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Cardiovascular System. Chapter 11. Anatomy of the Heart. Location and Size The size of the heart is slightly larger than a person’s fist Apex – the pointed end of the heart Base – the broad portion of the heart. Base. Apex. Anatomy of the Heart (cont.). Coverings
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Cardiovascular System Chapter 11
Anatomy of the Heart • Location and Size • The size of the heart is slightly larger than a person’s fist • Apex – the pointed end of the heart • Base – the broad portion of the heart Base Apex
Anatomy of the Heart (cont.) • Coverings • Pericardium – a double sac of serous membranes that surrounds the heart • Visceral (epicardium) – tightly hugs the external surface of the heart • Parietal – the outer layer that anchors the heart to the diaphragm and sternum • Serous fluid located inside the pericardium used to prevent friction
Anatomy of the Heart (cont.) • Walls • Epicardium – the outermost layer of the heart • Myocardium – the middle layer (a muscle) that actually contracts • Endocardium – the innermost layer that lines the heart’s chambers
Anatomy of the Heart (cont.) • Flow of blood through vessels • Artery • Carries blood away from the heart • Thickest blood vessel • Arteriole - small artery • Capillary • smallest blood vessel • A couple of cell layers thick • Venule – small vein • Vein • Carries blood towards the heart
Color of Blood and Blood Vessels • Common misconception: blood is blue in the body • Truth: blood is always a shade of red • Oxygenated blood is a bright-red color • Deoxygenated blood is a dark-red, maroon color • In books and diagrams, oxygenated blood is depicted red & deoxygenated blood is blue • Blood vessels are colorless without blood https://www.msu.edu/~kalinkat/professionalpages/TechMatrixMaterials/documentarybloodmisconceptions.htm
Anatomy of the Heart (cont.) • Chambers and Vessels • http://science.nationalgeographic.com/science/health-and-human-body/human-body/heart-article.html • http://www.texasheartinstitute.org/HIC/anatomy/Anatomy.cfm
Flow of Blood Through Heart • 1. Superior vena cava – carries deoxygenated blood from the head, neck, and arms into the right atrium
Flow of Blood Through Heart • 1. Inferior vena cava – carries deoxygenated blood from the legs and other lower parts of the body into the right atrium
Flow of Blood Through Heart • 2. Right atrium – Hollow, receiving chamber that collects deoxygenated blood from the vena cavae before sending it to the right ventricle
Flow of Blood Through Heart • 3. Tricuspid valve - valve with three cusps; situated between the right atrium and the right ventricle
Flow of Blood Through Heart • 4. Right ventricle – muscular, hollow chamber that collects deoxygenated blood from the right atrium before sending it to the pulmonary artery
Flow of Blood Through Heart • 5. Pulmonary semilunar valve – a valve between the right ventricle and the pulmonary artery; prevents blood from flowing from the artery back into the heart
Flow of Blood Through Heart • 6. Pulmonary artery – carries deoxygenated blood from the right ventricle to the lungs
Flow of Blood Through Heart • 7. Lungs – Location where deoxygenated blood becomes oxygenated
Flow of Blood Through Heart • 8. Pulmonary vein – carries oxygenated blood from the lungs into the left atrium
Flow of Blood Through Heart • 9. Left atrium – Hollow, receiving chamber that collects oxygenated blood from the pulmonary vein before sending it to the left ventricle
Flow of Blood Through Heart • 10. Bicuspid valve (or mitral valve) - Permits blood to flow from the left atrium into the left ventricle
Flow of Blood Through Heart • 10. Bicuspid valve (or mitral valve) • This valve is called the mitral valve because it has two flaps (cusps) and looks like a bishop's miter or headdress
Flow of Blood Through Heart • 11. Left ventricle – muscular, hollow chamber that collects oxygenated blood from the left atrium before sending it to the aorta
Flow of Blood Through Heart • 12. Aortic semilunar valve – a valve between the left ventricle and the aorta; prevents blood from flowing from the artery back into the heart
Flow of Blood Through Heart • 13. Aorta – Large artery that distributes oxygenated blood from the heart to the rest of the body
Exterior Structures • Coronary arteries – vessels that provide the heart muscle with the oxygenated blood it needs to keep tissues healthy Coronary Artery Disease
Internal Structures • Septum – a dividing wall or partition
Papillary muscles – the rounded muscular projections attached to the chordae tendineae in the ventricles of the heart Internal Structures
Chordae tendineae (or heart strings) – cord-like tendons that connect the papillary muscles to the tricuspid valve and bicuspid valve Internal Structures Chordae tendineae
Bicuspid valve Pulmonary Semilunar Valve Aortic Semilunar Valve Chordae tendineae Septum
(Bicuspid Valve) Pulmonary Semilunar Valve Aortic Semilunar Valve Left
Blood Flow Through the Heart • http://www.youtube.com/watch?v=mH0QTWzU-xI
Valves • There are two sounds heard during each heart beat. These are called Lub-Dub noises. • When atrioventricular (AV) valves close, a "lub" sound is heard. • The first sound heard in the heart • When the semilunar valves close, a "dub" sound is heard followed by a longer pauseLub-DubLub-Dub. • The second sound heard in the heart
Murmurs • If the valves do not close properly and leak, the sound will not be clear but blurred. • This sound is more of a Lub-Shhh-Dub or Lub-Dub Rumble.
Varicose Veins • A.K.A “spider veins” • Varicose veins are gnarled, enlarged veins. • Caused by valves in blood vessels not closing properly and pooling of blood causes the veins to swell
Cardiac Circulation • Pulmonary circulation • Pulmonary - lungs • Located on the right side of the heart • Deoxygenated side • Systemic circulation • Systemic - body • Located on the left side of the heart • Oxygenated side
Physiology of the Heart • Intrinsic conduction system – the system that conducts heartbeats • Sinoatrial (SA) node – The pacemaker that sends electrical signals in the right atrium • Atrioventricular (AV) node – Located between the right atrium and right ventricle • AV bundle – Found in the septum • Purkinje fibers – Found along the sides of the heart
Heart Attack and Treatments • http://science.nationalgeographic.com/science/health-and-human-body/human-body/heart-article.html
Cardiac Output • Cardiac output (CO) – Amount of blood pumped by each ventricle of the heart in one minute • Stroke volume (SV) – Volume of blood pumped by each ventricle in one contraction (each heartbeat) • About 70 mL of blood is pumped out of the left ventricle with each heartbeat • Usually remains relatively constant • Heart rate (HR) – Typically 75 beats per minute
Cardiac Output • CO = HR SV • CO = HR (75 beats/min) SV (70 mL/beat) • CO = 5250 mL/min • Changing heart rate is the most common way to change cardiac output