Transcript Chapter 10 Cardiovascular System

CHAPTER 10
Cardiovascular
System
Cardiovascular
System Overview
• Responsibilities of cardiovascular system
– Pumping blood to the body tissues and cells
– Supplying oxygen and nutrients to tissues and
cells
– Removing carbon dioxide and other waste
products of metabolism from tissues and cells
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Cardiovascular System
• Heart
– Center of the circulatory system
– Enclosed by pericardium
• Parietal pericardium
• Visceral pericardium
• Pericardial cavity
– Three layers of the heart
• Epicardium
• Myocardium
• Endocardium
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Heart
• Chambers
– Right atrium and left atrium
• Upper chambers
• Receiving chambers
– Right ventricle and left ventricle
• Lower chambers
• Pumping chambers
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Heart
• Partitions
– Interatrial septum
• Separates right and left sides of atria
– Interventricular septum
• Separates right and left sides of ventricles
5
Circulation Through the Heart
• Deoxygenated blood
– Enters right atrium from superior vena cava
• Brings blood from head, thorax, upper limbs,
and abdominal viscera
– Also enters right atrium from inferior vena
cava
• Brings blood from the trunk, lower limbs, and
abdominal viscera
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Circulation Through the Heart
• Deoxygenated blood travels:
– From right atrium through tricuspid valve into
right ventricle
– From right ventricle through pulmonary valve
into right and left pulmonary arteries
– From pulmonary arteries to lungs
• Pulmonary arteries are the only arteries that carry
deoxygenated blood
• Exchange of gases takes place in the lungs
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Circulation Through the Heart
• Oxygenated blood
– Enters left atrium from lungs via pulmonary
veins
• Pulmonary veins only veins in body that carry
oxygenated blood
– From left atrium through mitral valve into left
ventricle
– From left ventricle through aortic valve into
aorta
– From aorta to arteries to each body part and
region
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Circulation Through the Heart
• Pulmonary circulation
– Circulation of blood from the heart to the
lungs for oxygenation and back to the heart
• Systemic circulation
– Circulation of blood from the heart to all
parts of the body and back to the heart
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Circulation Through the Heart
• Coronary arteries
– Arise from aorta near its origin at left
ventricle
– Supply blood to heart muscle
– Heart muscle has a greater need for oxygen
and nutrients
• Heart uses approximately 3 times more oxygen
than other body organs
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Conduction System of the Heart
• Sinoatrial Node (SA Node) sets rhythm for
entire heart
– SA Node = pacemaker of the heart
– Impulse from SA node causes atria to contract
• Impulse travels from SA node to
Atrioventricular node (AV node)
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Conduction System of the Heart
• Impulse from AV node travels to ventricles
through Bundle of His
– Bundle of His divides into right and left bundle
branches
• Bundle branches terminate in Purkinje
fibers
– Purkinje fibers fan out into the muscles of the
ventricles
– Purkinje fibers cause ventricles to contract
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Supporting Blood Vessels
• Arteries
– Large, thick-walled vessels
– Carry blood away from the heart
• Arterioles
– Thinner walls than arteries
– Transport blood on to capillaries
• Capillaries
– Extremely thin walls = single layer
– Allow for exchange of materials between blood and
tissue fluid surrounding body cells
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Supporting Blood Vessels
• Venules
– Smallest veins
– Collect deoxygenated blood from cells for
transport back to heart
• Veins
– Thinner walls than arteries
• Thicker walls than capillaries
– Transport blood from venules to heart
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Cardiac Cycle
• One Cardiac Cycle = One Complete
Heartbeat
• Diastole
– Relaxation phase of heartbeat
– Ventricles relax and fill with blood
• Systole
– Contraction phase of heartbeat
– Ventricles contract
• Force blood out of heart
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Blood Pressure
• Blood Pressure
– Pressure exerted by blood on walls of arteries
• Systolic Pressure
– Maximum pressure reached within the
ventricles
• Diastolic Pressure
– Minimum pressure reached within the
ventricles
• Sphygmomanometer = blood pressure cuff
– Used to measure blood pressure
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Common Signs and Symptoms
• Symptoms that may indicate cardiovascular
problems
Anorexia
Anxiety
Bradycardia
Chest
pain
Cyanosis
Dyspnea
Edema
Fatigue
Fever
Headache
Nausea
Pallor
Palpitation
Sweat
Tachycardia
Vomiting
