Transcript cardiovascular system

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• 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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Two-sided, double pump
Weighs less than a pound
Slightly bigger than a fist
Located between the lungs in the thoracic cavity
Positioned partially to the left of the sternum
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• Four chambers of the heart
◦ Atria
 Top two chambers
 Blood enters the heart through the atria
◦ Ventricles
 Lower two chambers
 Blood leaves the heart through the ventricles
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Septum
◦ Divides the right and left sides of the heart
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Pulmonary circulation
◦ Right side of heart pumps deoxygenated blood to the lungs
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Systemic circulation
◦ Left side of the heart pumps oxygenated blood to rest of
the body
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Blood returns to the right side of the heart from the
body to complete the cycle
Hepatic circulation
◦ Path of the blood from the intestines, gallbladder,
pancreas, stomach, and spleen through the liver
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• Four valves of the heart
◦ Prevent blood from flowing back into heart
◦ Atrioventricular
 Separate the atria and ventricles
◦ Semilunar valves
 Separate the ventricles from the pulmonary artery and aorta
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Endocardium
◦ Smooth layer of cells lining the inside of the heart and
forming the valves
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Myocardium
◦ The thickest layer, consisting of muscle tissue
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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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Activity of the heart muscle is controlled by the
nervous system
◦ Also affected by action of hormones and fluid balance
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Heart is the only muscle that can stimulate its own
contractions
◦ Sinoatrial cells (SA node) in right atrium
 Start the heart
◦ Atrioventricular node (AV node)
 Sends impulse into lower portions of the heart
◦ AV bundle or bundle of HIS
 Stimulate the Purkinje fibers
◦ Purkinje fibers
 Cause the ventricles to contract
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Arteries
◦ Carry blood away from the heart
 Blood is oxygenated
◦ Have a muscular layer of tissue that helps pump blood out
of the body
◦ Aorta is the largest artery in the body, which branches into
smaller arteries
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Arterioles
◦ Smaller vessels
◦ Blood moves from arterioles to capillaries
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Capillaries
◦ Microscopic vessels that carry blood between the arterial
and venous vessels
◦ Gases, nutrients, and waste exchanged
 Blood gives up oxygen
◦ Blood flows from capillaries into venules
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Veins
◦ Venues branch together to form veins
◦ Carry blood back to the heart by gravity
 Blood is deoxygenated except for pulmonary vein
◦ Contain values that prevent blood from flowing back
◦ Have a much thinner muscular layer
◦ Superior vena cava and inferior vena cava
 Largest veins
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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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Pulse
◦ Surge of blood against the walls of the arteries
◦ Eight pulse points on the body
◦ Normal pulse rate for adults is 60 to 90 beats per minute
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Blood pressure
◦ Force of blood against the walls of the arteries
◦ Systolic pressure
 Ventricles of the heart contract
◦ Diastolic pressure
 Ventricles relax
◦ Normal blood pressure
 120/80
◦ Blood pressure varies greatly among people
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Heart sounds
◦ Lub-dub sound of the heart
◦ Heard through a stethoscope
◦ Murmurs
 Abnormal or extra sound
 Classified by timing, intensity, location, pitch, and quality
of the sound
 May be benign or indicate a disorder
◦ Thrill
 Vibration felt by touch over an artery
 Caused by an abnormal flow of blood
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Electrocardiogram
◦ Measures graphically the pattern of electrical activity in
heart contractions
 Normal and abnormal heart activities have characteristic wave
patterns
◦ Echocardiography
 Uses ultrasonic waves to show the structures and motions of
the heart
 Transducer plots the sound echoes to produce a graphic
picture
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Cardiac catheterization
◦ Used to measure the pressure in the chambers of the heart,
to take blood samples, and to view obstructions in the
vessels
 A tube is inserted through the blood vessels into the heart
 Dye is then released and traced using x-ray
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Aneurysm
◦ An area of a blood vessel that bulges because of a weakness
in the wall
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Atherosclerosis
◦ A narrowing of blood vessels caused by deposits of fatty
material containing calcium and cholesterol
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Cardiac arrhythmia
◦ A disturbance of the heart’s rhythm caused by a defect in
the heart’s pacemaker cells or by damage to heart tissue
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Cardiovascular disease
◦ A general term for the combined effects of
arteriosclerosis, atherosclerosis, and related conditions
called coronary artery disease
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Congenital heart disease
◦ A group of disorders that affect about 25,000 newborns
each year in the united states
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Congestive heart failure
◦ The inability of the heart to pump blood adequately to
meet the body’s needs
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Hypertension
◦ High blood pressure
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Myocardial infarction
◦ Known as a heart attack
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Phlebitis
◦ An inflammation of a vein, often with formation of a
clot
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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
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Varicose veins
◦ A condition in which veins become enlarged and
ineffective
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Heart replacement and transplants
◦ 1967 - First heart replacement
 Approximately 2,300 heart transplants each year in the United
States
 First artificial heart, Jarvik-7
 Connected to an external power source and pump
◦ 2001 AbioCor self-contained artificial heart
 Designed to test how long it could extend life for people with
end-stage heart failure
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◦ 2005 FDA approved use of Syn Cardia CardioWest
Temporary Total Artificial Heart
 Used in patients with irreversible failure of the ventricles
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More than 3,000 people are on a waiting list for a
heart transplant
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Cholesterol controversy
◦ LDL vs. HDL
 Harvard research study
 Type of fat in the diet, not the amount, changes the cholesterol level
 Limit intake of saturated fats and eliminate trans fats
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