copyright 2003 by mosby, inc. all rights reserved. chapter 10 cardiovascular system
TRANSCRIPT
Copyright 2003 by Mosby, Inc. All rights reserved.
CHAPTER 10
CARDIOVASCULAR SYSTEM
Copyright 2003 by Mosby, Inc. All rights reserved.
Structure and Function
• Functions of the cardiovascular system– Transports nutrients and oxygen to the
body – Transports waste products from the
cells to the kidneys for excretion – Distributes hormones and antibodies
throughout the body – Helps control body temperature and
maintain electrolyte balance
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Heart
• Two-sided, double pump • Weighs less than a pound• Little bigger than a fist • Located between the lungs in the
thoracic cavity• Positioned partially to the left of
the sternum
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Tissue Layers of the Heart
• Endocardium– Smooth layer of cells lining the inside of the
heart and forming the valves
• Myocardium– The thickest layer, consisting of muscle
tissue
• Pericardium – Double membrane that covers the outside
of the heart, providing lubrication between the heart and surrounding structures to prevent tissue damage
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Tissues layers of the Heart
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Blood Vessels • Arteries and arterioles
– Carry blood away from the heart – The aorta is the largest artery in the body
• Veins and venuoles– Carry blood back to the heart – The superior and inferior vena cava are the largest
veins
• Capillaries – Microscopic vessels that carry blood between
the arterial and venous vessels; where the gaseous exchanges take place
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Copyright 2003 by Mosby, Inc. All rights reserved.
Figure 10-4 Blood Vessels
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The Aorta and major Arteries
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Anatomy of the Heart• Heart- (cardi/o; coron/o)• It is a two-sided double pump;
– Rt side of heart send O2 deficient blood to lungs where the blood picks up O2 and releases CO2
– O2 rich blood returns to left side of heart and left side of heart pumps blood to rest of the body
• Four Chambers:– Two upper chambers called atrium– Two lower chambers called ventricles (ventricul/o) – Septum- divides the right side of the heart from the left
side; wall or portion within heart
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Heart Valves
• Four Valves; (valvul/o; vavl/o) –cusps or flaps of valves– Tricuspid- b/w rt atrium and rt ventricle– Pulmonary- b/w rt ventricle and pulmonary
artery– Mitral- b/w left atrium and left ventricle– Aortic- prevents return of aortic blood to left
ventricle• Patent= to open
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Figure 10-2A Structures of the Heart
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Pulmonary circulation
• Superior and Inferior Vena Cava
• Right Atrium• Tricuspid Valve• Right Ventricle
• Pulmonary Valve• Pulmonary Artery• Lungs• Pulmonary Vein• Left Atrium• Mitral Valve• Left Ventricle• Aortic Valve• Aorta (aort/o)• To body
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Systemic Circulation
• O2 rich blood leaves heart thru the aorta the largest artery in the body
• Ascending aorta• Descending aorta• Arteries• Arterioles• Tissue Capillaries• Venules• Veins• Superior and Inferior Vena Cava
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Physiology of Heart
• Heartbeat (2 phases)1. Diastole= relaxation
Diastole= short period of rest as the heart fills
2.Systole= contraction phase of heart
Systole occurs and blood is pumped away from the heart
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Phases of the Heartbeat
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Physiology of heart
• Diastole-Systole Cycle– 70-80 times per minute– 5 quarts of blood per minute– 75 gallons per hour– 2000 gallons per day
“murmur”= abnormal heart sound
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Physiology of the Heart
• Conduction System– Sinoatrial Node (SA node)= pacemaker of the
heart; sensitive tissue in the rt atrium wall that begins the heart beat
• Posterior of rt atrium
• Electrical impulse
• Atria contracts and force blood into the ventricle
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Conduction of Heart
P wave= spread of excitation over atria before contractionQRS wave= spread of excitation over ventricles as contraction occursT wave= electrical recovery and relaxation of ventricles
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Assessment Techniques
• Measuring pulse and blood pressure• Listening to heart sounds• Determining cardiac output • Measuring muscle activity with
electrocardiography • Inserting a cardiac catheter • Using echocardiography
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Blood Pressure• Blood pressure= force that the blood exerts on the
arterial walls– Sphygmomanometer- a device to measure blood
pressure (sphygm/o=pulse)– First sound= systolic pressure (pressure in the artery
when the left ventricle is contracting to force the blood into the aorta); pumping blood to the body
– Second sound= diastolic blood pressure (pressure in the artery when the ventricles are relaxing and the heart is filling); when the heart relaxes
– Written as a fraction: 120/80= systolic/diastolic
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Disorders of the Cardiovascular System (continued)• Cardiovascular disease
– A general term for the combined effects of arteriosclerosis, atherosclerosis, and related conditions called coronary artery disease
• Congenital heart disease – A group of disorders that affect about 25,000
newborns each year in the united states– Tetraology of Fallot – 4 separate heart defects
• Congestive heart failure– The inability of the heart to pump blood
adequately to meet the body’s needs
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Blood vessel pathology• Embolus- floating blood clot or other material in the
vessel
• Atherosclerosis- hardening of the arteries caused by fatty or calcium deposits in the artery walls causing them to thicken
- HDL (High-Density Lipoprotein) good
- LDL (Low-Density Lipoprotein) bad
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Pathological Conditions• Ischemia- can lead to a Myocardial Infarction (MI); blood
held from an area and can be caused by thrombotic occlusion of a blood vessel
• Arrhythmia- abnormal heart rhythms• Aneurysm- An area of a blood vessel that bulges
because of a weakness in the wall• Hypertension -High blood pressure• Myocardial infarction- Known as a heart attack• Phlebitis -An inflammation of a vein, often with formation of a
clot
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Disorders of the Cardiovascular System (continued)• Rheumatic heart disease
– A condition in which the heart muscle and valves are damaged by a recurrent bacterial infection that usually begins in the throat
• Varicose veins– A condition in which veins
become enlarged and ineffective
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Rheumatic heart
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Issues and Innovations
• Heart replacement– First artificial heart, Jarvik-7– Heart transplants