Transcript cardiovascular system - Valhalla High School

Chapter 11
CARDIOVASCULAR SYSTEM
The heart is a muscle that pumps blood.
Blood vessels carry the blood.
PRACTITIONERS
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Cardiology (cardi/o = heart)
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Cardiologist
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Interventional cardiologist
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Performs procedures and inserts devices
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Cardiac surgeon
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Cardiovascular surgeon (vascul/o = vessel)
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Treats vessels
HEART FACTS
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Located in center of thoracic cavity
Between the lungs & behind the sternum
 Size of your fist
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Points (bottom, apex) left
Three-layered wall
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Pericardium – outer layer of fibrous tissue
Myocardium – middle layer of thick muscle
(my/o)
Endocardium – inner layer of epithelial cells
Anatomy & Physiology of Heart
and Surrounding Structures
HEART ANATOMY
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Septum (sept/o = partition)
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4 chambers
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Separates the two sides of the heart (L & R)
Atria (atrium) – 2 upper chambers (atri/o)
Ventricles – 2 lower chambers (ventricul/o)
Valves connect upper and lower chambers
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Bicuspid valve – left side (bi = two)
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Also called mitral valve
Tricuspid valve – right side
Open and close together
Prevent blood from flowing back into the atria
HEART ANATOMY (con’t)
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2 additional valves in ventricles
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Pulmonary valve –opening of pulmonary artery
Aortic valve –opening of the aorta
Work at the same time
Name the valves
(#5 is not a valve)
1. Pulmonary Valve
2. Tricuspid Valve
3. Mitral (Bicuspid)
Valve
4. Aortic Valve
5. Heart Apex
Check your labels!
INTERNAL VIEW OF HEART
HEART ACTION
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Heart contracts to pump blood
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Systole – contraction phase
Diastole – relaxation phase
Heartbeat consists of:
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Contraction by atria, then ventricles
Together = cardiac cycle
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Average heart beat is 72/min
Cardiac output = volume of blood pumped in 1
min.
Regulation of Cardiac Cycle
- controlled by the cardiac center within the
medulla oblongata. The cardiac center
signals heart to increase or decrease its rate
according to many factors that the brain
constantly monitors.
•Muscle Activity
•Body Temperature
•Blood ion levels (potassium & calcium)
BLOOD FLOW THROUGH THE
HEART
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Pulmonary circulation
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Right side of heart carries blood to lungs
Return of de-oxygenated blood from the body
Blood flow to pick up oxygenated blood in
lungs
Systemic circulation
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Left side of heart carries blood to body
Oxygenated blood returns from lungs
Oxygenated blood sent out to body cells via
aorta
CONDUCTION SYSTEM
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Works like an electrical circuit
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Signal flows from
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SA node –begins process
Pacemaker of heart
 Determines rhythm
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AV node
Right and left bundle branches (Bundle of His)
Purkinje fibers
CONDUCTION SYSTEM
Parts of the Blood
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Plasma (55% of the blood)
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A straw-colored fluid which is about 90% water and
10% dissolved gases, salts, nutrients, enzymes,
hormones, waste products and plasma proteins
Cells (45% of the blood)
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RBC’s
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Most numerous (5-6 million)
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WBC’s (leukocytes) (4,000-10,000)
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Contain hemoglobin, which is the iron-containing protein
that binds oxygen
They are the army of the circulatory system
May increase dramatically when the body is fighting an
infection
Platelets (250,000 – 400,000)
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Help in blood clotting by clumping together at the injury
to prevent blood from flowing out of the cut
BLOOD VESSELS
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Vessel
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Vas/o
Angi/o
Arteries (arteri/o)
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Carries blood away from the heart
Largest artery is the aorta
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Get smaller – form arterioles (arteriol/o)
Arterioles change into capillaries
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Nutrients and gases are exchanged
VESSELS (con ‘t)
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Venous system
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Carries blood back to heart
Capillaries form into tiny venules
Veins (ven/o , phleb/o)
Largest = superior and inferior venae cavae
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Veins have one-way valves to prevent back flow of blood
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Lumen: central opening of vessel
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Pulse: artery expanding and contracting
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Arterial system helps maintain body’s blood pressure:
constrict and dilate to keep an even pressure gradient
PULSE POINTS (palpable pulses)
HEART FACTS
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Heart has a circulatory system to nourish the heart
muscle
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Called coronary circulation (coron/o = circle or crown)
Right and left coronary arteries
