Download Circulatory System

Circulatory System
1H08.01
Explain the structure of the heart.
A. Size, shape and location
1. Size of closed fist
2. In thoracic cavity
3. Apex
4. Four chambers
B. Layers
1. Pericardium
2. Myocardium
3. Endocardium
4. Septum
C. Structures to and from heart
1. Superior and inferior vena cava
2. Pulmonary artery and vein
3. Aorta
D. Chambers and valves
1. Atria (atrium)
2. Ventricles (ventricle)
3. Tricuspid valve
4. Mitral (bicuspid) valve
5. Pulmonary semilunar valve
6. Aortic semilunar valve
1H08.02
Analyze the function of the heart.
A. Four main functions of circulatory system
a. Pump
b. Blood transport system around body
c. Carries oxygen and nutrients to cells, carries away waste
products
d. Lymph system – returns excess tissue fluid to general circulation
B. Heart
a. Ave. 72 beats per minute, 100,000 beats per day
b. Superior and inferior vena cava bring deoxygenated blood to
right atrium
c. Cardiopulmonary circulation – circulation from the heart to the
lungs
d. Pulmonary artery takes blood from right ventricle to lungs
e. Pulmonary veins bring oxygenated blood from lungs to left atrium
f. Aorta takes blood from left ventricle to rest of body
g. Four heart valves permit flow of blood in one direction
C. Pump
a. Heart is a double pump
b. Right heart = right atrium  tricuspid valve  right ventricle 
pulmonary semilunar valve  pulmonary artery  lungs (for
oxygen)
c. Left heart = Lungs  pulmonary veins  left atrium  mitral
valve  left ventricle  aortic semilunar valve  aorta 
general circulation
D. Heart sounds (lubb dupp)
E. Electrical activity
a. SA (sinoatrial) node = pacemaker, sends out electrical impulses,
spreads impulse over atria and makes them contract
b. AV (atrioventricular) node = carries impulse to bundle of His
Summer 2005 H.1
c.
Bundle of His = conducting fibers in septum, divides into right
and left branches in ventricles to Purkinje fibers
d. Purkinje fibers = cause ventricles to contract
1H08.03
Analyze circulation and the blood vessels
A. Cardiopulmonary circulation – carries blood from heart to lungs
1. Oxygenated and deoxygenated blood
2. Oxygen/carbon dioxide exchange
B. General circulation
1. Coronary arteries
2. Aorta
3. Systemic circulation
C. Blood vessels
1. Arteries
a. Carry oxygenated blood away from the heart to the
capillaries
b. Elastic, muscular and thick-walled
c. Transport blood under very high pressure
2. Arterioles
3. Veins
a. Carry deoxygenated blood away from capillaries to heart
b. Less elastic and muscular than arteries
c. Thin walled, collapse easily when not filled with blood
d. Superior and inferior vena cava carry blood to heart
4. Venules
5. Capillaries
a. Smallest blood vessels
b. Only seen with microscope
c. Connect arterioles and venules
e. Walls are one-cell thick, allow for selective permeability
6. Valves – permit flow of blood only in direction of heart
7. Capillaries
8. Jugular vein – located in neck
9. Carotid artery – carries blood to brain
D. Blood pressure
1. Systolic – ave = 120 (Systole is contraction phase)
2. Diastolic – ave = 80 (Diastole is relaxation phase)
E. Pulse – alternating expansion and contraction of an artery as blood
flows through it
1. Brachial
2. Carotid
3. Femoral
4. Pedal
5. Popliteal
6. Radial
Summer 2005 H.2
1H08.04
Discuss characteristics and treatment of common cardiac
and circulatory disorders.
A. Heart diseases
1. Symptoms
a. Arrythmia (dysrrhythmia) – any change from normal heart
rate or rhythm
b. Bradycardia – slow heart rate (<60)
c. Tachycardia – rapid heart rate (>100)
2. Coronary artery disease
a. Angina pectoris – chest pain, lack of O2 to heart muscle,
treat with nitroglycerine
b. Edema – fluid in tissues, often caused by poor circulation
3. Myocardial infarction (MI, heart attack)
a. Lack of blood supply to myocardium
b. Symps – severe chest pain radiating to left shoulder, arm,
neck and jaw, nausea, diaphoresis, dyspnea
c. Rx – bedrest, oxygen, medication
d. Morphine for pain
e. Anticoagulant therapy to prevent further clots from forming
f. Surgery may be necessary
B. Vascular diseases
1. Aneurysm – ballooning of an artery, thinning and weakening
2. Arteriosclerosis – arterial walls thicken and lose elasticity
3. Atherosclerosis – fatty deposits form on walls of arteries and
block circulation
4. Hypertension
a. High blood pressure
b. Silent killer – usually no symptoms
c. Leads to strokes, heart attacks, kidney failure
d. Higher in African-Americans and post-menopausal women
e. Risk factors – smoking, overweight, stress, high fat diets,
family history
f. Treatment – relaxation, low fat diet, exercise, weight loss,
medication
5. Hypotension – low blood pressure, systolic <100
6. Embolism – traveling blood clot
7. Varicose veins
a. Swollen, distended veins
b. Heredity or due to poor posture, prolonged periods of
standing, physical exertion, age and pregnancy
C. Diagnosis and treatment
1. Electrocardiogram – electrical tracing of the heart
2. Coronary bypass – healthy vein from leg removed and attached
before and after the coronary obstruction, creating an alternate
route for blood supply to the myocardium
3. AED – automated external defibrillator
4. Defibrillation – electrical shock to bring the heart back to a
normal rhythm
