Purple Passion

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Cardio-vascular system
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Functions

• Transport nutrients, gases, wastes and hormones
• Maintain balance of fluids in body
• Protection from disease
• Regulate body temperature
• Blood clotting

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Characteristics of Blood vessels

• Arteries
• from the heart outward
• large to small
• Flexible
• collect cholesterol

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Characteristics of Blood vessels

• Veins
• into the heart
• small to large
• have valves to prevent backflow of blood

• Capillariesconnecting arteries to veins
• one cell wide
• responsible for the exchange of blood gases.

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Cardiovascular systemthe Heart

• Location, size and position
• Located between the lungs in the lower portion of
  your chest
• Triangular organ about the size of your fist

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Heart cont

• Atria are smaller and have thinner walls than the
  ventricles

• Chambers
• Hollow organ
• Upper two chambers atriareceive the blood
• Lower two chambers ventriclesdischarge blood

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Heart cont

• Heart is composed of myocardium (cardiac muscle)
• Interatrial septum separates the atria
• Interventrical septum separates the ventricles

• All four chambers are lined with endocardium

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Heart cont

• Pericardiumcovering of heart consisting of two
  layers of fibrous tissue with space in between

• Epicardiumlike skin on an apple
• Parietal pericardiumloose baggy fit so that the
  heart can beat

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Heart action

• Muscular pumping device distributing blood to all
  parts of the body
• Atria contract first followed by the ventricle
  contraction
• When heart is contracted, it is in systole
• When heart is relaxed, it is in diastole

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Valves of the heart

• AV valves prevent backflow of blood into atria
  when the ventricles contract

• Atrioventricular (AV) valves separate atria from
  ventricles
• Bicuspid AV valve on the left side
• Tricuspid AV valve on the right side

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Valves of the heart

• Chordae tendinae attach valves to wall of heart

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Valves of the heart

• Semilunar (SL) valves are located between the
  ventricles and the large arteries
• Pulmonary SL valvefound at beginning of
  pulmonary artery (leads to lungs) and prevents
  backflow into ventricle as blood goes to lungs

• Aortic SL valvefound at beginning of aorta
  preventing backflow into ventricle as blood
  travels to aorta (and out to rest of the body)

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Sounds of the heart

• LubAV valves closing as the ventricles contract
  (longer and lower pitch)
• DupSL valves closing as ventricles relax

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External Heart Diagram
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Heart as a pump

• The heart acts as two separate pumps.
• The right and left sides work together (at the
  same time) but perform different functions!

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Pulmonary Circulation

• Blood enters right atrium through the superior
  and inferior vena cava (O2 poor blood from body)
• Blood pumped through tricuspid AV valve to right
  ventricle
• Right ventricle contracts, sending blood through
  the pulmonary artery to lungs (O2 gained, CO2
  lost)

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Systemic Circulation

• O2 rich blood returns to left atrium through
  pulmonary veins
• Blood pumped through bicuspid AV into left
  ventricle
• Left ventricle contracts sending blood to rest of
  body via aorta

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Blood supply to heart

• Aortas first two branches are the right and left
  coronary arteries
• Coronary bypass surgerycoronary artery(ies) that
  are replaced by veins (often from the leg) after
  they are damaged/blocked to restore blood supply
  to the heart.

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Hepatic Portal Circulation

• Veins from the spleen, stomach, pancreas,
  gallbladder, and intestine do not pour blood
  directly into the VC, they send their blood to
  the liver via the hepatic portal vein
• Blood must then pass through the liver before it
  reenters the regular venous return path to heart

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Hepatic Circulation cont

• Blood leaves the liver by way of the hepatic
  veins which drain into the inferior VC
• This detour through the liver serves a valuable
  purpose
• When a meal is being absorbed, the blood in the
  portal vein has higher than normal glucose
  levels. The liver cells remove the excess
  glucose and store it as glycogen.
• Liver cells also remove and detoxify various
  toxins in blood

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Fetal Circulation

• Specialized blood vessels must carry fetal blood
  to the placenta and return it to the mothers
  system. Three vessels accomplish this purpose
• 2 small umbilical arteries (O2 poor blood) and
• A single, larger umbilical vein (O2 rich blood)

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Fetal Circulation

• Ductus venosus (a cont of umbilical vein) serves
  as a shunt allowing most of the blood returning
  from placenta to bypass the fetal liver and empty
  directly into the inferior VC

