CHAPTER 10
CARDIOVASCULAR
SYSTEM
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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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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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• Superior and Inferior Vena
Cava
• Right Atrium
• Tricuspid Valve
• Right Ventricle
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•
•
•
•
•
•
•
•
•
Pulmonary
circulation
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
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P wave= spread of
excitation over
atria before
contraction
QRS wave= spread
of excitation over
ventricles as
contraction occurs
T wave= electrical
recovery and
relaxation of
ventricles
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
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