Transcript Cardiovascular day

CARDIOVASCULAR SYSTEM
Blood pressure
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Hypotension
Hypertension
Factors that effect BP
Cardiac output
 ASHSD
 Blood volume
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Shock:
Hypovolemic
 Vascular
 Cardiogenic
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Terminology
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Palpitations
Flutters
Chest pain
Shortness of breath (SOB)
Intermittent claudication
ECG/EKG
Echocardiogram
Doppler
Arteriography
Cardiovascular System
Chapter 18/19
Physiology
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Closed circulatory system of vessels powered by a
pump – the heart
Works from in-utero to death
Flow and pressure of blood changes due to
environmental needs
8-10 pints of blood in most adults
Heart location
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Mediastinum of the thorax
Behind the sternum
Front of vertebral column
Between the 2nd to 6th ribs
Tilted slightly to the left – 2/3 mass
Posteriorly, rests against 5th – 8th vertebra
Apex on diaphragm – 5th-6th ribs + L clavicle
Upper border – below 2nd rib
Size and shape
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Size of fist
By age 25, heart reaches mature form – M – 310 g
an F 225g
Tall, thin individuals have elongated heart
Short, stocky individuals have wider heart
4 ¾” length – 3 ½” wide – 2 ½” deep
Coverings
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Pericardium – two parts – fibrous / serous
epicardium which attaches to blood vessels
emerging from the top of the heart
Sac – fibrous tissue lined with serous membrane
Pericardial space – lubricating fluid – pericardial
fluid to reduce friction
Layers summarized pg 557
Layers
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Epicardium/pericardium
 Parietal
layer fibrous outer covering
 Visceral layer– serous membrane attached to the
myocardium
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Myocardium
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Endocardium,
Epicardium
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Surrounds the heart
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Protection
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Reduction of friction
Myocardium
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Major portion/mass
Cardiac muscle cells exclusively found in the heart
These cells can pass action potential between each
other which assists with electrical movement to
produce contraction
Autorhythmic – contract on their own in an
alternating contraction /relaxation cycle
Pump to move blood
Endocardium
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Inner most lining
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Endothelium
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Very smooth
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Reduces the possibility of RBC destruction
Chambers
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Four
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Atria/atrium – receiving chambers from veins
 Foramen
ovale – passageway between the 2 atria so
that the lungs are bypassed in the fetus
 Fossa ovale – scar tissue where foramen ovale existed
until closed within 6-9 mo. After birth
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Ventricles/ventricle – pumping chambers
Valves
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Four
Atrioventricular
 Tricuspid
 Bicuspid
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/mitral
Semilunar
 Pulmonary
 Aortic
What is the purpose of the chordae
tendineae?
Anchors the mitral and tricuspid valves to the
small papillary muscles of the ventricles
Types of blood vessels
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Artery – carries blood away from the heart and
normally carries oxygenated blood
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Vein – carries blood toward the heart and normally
carries deoxygenated blood
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arterioles
venules
Capillary – gas exchange occurs
Layers
Three
layers
Tunica adventitia: outer layer of tough
fibrous tissue
Tunica media: smooth muscle which
allows vessels to constrict/dilate
Tunica intima: smooth, inner elastic layer
(lumen = internal diameter)
Arteries
 Carry
blood AWAY from the heart
 All BUT pulmonary arteries carry oxygenated blood
 Aorta: largest artery; 1 inch in diameter
 Arterioles: smallest arteries
 Coronary arteries: most important; supply blood to the
heart muscle
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Left and right main coronary artery
Left coronary artery - left anterior descending - left circumflex
branch
Right coronary artery - right atrium and right ventricle
Veins
 Carry
blood TOWARD the heart
 All BUT pulmonary veins carry deoxygenated blood
 Layers much thinner, less elastic
 Series of internal valves that work against the flow of
gravity to prevent reflux
 Superior and inferior vena cava: largest veins
 Venules: smallest veins
Capillaries
Tiny,
microscopic vessels
Walls one cell layer thick
Function: to transport and diffuse
essential materials to and from the
body’s cells and the blood
Blood supply
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5 coronary arteries
Heart and blood vessel disease #1 cause of death
in U.S. – Texas is a leader!
Incapacitation occurs
Arteriosclerosis
Atherosclerosis
Read bullets pg 564
Myocardial infarction causes ischemia – death
What is the meaning of
anastomosis?