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Fetal Circulation

• Foramen ovaleshunts blood directly from the
  right atrium to the left atrium
• Ductus arteriosusconnects aorta and pulmonary
  artery

• Two other structures allow most of the blood to
  bypass developing lungs (as they are collapsed
  until birth anyway)

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Fetal Circulation

• At birth, as baby takes its first deep breaths,
  the cardiovascular system is subjected to
  increased pressure. The result is the closure of
  the foramen ovale and the rapid collapse of the
  umbilical bvs, ductus venosus and ductus
  arteriosus

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Physiology of Circulation

• Cardiac muscle fibers can contract rhythmically
  on their own, but need electrical impulses to be
  effected (coordinated)
• Intercalated disks are the electrical connectors
• Both atria contract together
• Both ventricles contract together

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Physiology of Circulation

• Synoatrial (SA) node pacemaker
• Located in right atrial wall near opening of
  superior VC.

• Impulse usually begins here, then spreads
  throughout atria causing atrial fibers to contract

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Physiology of Circulation

• Atrioventricular (AV) nodefound in right atrium
  along lower part of interatrial septum
• When the impulse reaches the AV node, it relays
  the message via the AV bundle

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Physiology of Circulation

• AV bundle (Bundle of HIS)originates in AV node
  and extends into interventricular septum,
  continues as the purkinje fibers.
• AV bundle together with the purkinje fibers cause
  ventricles to beat

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Physiology of Circulation

• Normally, the ventricular beat follows the atrial
  beathowever endocarditis, myocardial infarction
  or other infections can cause disruptions to this
  cycle.

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Electrocardiogram

• An ECG is a measurement of the electrical current
  in graphic formmade up of three main waves
• P Waveoccurs with depolarization of atria, its
  the electrical activity that triggers contraction
• QRS Waveoccurs during depolarization of the
  ventricles (masks the repolarization wave for
  atria)
• T Waveoccurs during repolarization of the
  ventriclesjust before the relaxation of the
  ventricles
• Damage to the cardiac muscle causes skewed ECG
  and will point to diagnosis and/or treatment.

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Electrocardiogram
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Blood pressure

• General Info
• Pressure of blood occurs in all blood vessels, it
  is higher in the arteries than the veins
• This pressure is necessary for circulationotherwi
  se blood wouldnt move.

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Blood pressure

• Factors influencing BP
• Blood volumethe higher the volume of blood in
  the arteries, the higher the pressure on the
  artery walls.
• Strength of heart contractionseach time the
  heart contracts, a certain volume of blood is
  released. The stronger the contraction, more
  blood sent higher pressure

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Blood pressure

• Factors cont
• Heart rateif the heat rate is up, it usually
  means the blood volume is downso instead of 70ml
  x 70 beats (4900 ml/min) you have 40ml x 100
  beats (4000ml/min) less blood pressure
• Blood viscositythinner blood will result in
  lower blood pressure
• Normal bp is 115/75

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PulsePoints
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Cardiovascular problems

• Hypertensionhigh blood pressure (anything
  consistently over 140/90)

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Cardiovascular problems

• Fibrillationrapid uncoordinated beating of heart
  muscle
• Tachycardiarapid heart rate (over 100
  beats/minute)
• Bradycardiaslow heart rate (less than 60
  beats/minute)

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Cardiovascular problems

• Congestive heart failureheart in such bad shape
  that circulation is totally inadequate to
  maintain body systems
• Angina pectorischest pain caused by lack of
  oxygen to heart
• Myocardial infarctionheart attackdeath of a
  part of the heart

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Cardiovascular problems

• Varicose veinsweak venous valvesgravity forces
  blood downward, causing stretching of the veins
  (particularly in lower leg)

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Cardiovascular problems

• Incompetent valveheart valve that isnt closing
  properly
• Murmurabnormal heart sounds caused by valve
  problems

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Cardiovascular problems

• Pericarditisinflammation of the pericardium
• Endocarditisinflammation of the endocardium.
  Endocarditis is abrasive to RBCs and can cause a
  clot.
• Thrombosisblood clot
• Coronary thrombosisblood clot in the coronary
  arteries

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Cardiovascular problems

• Cerebrovascular accidentstrokeresults from
  brain not receiving enough O2.
• Atherosclerosisdamming up of blood vessels
  causing blood flow problems

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Cardiovascular problems

• Angioplastyopening of blood vessels using small
  balloons and/or stents and not requiring surgery
• Cardiopulmonary Resuscitation (CPR)
• Procedure used to circulate blood in a person
  whose heart has stopped.