The Cardiovascular System
http://thevirtualheart.org/
 A closed system of the heart and blood vessels
 The heart _________________ blood
 Blood vessels allow blood to __________________ to all parts of the body
 The function of the cardiovascular system is to deliver ________________ and
_____________and to remove ___________________ and other waste products
11.1.1 Describe the location of the heart in the body and identify its
major anatomical areas on an appropriate model or diagram.
The Heart
 Location
 Thorax between the _______________
 Pointed apex directed toward __________________
 About the size of your fist
 Less than _________________
 Coverings
 Pericardium – a _____________________ serous membrane
 Visceral pericardium
 Next to heart
 Parietal pericardium
 ________________ layer
 ________________ fluid fills the space
between the layers of
pericardium
 Heart Wall
 Three layers
 __________________
 Outside layer
 This layer is the parietal
pericardium
 Connective tissue layer
 ____________________
 Middle layer
 Mostly cardiac muscle
 ___________________
 Inner layer
 Endothelium
 Chambers
 Right and left side act as separate pumps
 Four chambers
 ______________
 ________________ chambers
 Right atrium
 Left atrium
 _____________
 Discharging chambers
 Right ventricle
 Left ventricle
11.1.3 Explain the operation of the heart valves.
 Valves
 Allow blood to flow in only _________________ direction
 Four valves
 Atrioventricular valves – between __________ and ventricles
 Bicuspid valve (left)
 _________________ valve (right)
 Semilunar valves between ventricle and ________________
 __________________________ semilunar valve
 Aortic semilunar valve
 Valves ________________ as blood is pumped through
 Held in place by chordae ____________________(“heart strings”)
 Close to prevent _________________
 Valve Pathology
 Incompetent valve = backflow and _______________
 Stenosis = stiff= heart workload increased
 May be replaced by ____________________________
 Lup Dub Heart Sound
 Associated Great Vessels
 Aorta
 Leaves left ventricle
 ____________________ arteries
 Leave right ventricle
 __________________
 Enters right atrium
 Pulmonary veins (four)
 Enter left ___________________
11.1.4 Name the functional blood supply of
the heart.
 Coronary Circulation
 Blood in the heart chambers does not
nourish the ____________________
 The heart has its own nourishing
_______________________ system
 Coronary arteries
 Cardiac veins
 Blood empties into the
______________________________________ via
the coronary sinus
 Cardiac Pathology
 Rapid heart beat
 = Inadequate blood
 = Angina Pectoris
Physiology of the Heart
 Body has 6 quarts of blood
 1000 times a day
 6000 quarts a day
11.2.1
Name the elements of the intrinsic conduction system of the heart and
describe the pathway of impulses through this system
Conduction System
 Cardiac muscle contract _______________ and independently, even if nerves are severed.
 Different areas of the heart have different rhythms.
 Atrial – about 60/min
 Ventricular – about __________
 A controlling system is needed
 Autonomic nervous system
 _________________________ system (nodal system)
 Intrinsic conduction system (nodal system)
 Composed of a special tissue found now where else
 Cross between ______________ and ______________
 Causes heart to depolarize and a contraction rate (≈75/min)
 Special tissue sets the pace
 _________________ (SA) node (right atrium)
 Pacemaker
 Atrioventricular(AV) node (junction of r&l atria and
ventricles)
 Atrioventricular _____________ (Bundle of His)
 Bundle branches (right and left)
 _________________ fibers
1) Depolarization starts in the SA node
2) Impulse spreads through the _____________ to the AV node, causing the atria to ____________.
3) At AV node, impulse is ______________.
4) Gives atria time to finish contracting.
5) Then impulse passes rapidly through the AV bundle, bundle branches and Purkinje fibers.
6) This “____________” the heart
7) Blood ejects blood into arteries.
 Atria and ventricles are separated by “_________________” connective tissue
 Depolarization waves can reach the ventricles only through the AV node.
11.2.4 Explain what information can be gained from an electrocardiogram.
Electrocardiograms (EKG/ECG)
 Three formations
 P wave: impulse across atria
 QRS complex: spread of impulse down septum,
around ventricles in Purkinje fibers
 T wave: end of electrical activity in ventricles
 Electrocardiogram(ECG/EKG)
 Atria contract ___________________
 Atria relax, then ventricles contract
 Systole = ______________
 Diastole = relaxation
 The terms systole and diastole refer to the contraction and relaxation of the ______________.
 _____________________ – refers to the events of one complete heartbeat.
 Both the atria and ventricles must contract and relax.
 This happens in about _________ second.
