Transcript 11. 1 Heart Anatomy and Functions of the Cardiovascular System

Chapter 11: The Cardiovascular System
Lesson 11.1
Heart Anatomy and the
Function of the
Cardiovascular System
Anatomy and the Function of the
Cardiovascular System
Section topics (overview)
• the heart: location and size
• the four chambers of the heart
• the heart valves
• blood flow through the heart
• walls of the heart
• cardiac cycle
• cardiac output
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The Heart: Location and Size
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Thoracic cavity - beneath the sternum
Above diaphragm – sits on the top of the diaphragm
Between lungs – apex (point) tilted left (toward hip)
Size of a clenched fist
Weighs
– 10 – 12 ounces (males)
– 8 – 10 ounces (females)
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The Heart: Location and Size
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The Four Chambers of the Heart
1. right atrium
2. right ventricle
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3. left atrium
4. left ventricle
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The Heart Valves
• Atrioventricular (AV) valves (between Atria & Ventricles)
– Tricuspid (right side)
– bicuspid (mitral) (left side)
• Semilunar valves (between ventricles and arteries)
– pulmonary
– aortic
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Blood Flow through the Heart
• (1) deoxygenated blood flows from the body to the
inferior and superior vena cavae to right atrium
• (2) right atrium contracts, forcing blood through the
tricuspid valve to right ventricle
• (3) right ventricle contracts, forcing blood through
the pulmonary valve, to the pulmonary artery
• (4) blood exits to the lungs
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Blood Flow through the Heart (continued)
• (5) oxygenated blood from lungs travels through
the pulmonary veins to the left atrium
• (6) left atrium contracts, forcing blood through the
mitral valve to the left ventricle
• (7) left ventricle contracts, forcing blood through
the aortic valve
• (8) blood passes to the aorta
• (9) blood travels out to parts of the body
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Blood Flow through the Heart
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Permission granted to reproduce for educational use only.
Walls of the Heart
• epicardium
– outermost layer
– Coronary arteries located
• myocardium
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middle layer
66% of cardiac muscle
Contracts 72- 82 beats/m
Pumps through 60,000
miles of vessels
• endocardium
– inner layer
– Lines the chambers and
covers the valves
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Cardiac Cycle
• diastole
– ventricle relax, atria contract
• systole
– ventricles contract, atria relax
• mean arterial pressure
– overall pressure within cardiovascular system
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Cardiac Output
• amount of blood pumped by heart in 1 minute
measured in liters/minute
• stroke volume
– amount of blood pumped in 1 beat
• heart rate
– number of beats per minute
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