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Weakness
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PATHOLOGICAL CONDITIONS
Cardiovascular
System
Angina Pectoris
• Pronounced
– (an-JI-nah PECK-tor-is)
– (AN-jin-nah PECK-tor-is)
• Defined
– Severe pain and constriction about the heart,
usually radiating to left shoulder and down left
arm
• Creates feeling of pressure in anterior chest
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Cardiac Tamponade
• Pronounced
– (CAR-dee-ak TAM-poh-nod)
• Defined
– Compression of the heart caused by
accumulation of blood or other fluid within the
pericardial sac
• Accumulation of fluid in pericardial cavity prevents
ventricles from adequately filling or pumping blood
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Cardiomyopathy
• Pronounced
– (car-dee-oh-my-OP-ah-thee)
• Defined
– Disease of the heart muscle itself, primarily
affecting pumping ability of the heart
• Noninflammatory disease of the heart
• Results in enlargement of the heart and
dysfunction of the ventricles of the heart
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Congestive Heart Failure
• Pronounced
– (con-JESS-tiv heart failure)
• Defined
– Condition in which pumping ability of heart is
progressively impaired to the point that it no
longer meets bodily needs
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Congestive Heart Failure
• Left-sided cardiac failure
– Left ventricle unable to pump blood that
enters from the lungs
– Characteristics:
•
•
•
•
•
•
Dyspnea
Moist sounding cough
Fatigue
Tachycardia
Restlessness
Anxiety
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Congestive Heart Failure
• Right-sided cardiac failure
– Right side of heart cannot empty blood received from
venous circulation
– Characteristics:
• Edema of lower extremities (pitting edema)
• Weight gain
• Enlargement of liver (hepatomegaly)
• Distended neck veins
• Ascites
• Anorexia
• Nocturia
• Weakness
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Coronary Artery Disease
• Pronounced
– (KOR-oh-nah-ree AR-ter-ee dih-ZEEZ)
• Defined
– Narrowing of the coronary arteries to the
extent that adequate blood supply to the
myocardium is prevented
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Coronary Artery Disease
• Treatments for occluded coronary
arteries
– Medications
– Percutaneous Transluminal Coronary
Angioplasty (PTCA)
– Directional Coronary Atherectomy
– Coronary Bypass Surgery = Coronary
Artery Bypass Graft (CABG)
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Endocarditis
• Pronounced
– (en-doh-car-DYE-tis)
• Defined
– Inflammation of the membrane lining of the
valves and chambers of the heart
• Caused by direct invasion of bacteria or other
organisms
• Leads to deformity of valve cusps
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Hypertensive Heart Disease
• Pronounced
– (high-per-TEN-siv heart dih-ZEEZ)
• Defined
– Heart disease as a result of long-term
hypertension
• Heart must work against increased resistance due
to increased pressure in the arteries
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Mitral Valve Prolapse
• Pronounced
– (MY-tral valve proh-LAPS)
• Defined
– Drooping of one or both cusps of the mitral
valve back into the left atrium during
ventricular systole
• Results in incomplete closure of the valve and
mitral insufficiency
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Myocardial Infarction
• Pronounced
– (my-oh-CAR-dee-al in-FARC-shun)
• Defined
– Condition caused by occlusion of one or
more of the coronary arteries = destruction
of myocardial tissue
– Heart attack
• Life-threatening condition
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Myocarditis
• Pronounced
– (my-oh-car-DYE-tis)
• Defined
– Inflammation of the myocardium
• May be viral or bacterial infection
• May be result of systemic disease
• May be caused by fungal infections, serum
sickness, or chemical agent
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Pericarditis
• Pronounced
– (per-ih-car-DYE-tis)
• Defined
– Inflammation of the pericardium (saclike
membrane) that covers the heart muscle
• May be acute or chronic
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Rheumatic Fever
• Pronounced
– (roo-MAT-ic fever)
• Defined
– Inflammatory disease that may develop as a
delayed reaction to insufficiently treated
Group A beta-hemolytic streptococcal
infection of the upper respiratory tract
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PATHOLOGICAL
CONDITIONS
Blood Vessels
Aneurysm
• Pronounced
– (AN-yoo-rizm)
• Defined
– Localized dilatation of an artery formed at a
weak point in the vessel wall
• Weakened area balloons out with each pulsating of
artery
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Arteriosclerosis
• Pronounced
– (ar-tee-ree-oh-skleh-ROH-sis)
• Defined
– Arterial condition in which there is thickening,
hardening and loss of elasticity of the walls of
arteries (hardening of the arteries)