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Decreased blood flow leads to heart tissue death
Myocardial infarction (heart attack)
Blood pressure (BP)
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Hypertension = Elevated BP
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Hypotension
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Increased resistance in vessels – Poor blood flow
Too little blood flowing to organs
Read: systolic pressure (#) /diastolic pressure (#)
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Goal is ~ 120/80
WELLNESS & ILLNESS
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Listen to the heart with a stethoscope
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Lub - dub = S1, S2
S1 – closing of AV valves as ventricles contract
(systole)
 S2 – closing of semilunar valves closing in relaxation
diastole
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Listen to specific areas of heart for:
Abnormal heart sounds
 Valve defects
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Heart Sounds - Opening and Closing of
Valves, "Lub Dub"
Stethoscope - instrument to
listen and measure heart
sounds
FETUSES & NEWBORNS
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At birth, lungs inflate and aeration begins
Congenital heart defects
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Impaired cardiac function
ASD: opening between atrium
VSD: opening between ventricles
PDA: persistent fetal circulation
Coarctation of aorta: narrowing of descending
portion of aorta
CHILDREN
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Murmurs
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Innocent murmurs
Functional murmurs
ADULTS –Risk Factors
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Risk factors for heart disease
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Cannot be controlled:
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Age, family history, gender
Can be modified/treated/controlled:
Smoking
 Physical Activity
 Body mass Index: keep less than 25 (weight)
 Blood pressure: keep less than 120/80
 Blood glucose: keep less than 140 (random)
 Cholesterol
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Keep total below 200
HDL, LDL, triglyceride levels
ADULTS
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PROBLEMS
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Arteriosclerosis (scler/o = hardening)
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Affects walls of small vessels
Angina pectoris
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Severe pain in chest (and may radiate)
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Decreased blood flow to heart
Abnormalities in vessels
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Aneurysm
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Ballonlike swelling of an artery
Atherosclerosis (ather/o = pasty material)
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Blockage caused by lipid deposits
SENIORS
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Aging changes
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Elevated BP
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Coronary heart disease
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Poor pumping ability of heart – poor body perfusion
Arrhythmias (rhythm = beat)
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General term
Congestive heart Failure
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Normal calcification of vessels
Irregular heart rhythm
Ectopic beats (ecto = outer)
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Heartbeat outside regular rate and rhythm
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Outside SA node regulation
GENERAL TERMS
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Bradycardia (brady = slow)
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Tachycardia (tachy = rapid)
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Cardiomegaly (megal/o = enlargement)
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Vasoconstriction
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Vasodilation
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Narrowing of a vessel
Widening of a vessel
Varicose Vein
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Dilated and twisted veins, usually in legs
TESTS
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Blood testing − lipid risk panel
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Electrocardiogram (ECG)
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Ultrasound of heart
EKG
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Tracing electrical activity of the heart
Identify heart muscle changes
Interpreting EKGs
An EKG is printed on paper covered with a
grid of squares.
Notice that five small squares on the paper
form a larger square. The width of a single
small square on EKG paper represents 0.04
seconds.
- A common length of an EKG printout is 6
seconds; this is known as a "six second
strip."
HEART RHYTHMS
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EKG tracings
PROCEDURES
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Interventional cardiology
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Cardiac catheterization (angiogram)
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To determine flow of blood through heart and main
vessels
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Balloon Angioplasty (PTCA)
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Use catheter and dye
Balloon catheter inserted into blocked coronary artery,
then inflated to push plaque against vessel walls
Endarterectomy
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Removal of plaque from an artery
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Common in carotids
Coronary bypass graft (CABG)
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Cardiac vessels replaced with healthy ones
DRUGS
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Improve function of heart muscle
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Eliminate access fluid
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Anticoagulants
Decrease blood pressure
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Diuretics (Lasix) – CHF
Ensure flow of blood through vessels
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Beta-blockers, antiarryhythmics, Digoxin
Antihypertensives
Decrease serum cholesterol levels
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Hypolipidemics