & sinuses: Bartlett Enlargements Learning, near theLLC base of the carotid from the left ventricle of the heart and extends down to the arteries that contain baroreceptors and help to control blood NOT FOR SALEabdomen, OR where DISTRIBUTION it branches off. NOT FORpressure. SALE OR DISTRIBUTION © Jones and Bartlett Publishers. NOT FOR SALE OR DISTRIBUTION 99069_ch05_6101.indd 35 2/3/12 2:08:58 PM 36 CHAPTER 5 Anatomy and Physiology of the Cardiovascular System © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALEKEY TERMS OR DISTRIBUTION CONTINUED NOTPulmonary FOR SALE valve: OR Lying DISTRIBUTION at the base of the pulmonary trunk, Cerebral arterial circle: The circle of Willis; it connects the this valve has three cusps and allows blood to leave the vertebral artery and internal carotid artery systems. right ventricle while preventing backflow into the ventricular Chordae tendineae: Strong fibers originating from the chamber. papillary muscles that attach to the cusps of the tricuspid Purkinje fibers: Consisting of branches of the AV bundle valve. © Jones & Bartlett Learning, LLCthat spread and enlarge, these© fibers Jones are located & Bartlett near the Learning, LLC papillary muscles; they continue to the heart’s apex and Coronary arteries: TheNOT first FORtwo aortic SALE branches, OR whichDISTRIBUTION NOT FOR SALE OR DISTRIBUTION supply blood to the heart tissues. cause the ventricular walls to contract in a twisting motion. Coronary sinus: An enlarged vein joining the cardiac veins; it Septum: A solid, wall-like structure that separates the left atria empties into the right atrium. and ventricle from the right atria and ventricle. Diastole: The relaxation of a heart structure. Sinoatrial node (SA node): A small mass of specialized Diastolic pressure: The lowest pressure that remains in the tissue just beneath the epicardium in the right atrium that © Jones & Bartlett Learning, LLC initiates impulses© Jones through & the Bartlett myocardium Learning, to stimulate LLC arteriesNOT beforeFOR the SALE next ventricular OR DISTRIBUTION contraction. NOT FOR SALE OR DISTRIBUTION Electrocardiogram (EKG): The recording of electrical contraction of cardiac muscle fibers. changes in the myocardium during the cardiac cycle. The Stroke volume: The volume of blood discharged from the EKG machine works by placing nodes on the skin that ventricle with each contraction; it is usually about 70 mL. connect via wires and respond to weak electrical changes Superior vena cava: Along with the inferior vena cava, one of the two largest veins in the body; the superior vena cava is © Jones & Bartlettof the heart. Learning, The abbreviation LLC EKG is more commonly used © Jones & Bartlett Learning, LLC than ECG. formed by the joining of the brachiocephalic veins. NOT FOR SALEEndocardium: OR DISTRIBUTION The inner layer of the heart wall. NOTSystemic FOR SALE circuit: ORThe arteriesDISTRIBUTION and arterioles, which send Epicardium: The outer layer of the heart wall. oxygenated blood and nutrients to the body cells while Functional syncytium: A mass of merging cells that functions removing wastes. as a unit. Systole: The contraction of a heart structure. Hepatic portal system: The veins that drain the abdominal Systolic pressure: The maximum pressuring during ventricular viscera, originating in© the Jones stomach, & intestines, Bartlett pancreas, Learning, and LLCcontraction. © Jones & Bartlett Learning, LLC spleen, to carry bloodNOT through FOR a hepatic SALE portal OR vein DISTRIBUTIONto the Thyrocervical arteries: Those NOTthat branch FOR off SALEto the thyroid OR DISTRIBUTION liver. and parathyroid glands, larynx, trachea, esophagus, pharynx, Inferior vena cava: Along with the superior vena cava, one of and muscles of the neck, shoulder, and back. the two largest veins in the body; it is formed by the joining Tricuspid valve: Lying between the right atrium and ventricle, of the common iliac veins. this valve allows blood to move from the right atrium into the Mitral© Jonesvalve: The & bicuspid Bartlett valve; Learning, it lies between LLC the left atrium right ventricle© Jones while preventing & Bartlett backflow. Learning, LLC Vasoconstriction: The contraction of blood vessels, which andNOT left ventricle,FOR SALE preventing OR blood DISTRIBUTION from flowing back into NOT FOR SALE OR DISTRIBUTION the left atrium from the ventricle. reduces their diameter. Myocardium: The thick middle layer of the heart wall that is Vasodilation: The relaxation of blood vessels, which increases mostly made of cardiac tissue. their diameter. Pacemaker: The term used to refer to the sinoatrial node (SA Veins: Blood vessels that carry blood back to the atria; they are less elastic than arteries. © Jones & Bartlettnode). Learning, LLC © Jones & Bartlett Learning, LLC Papillary muscles: Those muscles that contract as the Ventricles: The lower chambers of the heart; they receive NOT FOR SALEheart’s OR ventricles DISTRIBUTION contract, pulling on the chordae tendineaeNOT FORblood fromSALE the atria,OR whichDISTRIBUTION they pump out into the arteries. to prevent the cusps from swinging back into the atrium. Venules: Microscopic vessels that link capillaries to veins. Pericardium: A membranous structure that encloses the Vertebral arteries: One of the main divisions of the heart and proximal ends of the large blood vessels and that subclavian and common carotid arteries; the vertebral consists of double layers. arteries run upward through the cervical vertebrae into the Peripheral resistance:© A Jones force produced & Bartlett by friction Learning, between LLCskull and supply blood to the vertebrae,©