• Results in decreased blood supply, especially to
lower extremities and cerebrum
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Hypertension
• Pronounced
– (high-per-TEN-shun)
• Defined
– Condition in which the patient has a higher
blood pressure than judged to be normal
• Blood pressure persistently exceeds 140/90 mmHg
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Hypertension
• Essential hypertension
– Accounts for 90 percent of all hypertension
– No single known cause
• Secondary hypertension
– Due to underlying cause
• Malignant hypertension
– Severe and rapidly progressive
– Diastolic pressure higher than 120 mmHg
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Peripheral
Arterial Occlusive Disease
• Pronounced
– (per-IF-er-al ar-TEE-ree-al occlusive
disease)
• Defined
– Obstruction of the arteries in the extremities
(predominantly the legs)
• Leading cause = atherosclerosis
• Classic symptom = intermittent claudication
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Raynaud’s Phenomenon
• Pronounced
– (ray-NOZ phenomenon)
• Defined
– Intermittent attacks of vasoconstriction of the
arterioles
• Causes pallor of the fingers or toes, followed by
cyanosis, then redness, before returning to normal
color (white-blue-red)
• Initiated by exposure to cold or emotional
disturbance
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Thrombophlebitis
• Pronounced
– (throm-boh-fleh-BY-tis)
• Defined
– Inflammation of a vein associated with the
formation of a thrombus (clot)
• Usually occurs in an extremity, most frequently a
leg
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Thrombophlebitis
• Superficial Thrombophlebitis
– Usually obvious
– Accompanied by cordlike or thready
appearance to the vessel
• Deep Vein Thrombosis (DVT)
– Occurs primarily in lower legs, thighs, and
pelvic area
– Characterized by aching or cramping pain in
legs
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Varicose Veins
• Pronounced
– (VAIR-ih-kohs veins)
• Defined
– Enlarged, superficial veins
– Twisted, dilated veins with incompetent valves
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Varicose Veins
• Treatment
– Rest and elevation of affected extremity
– Use of elastic stockings
– Sclerotherapy
• Injection of a chemical irritant into the varicosed
vein (sclerosing agent)
– Vein stripping
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Venous Insufficiency
• Pronounced
– (VEE-nuss in-syoo-FISH-in-see)
• Defined
– An abnormal circulatory condition
characterized by decreased return of venous
blood from the legs to the trunk of the body
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PATHOLOGICAL
CONDITIONS
Congenital
Heart Diseases
Coarctation of the Aorta
• Pronounced
– (koh-ark-TAY-shun of the aorta)
• Defined
– Congenital heart defect characterized by a
localized narrowing of the aorta
• Results in increased blood pressure in upper
extremities and decreased blood pressure in lower
extremities
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Patent Ductus Arteriosus
• Pronounced
– (PAY-tent DUCK-tus ar-tee-ree-OH-sis)
• Defined
– Abnormal opening between the pulmonary
artery and the aorta caused by failure of fetal
ductus arteriosus to close after birth
• Defect seen primarily in premature infants
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Tetralogy of Fallot
• Pronounced
– (teh-TRALL-oh-jee of fal-LOH)
• Defined
– Congenital heart anomaly that consists of four
defects
•
•
•
•
Pulmonary stenosis
Interventricular septal defect
Dextraposition of aorta (shifts to the right)
Hypertrophy of right ventricle
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Transposition
of the Great Vessels
• Pronounced
– (tranz-poh-ZIH-shun of the great vessels)
• Defined
– Condition in which the two major arteries of
the heart are reversed in position
• Results in two non-communicating circulatory
systems
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PATHOLOGICAL CONDITIONS
Arrhythmias
Atrial Flutter
• Pronounced
– (AY-tree-al flutter)
• Defined
– Condition in which the contractions of the atria
become extremely rapid, at the rate of
between 250 to 400 beats per minute
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Fibrillation (Atrial Fibrillation)
• Pronounced
– (atrial fih-brill-AY-shun)
• Defined
– Extremely rapid, incomplete contractions of
the atria resulting in disorganized and
uncoordinated twitching of the atria
• Rate of contractions may be as high as 350 to 600
beats per minute
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Fibrillation
(Ventricular Fibrillation)
• Pronounced
– (ventricular fih-brill-AY-shun)
• Defined
– Rapid, tremulous (quivering like a bowl of JellO) and ineffectual contractions of the ventricles
•
•
•
•
•
No audible heartbeat
No palpable pulse
No respiration
No blood circulation
If prolonged, will lead to cardiac arrest
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Heart Block (AV)
