• The adult heart weighs about 280
grams (10 oz.)
• At rest, the heart pumps out about
80 millimeters (2.6 oz) of blood with
each beat.
•
2.02 Understand the functions and
disorders of the circulatory system
2
The heart beats, on average, 70
times each minute at rest.
This means all the blood is
circulated (goes round the body
once) in about one minute.
During strenuous exercise the
heart can pump six to eight
times the amount of blood that
it pumps at rest.
Functions
• Pump
• Blood transport system around body
• Carries O2 and nutrients to cells, carries
away waste products
• Lymph system – returns excess tissue
fluid to general circulation
Functions of the heart
It’s a PUMP
What do pumps do?
How does this relate to heart
function?
2.02 Understand the functions and
disorders of the circulatory system
6
Hear the beat!
2.02 Understand the functions and
disorders of the circulatory system
7
• LUBB SOUND – heard first and made
when the tricuspid & bicuspid valves close
• This is the S1 sound – heard loudest at
apex of heart
• DUPP SOUND- heard 2nd – shorter & high
pitched – caused by the semi lunar valves
in aorta and pulmonary artery closing
2.02 Understand the functions and
disorders of the circulatory system
8
Structure – Circulatory system
involves:
•
•
•
•
•
Heart
Arteries
Veins
Capillaries
Blood and lymph are part of circulatory
system
Major Blood Circuits
• General (Systemic) circulation
-to all the body (organs & systems)
• Cardiopulmonary circulation - to the lungs
& back to the heart
The Heart
•
•
•
•
•
Muscular organ
Size of a closed fist
Weighs 12-13 oz
Location –thoracic cavity
APEX – conical tip, lies on diaphragm,
points left
• Stethoscope – instrument used to hear the
heartbeat
Structure
• Hollow, muscular, double pump that
circulates blood
• At rest = 2 oz blood with each beat, 5
qts./min., 75 gallons per hour
• Ave = 72 beats per minute
• 100,000 beats per day
Layers of the heart
• PERICARDIUM – double layer of fibrous
tissue that surrounds the heart
• MYOCARDIUM – cardiac muscle tissue
• ENDOCARDIUM – smooth inner lining of
heart
• SEPTUM – partition (wall) that separates
right half from left half
• Superior vena cava and inferior vena cava
– bring deoxygenated blood to right atrium
Pulmonary artery – takes blood away from
right ventricle to the lungs for O2
Pulmonary veins – bring oxygenated blood
from lungs to left atrium
Aorta – takes blood away from left ventricle
to rest of the body
Chambers and Valves
• SEPTUM divides into R and L halves
• Upper chambers – RIGHT ATRIUM and
LEFT ATRIUM
• Lower chambers – RIGHT VENTRICLE
and LEFT VENTRICLE
Four heart valves permit flow of blood in one
direction:
1. TRICUSPID VALVE – between right atrium
and right ventricle
2. BICUSPID (MITRAL) VALVE – between left
atrium and left ventricle
3. & 4. Semilunar valves are located where blood
leaves the heart - PULMONARY SEMILUNAR
VALVE and AORTIC SEMILUNAR VALVE
PHYSIOLOGY OF THE HEART
• The heart is a double pump. When the
heart beats…
• Right Heart
• Deoxygenated blood flows into heart from
vena cava  right atrium  tricuspid valve
 right ventricle  pulmonary semilunar
valve  pulmonary artery  lungs (for
oxygen)
• Left Heart
• Oxygenated blood flows from lungs via
pulmonary veins  left atrium  mitral
valve  left ventricle  aortic semilunar
valve  aorta  general circulation (to
deliver oxygen)
http://www.smm.org/studio3d/julie/hearthome.htm
• Blood Supply to the Heart – from
CORONARY ARTERIES
• Heart Sounds = lubb dupp
http://sln.fi.edu/biosci/monitor/heartbeat.html
It’s electric!
Discuss the function of
the heart’s conduction
system.
2.02 Understand the functions and
disorders of the circulatory system
26
Control of Heart Contractions
•
•
•
•
SA (sinoatrial) NODE = PACEMAKER
Located in right atrium
SA node sends out electrical impulse
Impulse spreads over atria, making them
contract
• Travels to AV Node
• AV (atrioventricular) NODE
• Conducting cell group between atria and
ventricle
• Carries impulse to bundle of His
• BUNDLE OF HIS
• Conducting fibers in septum
• Divides into R and L branches to network
of branches in ventricles (Purkinje fibers)
• PURKINJE FIBERS
• Impulse shoots along Purkinje fibers
causing ventricles to contract
ELECTROCARDIOGRAM (EKG or
ECG)
• Device used to record the electrical activity of
the heart.
