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1、Ch 11 Cardiovascular system1. Describe the structures of the cardiac wall and pericardial coverings.Cardiac Wallpericardial coverings(1) Epicardium* Outer connective tissue layer* Is the visceral pericardium(2) Myocardium* Middle layer* Mostly cardiac muscle(3) Endocardium* Inner epithelial tissue l
2、ayer* Is called endothelium(1) Fibrous pericardium is loose and superficial(2) Serous membrane is deep to the fibrous pericardium and composed of two layers* Visceral pericardium (also known as the epicardium) Attached to the heart* Parietal pericardium Outer layer that lines the inner surface of th
3、e fibrous pericardium(3) Serous fluid fills the space between the two layers of pericardium2. What do heart valves separate and what are their functions?FunctionsAllow blood to flow in only one direction to prevent backflowSeparate1. Atrioventricular (AV) valves: between atria and ventricles(1) Bicu
4、spid (mitral) valve (left side of the heart)(2) Tricuspid valve (right side of the heart)2. Semilunar (SL) valves: between ventricles and arteries(1) Pulmonary semilunar valve(2) Aortic semilunar valve3. Describe the systemic, pulmonary, and coronary circulations.Systemic circulationBlood flows from
5、 the left side of the heart through the body tissues and back to the right side of the heartPulmonary circulationBlood flows from the right side of the heart to the lungs and back to the left side of the heartcoronary circulation(1) Coronary arteries: branch from the aorta to supply the heart muscle
6、 with oxygenated blood(2) Cardiac veins: drain the myocardium of blood(3) Coronary sinus: a large vein on the posterior of the heart that receives blood from cardiac veins, and empties it into the right atrium4. Describe the great vessels that are associated with the heart.More vessels, such as coro
7、nary arteries, cardiac veins, and coronary sinus.Arteries(1) Aorta : Leaves the left ventricle(2) Pulmonary trunk (divides into arteries) : Leaves the right ventricleVeins(1) Superior and inferior venae cavae : Enter the right atrium(2) Pulmonary veins : Enter the left atrium5. Describe the conducti
8、on system of the heart. SA node AV node - AV bundle (bundle of His) -Bundle branches - Purkinje fibers6. Where is the normal cardiac pacemaker? SA node 7. What happens during the cardiac cycle?8. What is the mechanism of the normal heart sounds?(1) Av valve closure causes the first heart sound, desc
9、ribed as “lubb” during the isovolumetric contraction phase.(2) SL valve closure causes the second heart sound, described as “dupp” during the isovolumetric relaxation. Mechanism means how heart sounds are generated, and during which particular phases as seen in the above diagram.9. How is the heart
10、rate regulated?Increased heart rate 1. Sympathetic nervous system (1) stimulationCrisis(2) Low blood pressure2. Hormones(1) Epinephrine(2) Thyroxine3. Exercise4. Decreased blood volumeDecreased heart rate 1. Parasympathetic nervous system stimulation2. High blood pressure or blood volume3. Decreased
11、 venous return10. How is the cardiac output regulated?(1) Cardiac output(CO): Amount of blood pumped by each ventricle of the heart in on minute.(2) Stroke volume(SV):Volume of blood pumped by each ventricle in one contraction.(3) Heart rate(HR): Number of beats per minute. CO = HR SV Changing heart
12、 rate is the most common way to change the cardiac output.How stroke volume (SV) affects cardiac output?11. Why does the increased heart rate reduce the stroke volume?=increased heart rate may decrease the stroke volume because of lack of enough time for ventricular filling12. Compare the structures
13、 of the different types of blood vessels.What vessels are pressure, volume, or exchange vessels?Arteries Distribution and resistanceArteriolesResistance (Pressure & flow regulation)Capillaries only one cell layer (tunica intima) to allow for exchanges between blood and tissueExchangeVenulesExchange,
14、collection, and capacitanceVeins Capacitance function (blood volume)13. What structures help venous return of blood to the heart?Skeletal muscle and venous valves14. Describe the arterial blood supply to the brain.(1) Internal carotid arteries divide into anterior and middle cerebral arteries, which
15、 supply the anterior and middle parts of the cerebrum(2) Vertebral arteries join, once within the skull, to form the basilar artery, which serves the brain stem and cerebellum(3) Posterior cerebral arteries form from the division of the basilar artery, and supply the posterior part of the cerebrum15. Describe the hepatic portal circulation.(1) Veins of hepatic portal circulation drain* Digestive organs* Spleen* Pancreas (2) Hepatic portal vein carries this blood to the liver (3) Liver helps maintain pr