• Pronounced
– (Heart Block)
• Defined
– An interference with the normal conduction of
electric impulses that control activity of the
heart muscle
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Ventricular Tachycardia
• Pronounced
– (ven-TRIK-yoo-lar tak-ee-CAR-dee-ah)
• Defined
– Condition in which the ventricles of the heart
beat at a rate greater than 100 beats per
minute
• Characterized by three or more consecutive
premature ventricular contractions
– Also known as V-tach
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DIAGNOSTIC
TECHNIQUES, TREATMENTS
AND PROCEDURES
Cardiovascular
System
Diagnostic Techniques,
Treatments, and Procedures
• Angiography
– X-ray visualization of internal anatomy of
heart and blood vessels after introducing a
radiopaque substance (contrast medium)
– Promotes imaging of internal structures that
are otherwise difficult to see on X-ray film
• Substance is injected into an artery or a vein
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Diagnostic Techniques,
Treatments, and Procedures
• Cardiac catheterization
– Diagnostic procedure in which a catheter is
introduced into a large vein or artery, usually
of an arm or a leg, and is then threaded
through the circulatory system to the heart
• Used to obtain detailed information about the
structure and function of the heart chambers,
valves, and the great vessels
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Diagnostic Techniques,
Treatments, and Procedures
• Cardiac Enzymes Test
– Tests performed on samples of blood
obtained by venipuncture to determine the
presence of damage to the myocardial muscle
• (CAT) Computed Axial Tomography
– Diagnostic X-ray technique that uses ionizing
radiation to produce a cross-sectional image
of the body
• Often used to detect aneurysms of the aorta
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Diagnostic Techniques,
Treatments, and Procedures
• Echocardiography
– Diagnostic procedure for studying the
structure and motion of the heart
• Useful in evaluating structural and functional
changes in a variety of heart disorders
• Electrocardiogram (EKG, ECG)
– Graphic record of the electrical action of the
heart as reflected from various angles to the
surface of the skin
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Diagnostic Techniques,
Treatments, and Procedures
• Exercise stress testing
– Means of assessing cardiac function, by
subjecting the patient to carefully controlled
amounts of physical stress, for example, using
the treadmill
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Diagnostic Techniques,
Treatments, and Procedures
• Holter monitoring
– Small, portable monitoring device that makes
prolonged electrocardiograph recordings on a
portable tape recorder
• Continuous EKG (ambulatory EKG) is recorded on
a magnetic tape recording while the patient
conducts normal daily activities
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Diagnostic Techniques,
Treatments,and Procedures
• Event monitor
– Similar to the Holter monitor in that it also
records the electrical activity of the heart while
patient goes about usual daily activities
– Can be used for a longer period of time than a
Holter monitor
• Usually a month
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Diagnostic Techniques,
Treatments, and Procedures
• Implantable Cardioverter Defibrillator (ICD)
– Small, lightweight, electronic device placed
under the skin or muscle in either the chest or
abdomen to monitor the heart’s rhythm
– If abnormal rhythm occurs, the ICD helps
return the heart to its normal rhythm
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Diagnostic Techniques,
Treatments, and Procedures
• Magnetic Resonance Imaging (MRI)
– Use of strong magnetic field and
radiofrequency waves to produce imaging that
is valuable in providing images of the heart,
large blood vessels, brain, and soft tissue
• Used to examine the aorta, to detect masses or
possible tumors, and pericardial disease
• Can also show the flowing of blood and the beating
of the heart
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Diagnostic Techniques,
Treatments, and Procedures
• Positron Emission Tomography (PET)
– Computerized x-ray technique that uses
radioactive substances to examine the blood
flow and the metabolic activity of various body
structures, such as the heart and blood
vessels
• Patient is given doses of strong radioactive tracers
by injection or inhalation
• Radiation emitted is measured by the PET camera
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Diagnostic Techniques,
Treatments, and Procedures
• Serum Lipid
– Test that measures the amount of fatty
substances (cholesterol, triglycerides, and
lipoproteins) in a sample of blood obtained by
venipuncture
• Thallium Stress
– Combination of exercise stress testing with
thallium imaging to assess changes in
coronary blood flow during exercise
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