5. CPR – cardiopulmonary resuscitation, used in presence of
cardiac arrest
6. Artificial pacemaker – when heart has conduction (electrical
impulse) defect, demand pacemaker fires when heart rate drops
below minimum, causes heart to contract
7. Angiogram – x-ray of blood vessel using dye
Summer 2005 H.3
Unit H: Circulatory System
Terminology List
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aorta
aortic semilunar valve
apex
arterioles
artery
atrium
Atrioventricular (AV) node
bicuspid/mitral
brachial
Bundle of His
capillaries
carotid
cardiopulmonary circulation
coronary arteries
deoxygenated
diastolic
endocardium
femoral
inferior vena cava
jugular
lubb dupp
myocardium
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Disorders and Related Terminology
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AED/defibrillation
aneurysm
angina pectoris
angiogram
arrhythmias
arteriosclerosis
artificial pacemaker
atherosclerosis
bradycardia
coronary bypass
coronary artery disease
CPR
edema
electrocardiogram (EKG and ECG)
embolus (embolism)
hypertension
hypotension
myocardial infarction
tachycardia
varicose veins
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oxygen/carbon dioxide exchange
oxygenated
pacemaker
pedal
pericardium
popliteal
pulmonary artery
pulmonary semilunar valve
pulmonary vein
pulse sites
purkinje fibers
radial
Sinoatrial (SA) node
septum
superior vena cava
systemic circulation
systolic
tricuspid
valves
veins
ventricle
venules
Functions
1. Pump
2. Blood transport system around body
3. Carries O2 and nutrients to cells, carries away
waste products
4. Lymph system – returns excess tissue fluid to
general circulation
Structure – Circulatory system involves:
 Heart
 Arteries
 Veins
 Capillaries
 Blood and lymph are part of circulatory
system
Major Blood Circuits
 General (Systemic) circulation
 Cardiopulmonary circulation
Summer 2005 H.5
Summer 2005 H.6
The Heart
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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
 PERICARDIUM – double layer of fibrous
tissue that surrounds the heart
 MYOCARDIUM – cardiac muscle tissue
 ENDOCARDIUM – smooth inner lining of
heart
Summer 2005 H.7
 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
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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
Summer 2005 H.8
TRICUSPID VALVE – between right atrium and
right ventricle
BICUSPID (MITRAL) VALVE – between left
atrium and left ventricle
Semilunar valves are located where blood
leaves the heart - PULMONARY SEMILUNAR
VALVE and AORTIC SEMILUNAR VALVE
Summer 2005 H.9
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)
Summer 2005 H.10
Blood Supply to the Heart – from CORONARY
ARTERIES
Heart Sounds = lubb dupp
Summer 2005 H.11
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
Summer 2005 H.12
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 contration
QRS = ventricular contract
T = ventricular relaxation
Summer 2005 H.13
CARDIOPULMONARY CIRCULATION – heart
and lungs
SYSTEMIC CIRCULATION – from the heart to
the tissues and cells, then back to the heart
Cardiopulmonary Circulation
“As the Blood Flows” Appendix MD08.03A
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
Summer 2005 H.14
Blood Vessels
Summer 2005 H.15
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
Summer 2005 H.16
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:
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BRACHIAL
CAROTID
RADIAL
POPLITEAL
PEDAL
Summer 2005 H.17
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)
Coronary Artery Disease
ANGINA PECTORIS – chest pain, caused by
lack of oxygen to heart muscle, treat with
nitroglycerin to dilate coronary arteries
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 build-up on
arterial walls, or arteriosclerosis – loss of
elasticity and thickening of wall.
 Amount of damage depends on size of area
deprived of oxygen
Summer 2005 H.18
 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
 Angioplasy and by-pass surgery may be
necessary
Heart 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.
PACEMAKERS
Demand pacemaker – fires only when heart rate
drops below programmed minimum
CPR – cardiopulmonary resuscitation, used in the
presence of cardiac arrest
Summer 2005 H.19
DEFIBRILLATION – electrical shock to bring the heart
back to a normal rhythm.
AED – automated external defibrillator
Disorders of the Blood Vessels
ANEURYSM – ballooning of an artery, thinning
and weakening
ARTERIOSCLEROSIS – arterial walls thicken,
lose elasticity
ATHEROSCLEROSIS – fatty deposits form on
walls of arteries
EMBOLISM – traveling blood clot
VARICOSE VEINS – swollen, distended veins –
heredity or due to posture, prolonged periods of
standing, physical exertion, age and pregnancy
Summer 2005 H.20
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
HYPOTENSION – low blood pressure, systolic
<100
Diagnostic Tests
CARDIAC CATHETERIZATION – catheter fed
into heart, dye injected, x-rays taken as dye
moves through coronary arteries
STRESS TESTS – determine how exercise
affects the heart, pt. on treadmill or exercise bike
while electrocardiogram recorded
ANGIOGRAM – x-ray of a blood vessel using
dye
Summer 2005 H.21