• SYSTOLE = contraction phase
• DIASTOLE = relaxation phase
• Baseline of EKG is flat line
• P = atrial contraction
• QRS = ventricular
contract
• T = ventricular
relaxation
• HOLTER MONITOR – 24 hour EKG
• CARDIOPULMONARY CIRCULATION –
heart and lungs
SYSTEMIC CIRCULATION –
from the heart to the
tissues and cells, then
back to the heart
As the Blood Flows
• Deoxygenated Blood from Body Tissue

• Superior/inferior vena cava 
• Right Atrium 
• Tricuspid Valve opens 
• Right Ventricle 
• Pulmonic Valve 
• Pulmonary Artery 
• Both Lungs 
• CO2 - O2 exchange Alveolar via
Pulmonary Veins 
• Left Atrium 
• Mitral Valve Opens 
• Left Ventricle 
• Aortic Valve Opens 
• Aorta - Transporting Oxygenated Blood
to Body Cells
http://www.dgs.k12.il.us/heart.htm
• ARTERIOLES – small arteries
• VENULES – small veins
Systemic Circulation
• AORTA – largest artery
in the body
• First branch is coronary
artery
• Aortic arch
• Many arteries branch
off the descending aorta
Blood Vessels
ARTERIES
• Carry oxygenated blood away from the
heart to the capillaries
• Elastic, muscular and thick-walled
• Transport blood under
very high pressure
CAPILLARIES
Smallest blood vessels, can only be seen
with a microscope
• Connect arterioles with venules
• Walls are one-cell thick and extremely thin
– allow for selective permeability of
nutrients, oxygen, CO2 and metabolic
wastes
VEINS
• Carry deoxygenated blood away from
capillaries to the heart
• Veins contain a muscular layer, but less
elastic and muscular than arteries
• Thin walled veins collapse easily when not
filled with blood
• VALVES – permit flow
of blood only in direction
of the heart
• JUGULAR vein – located
in the neck
Blood Pressure
• Surge of blood when heart pumps creates
pressure against the walls of the arteries
• SYSTOLIC PRESSURE – measured
during the contraction phase
• DIASTOLIC PRESSURE – measured
when the ventricles are relaxed
• Average systolic = 120
• Average diastolic = 80
PULSE
– alternating
expansion and contraction
of an artery as blood flows through it.
Pulse sites:
• BRACHIAL
• CAROTID
• RADIAL
• POPLITEAL
• PEDAL
• FEMORAL
• TEMPORAL
Diseases of the Heart
• ARRHYTHMIA (or dysrrhythmia) – any
change from normal heart rate or rhythm
• BRADYCARDIA – slow heart rate (<60
bpm)
• TACHYCARDIA – rapid heart rate (>100
bpm)
Circulatory disorders
• Murmurs
2.02 Understand the functions and
disorders of the circulatory system
49
• MURMURS – indicates defect in heart
valve – valves fail to close properly,
causing gurgling or hissing sound.
Circulatory disorders
• Coronary artery disease
2.02 Understand the functions and
disorders of the circulatory system
51
MITRAL VALVE PROLAPSE
– mitral valve closes imperfectly – symptoms
occur in response to stress, including
fatigue, PALPITATIONS (heart feels like it
is racing) headache, chest pain, and
anxiety.
Infectious Diseases of the Heart
• Cause = virus or bacteria
• Treatment = antibiotics
•PERICARDITIS – inflammation of outer
membrane covering the heart – symptoms are
chest pain, cough, dyspnea (difficulty breathing),
tachycardia, and fever.
• MYOCARDITIS – inflammation of heart
muscle – symptoms the same as
pericarditis
• ENDOCARDITIS – inflammation of the
membrane that lines the heart and covers
the valves, causes rough spots in the
endocardium which may lead to the
development of a thrombus
Coronary Artery Disease
• ANGINA PECTORIS – chest pain, caused
by lack of oxygen to heart muscle, treat
with nitroglycerin to dilate coronary
arteries
Circulatory disorders
• Myocardial infarction
2.02 Understand the functions and
disorders of the circulatory system
58
MYOCARDIAL INFARCTION
• MI or heart attack
• Lack of blood supply to myocardium
causes damage
• Due to blockage of coronary artery or
blood clot atherosclerosis – plaque buildup on arterial walls, or arteriosclerosis –
loss of elasticity and thickening of wall.
• Amount of damage depends on size of area
deprived of oxygen
• Symptoms – severe chest pain radiating to left
shoulder, arm, neck and jaw. Also nausea,
diaphoresis, dyspnea.