Detour around diseased or clotted areas
Tracing a drop of blood through the
body
 Superior
and inferior vena cava
 Right atrium
 Tricuspid valve
 Right ventricle
 Pulmonary semilunar valve
 Pulmonary arteries
 Lungs ( O2 and CO2 exchange = external respiration)
 Pulmonary veins
 Left atrium
 Bicuspid/Mitral valve
 Left
ventricle
 Aortic semilunar valve
 Aorta - all parts of body via arteries
 Arterioles
 Capillaries of individual tissues (O2 and CO2 exchange
= internal respiration)
 Venules
 Veins
 Superior and inferior vena cava
Conduction circuits of the heart
 Pulmonary
circuit: transport of blood from the right side
of the heart to the lungs and then back to the left side of
the heart
 Systemic circuit: transport of blood from the left side of
the heart to all parts of the body and then back to the
right side of the heart
 Coronary circuit: transport blood from the left side of the
heart to the heart tissues and back to the right side of the
heart
Conductivity
 Enables
heart to contract rhythmically and continuously
without motor nerve impulses
 Arrhythmia: myocardial cells leak sodium faster than the
SA node - irregular heart beat
 SA (sinoatrial) node: pacemaker located where the
superior and inferior vena cava enter the right atrium
 AV (atrioventricular) node: sends impulses to ventricles
 Bundle of His/bundle branches: in septum
 Purkinje fibers: in heart wall to distribute nerve impulses
Cardiac cycle
 One
(1) contraction (systole = 0.3 seconds) + one (1)
relaxation (diastole = 0.5 seconds) at 75 beats per
minute
 Initiation of contraction - SA node (group of nerve cells);
impulse spreads out over both atria causing them to
contract together to force blood into both ventricles
 Impulse from SA node sent to AV node (between atria in
septum)
 Impulse
from AV node sent to nerve fibers in septum
(bundle of His) which transmit the impulse via the right
and left bundle branches to the Purkinje fibers - cause
ventricles to contract together and force blood out of the
aorta and pulmonary arteries to the body and the lungs
 Shift of ions along the conduction system = action
potential
 Periods of rest = polarization
 Periods of activity = depolarization - when impulse is
transmitted and repolarization - when slow shift back to
polarization occurs
Blood pressure
 Systole:
maximum pressure formed during a
ventricular contraction
 Diastole: minimum pressure during ventricular
relaxation (atrial contraction)
 Measured in mm of Hg
 BP
= CO x PR (blood pressure = cardiac output x
peripheral resistance)
 Normals
 Systolic
= 100 - 140
 Diastolic = 60 - 90
 Hypotension:
Systolic < 90
 Hypertension: Systolic > 150 and/or Diastolic > 90
FYI
 Factors
Affecting BP
 Cardiac
output
 Peripheral resistance
 Blood volume
 Circulatory
Shock
 Hypovolemic
shock
 Vascular shock
 Cardiogenic shock
Causes of peripheral resistance?
Abnormalities
 Arteriosclerosis:
hardening of the arteries
 Atherosclerosis
Fatty deposits on the walls of the arteries
 Factors: increased blood lipids, high blood pressure, smoking,
obesity, physical inactivity, tension
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 Hypertension
90% = essential hypertension - no specific cause
 10% = symptom of another disease i.e. adrenal tumor, kidney
disease
 Increases workload of the heart
 Leads to hypertrophy of left ventricle then heart failure
 Accelerates development of atherosclerosis
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 Ischemic
Heart Disease
Oxygen supply to heart inadequate
 Atherosclerosis is major cause
 Can lead to
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Angina pectoris: condition in which coronary arteries are temporarily
blocked - reduced blood supply to heart muscle - chest pain
Heart attack: cessation of normal cardiac contraction (cardiac
arrest)
Myocardial infarction: necrosis (death) of heart muscle due to severe
prolonged ischemia
Sudden death: heart stops of ventricular
fibrillation occurs
Cardiac Arrhythmias
Abnormality in rate, rhythm, or conduction of heart beat
 Bacterial Endocarditis
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Inflammation of the internal lining of the heart
Also involves the heart valves
Valvular Heart Disease – (MVP)
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Involves abnormalities of the heart valves
Especially mitral and aortic valves
Leading cause = rheumatic fever with hypersensitivity reaction to
streptococcus antigens
Heart valves are scarred
Treatment - valve replacement
 Congenital
Heart Disease
Defects in the heart that occurred during embryologic and fetal
development
 Involves defective communication between the chambers,
malformation of valves, and malformation of septa
 Cyanotic: inability of individual to get adequate blood
oxygenation due to extensive cardiac abnormalities that cause
blood to be shunted away from lungs
 Example: “Blue Babies”; failure of foramen ovale to close or
transposistion of great arteries or patent ductus arteriosus
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Some association with pregnant mother having
German measles (rubella
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Congestive Heart Failure (CHF)
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Pumping action of heart diminished
Fluid accumulates and is retained in tissues
Compensations
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Increased heart rate, greater force of contraction
Retention of fluid by kidneys
Enlargement of heart
Cor Pulmonale
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Hypertrophy of right ventricle due to hypertension in pulmonary
circulation
Increased bp in lungs - reduction in blood flow and increased
resistance in lungs - pulmonary hypertension - increased pressure in
pulmonary arteries - blood backs up into right ventricle - hypertrophy
 Peripheral
Arterial Disease - Decreased blood flow
to peripheral vessels
 Varicose Veins: enlarged veins which can be
inflamed
 Hemorrhoids: varicose veins of rectal and anal
area
 Aneurysm: weak section in wall of artery ballooning out - rupture
 Phlebitis: inflammation of a vein
 Thrombus:
blood clot that stays where it is formed
 Stroke (CVA): brain infarct; caused by decreased
oxygen supply to brain due to blood clot or
hemorrhage
 Raynaud’s Disease
 Esophageal Varices
 Tetralogy of Fallot
Diagnostic procedures:
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History and physical
 Angina,
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SOB, fatigue, dizzy, edema, claudication
EKG – electrical tracing
Phonocardiogram – EKG with heart sounds
Echocardiogram – sound wave – size and movement
Doppler ultrasound – measures blood flow
Arteriography – radiopaque study – blood flow
Cardiac catheterization – dye injected – flow
Pulse
Pulse - pg 620
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Pulse wave
Palpation:
 Radial
 Temporal
 Carotid
 Facial
 Brachial
 Popliteal
 Posterior
tibial
 Dorsalis pedis
Pressure points – pg 621
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Used to control arterial bleeding
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Caution to never stop all blood flow
Circulatory shock
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Cardiogenic
Hypovolemic
Neurogenic
Anaphylactic
Septic - TSS
TMT
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Pacemaker
Aorta
Cardiac cath
Occlusion
Stroke vs heart attack
List the differences
Esophageal varices
EV 7 d post-op
CARDIAC QUESTIONS?