11.2.3 Define heart sounds and murmur.
Sounds of the heart
 “lub” - “dub” – pause -“lub” - “dub” – pause
 lub – closing of the _________ valves
 Louder and longer
 dub – closing of the _____________ valves
 Softer and shorter
 Murmurs – abnormal or unusual heart sounds
 Normally blood flow is __________
 Caused by incompetent valves
Pathology of the Heart
 Damage to AV node = release of ventricles from control = slower heart beat
 Slower heart beat can lead to _______________
 Fibrillation is the rapid uncoordinated _________________ of the heart muscle.
 Fibrillation = lack of blood flow to the heart
 Tachycardia = more than 100 beats/min
 Bradychardia = less than 60 beats/min
11.2.5 Describe the effect of an increased and decreased heart rate including CHF.
Cardiac output
 CO = HR x SV
 ___________ ml/min = 75 beats/min x 70 mls/beat
 Norm = 5000 ml/min
 Entire blood supply passes through body once per ___________________.
 CO varies with demands of the body.
Regulation of Heart
 Stroke volume usually remains relatively ___________________
 Starling’s law of the heart – the more that the cardiac muscle is stretched, the stronger the contraction
 Changing heart rate is the most common way to change cardiac output
 Increased heart rate
 Sympathetic nervous system
 ___________
 Low blood pressure
 Hormones
 ______________
 Thyroxine
 Exercise
 Decreased blood volume
 Decreased heart rate
 Parasympathetic nervous system
 __________blood pressure or blood volume
 Dereased venous return
 In Congestive Heart Failure the heart is _________________and pumps weakly. Digitalis works to
provide a slow, steady, but stronger beat.
 Congestive Heart Failure (CHF)
 Decline in pumping ________________ of heart
 Inadequate circulation
 Is a progressive high blood pressure and history of multiple Myocardial Infarctions
 Caused by atherosclerosis ( ________________ of the coronary vessels with fatty build up.
 Left side fails = pulmonary congestion and suffocation
 Right side fails = _______________ congestion and edema
Physiology of Circulation
11.3.2 Define blood pressure and pulse and name
several pulse points.
Vital Signs
 __________________ pulse
 Blood pressure
 _____________________ Rate
 Body Temperature
 All indicate the efficiency of the system
Pulse
 _____________________ wave of blood
 Alternating expansion and recoil of an artery that occurs
with each beat of the left ___________________.
 Around 73 beats per minute
 Monitored at “_______________________________” where pulse is
easily palpated
 These pressure points can be used to help stop
________________________.
11.3.3 List factors affecting and/or determining blood pressure.
Blood Pressure
 The pressure the _________________ exerts against the inner walls of the blood vessels .
 Keeps blood circulating ____________________________ even between heartbeats.
 Highest in large arteries/lowest in the venae cavae.
 If vein is cut blood flow is ________________________
 If artery is cut blood flow would squirt .
 Measurements by health professionals are made on the pressure in large arteries
 ____________________ – pressure at the peak of ventricular contraction
 ____________________ – pressure when ventricles relax
 Pressure in blood vessels _____________________ as the distance away from the heart increases
 Measured in mm Hg
Measuring Arterial Blood Pressure
 Ausultatory Method
BP: Effects of Factors
 BP is directly related to cardiac output and ___________________ ___________________ .
 Peripheral resistance – the amount of __________________ encountered by the blood as it flows through
the blood vessels.
 Most important factor is the _____________________ or narrowing of blood vessels.
 Blood volume and viscosity raises periheral resistance.
 Others: age, weight, time of day , exercise, body position, emotional state, drugs.
11.3.3 List factors affecting and/or
determining blood pressure.
Factors on BP
1)Neural factors
 Autonomic nervous system
adjustments (sympathetic
division)
 Causes ________________________ –
narrowing of the blood vessels,
which increases the blood
pressure.
 Examples: standing up, hemorrhaging, exercise or frightened
 Never causes vasoconstriction of _____________ or ____________ vessels.
2) Renal factors: the kidneys
 Regulation by altering blood volume
 BP _________________ = water leaves body through urine.
 _____________ – hormonal control, a vasoconstrictor chemical
3) Temperature
 Heat has a vaso_______________ effect
 Warm compresses for inflamed areas
 Cold has a vaso_______________ effect
 Cold packs for swelling bruises
4) Chemicals
 Various substances can cause increases or decrease
 Epinephrine, Nicotine - _________________
 Alcohol, Histamine - _________________
5) Diet - Opinions always changing
 Overall excepted – salt, saturated fats, cholesterol prevent _____________________.
11.3.4 Define hypertension and atherosclerosis and describe possible health consequences
of these conditions.
Variations in Blood Pressure
 Human normal range is variable
 Normal
 ________________ mm Hg systolic
 ________________ mm Hg diastolic
 Hypotension – overall viewed as a good thing
 Low systolic (below 110 mm HG)
 Often associated with illness or poor _________________
 Hypertension- High systolic (above 140 mm HG)
 Can be dangerous if it is chronic
 Linked to diet, _______________ , heredity, race, stress