• Immediate medical care is critical
• Rx – bedrest, oxygen, medication
• Morphine for pain, tPA to dissolve clot
• Anticoagulant therapy to prevent further clots
from forming
• Angioplasty and by-pass surgery may be
necessary
Circulatory disorders
• Heart failure
2.02 Understand the functions and
disorders of the circulatory system
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CONGESTIVE HEART FAILURE
• Ventricles unable to contract effectively
and blood pools in the heart
• Edema in lower extremities
• Blood backs up into lungs
• Rx – drugs to strengthen
heart beat (digoxin) and
Diuretics to reduce fluid
Circulatory disorders
• Pulmonary edema
2.02 Understand the functions and
disorders of the circulatory system
64
• Heart failure – left side of heart does not
pump effectively
• Rt. Side pumps effectively, but left cannot
keep up with blood being delivered.
• Blood backs up into lungs, increasing
pressure in those vessels
• Once pressure reaches certain point, fluid
leaks out of vessels into lung tissue and
even air spaces
Heart Surgery
• ANGIOPLASTY – procedure to help open
clogged vessels – may also be called
“balloon surgery.”
CORONARY BY-PASS
• usually, a healthy vein from the leg
removed and attached before and after the
coronary obstruction, creating an alternate
route for blood supply to the myocardium.
HEART TRANSPLANT
• Why? Irreparably damaged myocardium, valves
or blood vessels, or baby/child with congenital
heart defect
• Problem? Histocompatibility
• Rx? Immunosuppressants
• Artificial hearts? First used in 1982. What is the
current status?
http://www.smm.org/studio3d/julie/hearthome.htm
(watch surgery)
PACEMAKERS
• Demand pacemaker – fires only when
heart rate drops below programmed
minimum
• http://www.smm.org/studio3d/julie/heartho
me.htm
watch Heart Mate
STENT
• Tiny, expandable stainless steel tube that
holds coronary artery open following
angioplasty
http://www.cardiologyassociates.net/patientinfo_edu.asp?fs=2
(click to view animation – watch stent)
• CPR – cardiopulmonary resuscitation,
used in the presence of cardiac arrest
• DEFIBRILLATION – electrical shock to
bring the heart back to a normal rhythm.
• AED – automated external defibrillator
• HEART BLOCK – disturbance in electrical
conductivity of the heart beat
Circulatory disorders
• Aneurysm
2.02 Understand the functions and
disorders of the circulatory system
81
Disorders of the Blood Vessels
• ANEURYSM – ballooning of an artery,
thinning and weakening
Circulatory disorders
• Peripheral vascular disease
2.02 Understand the functions and
disorders of the circulatory system
83
• ATHEROSCLEROSIS – fatty deposits
form on walls of arteries
Carotid endarterectomy
Circulatory disorders
• Arteriosclerosis
2.02 Understand the functions and
disorders of the circulatory system
89
• ARTERIOSCLEROSIS – arterial walls
thicken, lose elasticity.
• Causes narrowing of blood vessel opening
• PHLEBITIS – inflammation of lining of
vein, accompanied by clotting of blood –
symptoms are edema, pain and redness
• EMBOLISM – traveling blood clot
• VARICOSE VEINS – swollen, distended
veins – heredity or due to posture,
prolonged periods of standing, physical
exertion, age and pregnancy
Circulatory disorders
• Varicose veins
• Prevention
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–
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–
Wear sunscreen
Elevate legs when resting
Wear elastic support stockings
Eating fiber diets
Exercise
Understand the functions and
Weight control2.02
disorders of the circulatory system
94
• HEMORRHOIDS - varicose rectal veins
• HYPOTENSION – low blood pressure,
systolic <100
HYPERTENSION
• High blood pressure
• “silent killer” – usually no symptoms
• Condition leads to strokes, heart attacks, and
kidney failure
• 140/90 or higher
• Higher in African-Americans and postmenopausal women
• Risk factors = smoking, overweight, stress, high
fat diets, family history
• Treatment = relaxation, low fat diet, exercise,
weight loss, medication
Circulatory disorders
• Transient ischemic attack
2.02 Understand the functions and
disorders of the circulatory system
99
Diagnostic Tests
• CARDIAC CATHETERIZATION – catheter
fed into heart, dye injected, x-rays taken
as dye moves through coronary arteries
http://www.cardiologyassociates.net/patientinfo_edu.asp?fs=2
Click watch animation – cardiac catheterization
http://www.cardiologyassociates.net/patientinfo_edu.asp?fs=2
(CLICK TO VIEW ANIMATION – ANGIOPLASTY)
• ANGIOGRAM – x-ray of a blood vessel
using dye
• ELECTROCARDIOGRAM – electrical tracing
of the heart