Circulatory System

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Circulatory System

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Circulatory System

• Major Role The main role of the circulatory
  system is to transport nutrients, gases (such as
  oxygen and CO2), hormones and wastes through the
  body.  
• Major Organs Heart, blood vessels and blood.

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Anatomy of the Circulatory System

• The Main Features
• Two pumps (in a single heart)
• one to pump deoxygenated blood to the lungs
• the other to pump oxygenated blood to all the
  other organs and tissues of the body.
• A system of blood vessels to distribute blood
  throughout the body
• Specialized organs for exchange of materials
  between the blood and the external environment
  for example
• organs like the lungs and intestine that add
  materials to the blood and
• organs like the lungs and kidneys that remove
  materials from the blood and deposit them back in
  the external environment.

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Circulatory System

• Red blood cells carry oxygen from the lungs to
  all the cells of the body.
• White blood cells are like soldiers protecting
  the body.
• ARTERIES are vessels that carry blood away from
  the heart.
• VEINS are vessels that carry blood back to the
  heart.
• Blood CIRCULATES--circles--all around your body
  in about one or two minutes. 5 liters
• Inside the heart are four hollow chambers. Each
  chamber is a little pump. The pumping pushes
  blood all around your body.

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Circulatory System

• It's small, a little larger than a clenched fist.
  Relatively simple in function, your heart's
  primary purpose is to pump...24 hours a day, 70
  to 80 times a minute. With each beat, the heart
  pumps blood that delivers life-sustaining oxygen
  and nutrients to 300 trillion cells. Each day the
  average heart "beats" (or expands and contracts)
  100,000 times and pumps about 2,000 gallons of
  blood. In a 70-year lifetime, an average human
  heart beats more than 2.5 billion times, pumping
  approximately 55 million gallons of blood.

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Anatomy of the Circulatory System

• The Coronary System
• From the left atrium,
• Blood flows through the mitral valve (also known
  as the bicuspid valve) into the left ventricle.
• Contraction of the ventricle closes the mitral
  valve and opens the aortic valve at the entrance
  to the aorta.
• The first branches from the aorta occur just
  beyond the aortic valve still within the heart.
• Two openings lead to the right and left coronary
  arteries, which supply blood to the heart itself.
  Although the coronary arteries arise within the
  heart, they pass directly out to the surface of
  the heart and extend down across it. They supply
  blood to the network of capillaries that
  penetrate every portion of the heart.
• The capillaries drain into two coronary veins
  that empty into the right atrium.

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Anatomy of the Circulatory System

• Deoxygenated blood from the body enters the right
  atrium.
• It flows through the tricuspid valve into the
  right ventricle. The term tricuspid refers to the
  three flaps of tissue that make up the valve.
• Contraction of the ventricle then closes the
  tricuspid valve and forces open the pulmonary
  valve.

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Anatomy of the Circulatory System

• Blood flows into the pulmonary artery.
• This branches immediately, carrying blood to the
  right and left lungs.
• Here the blood gives up carbon dioxide and takes
  on a fresh supply of oxygen.
• The capillary beds of the lungs are drained by
  venules that are the tributaries of the pulmonary
  veins.
• Four pulmonary veins, two draining each lung,
  carry oxygenated blood to the left atrium of the
  heart

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How The Heart Beats

• Have you ever wondered what makes your heart
  beat? How does it do it automatically, every
  second of every minute of every hour of every
  day?
• The answer lies in a special group of cells that
  have the ability to generate electrical activity
  on their own.

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How The Heart Beats

• The natural pacemaker of the heart is called the
  sinoatrial node (SA node). It is located in the
  right atrium.
• The electrical impulse leaves the SA node and
  travels to the right and left atria, causing them
  to contract together. This takes seconds.

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How The Heart Beats

• There is now a natural delay to allow the atria
  to contract and the ventricles to fill up with
  blood.
• The electrical impulse has now traveled to the
  atrioventricular node (AV node)

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How The Heart Beats

• The electrical impulse now goes to the Bundle of
  His (3), then it divides into the right and left
  bundle branches (4) where it rapidly spreads
  using Purkinje fibers (5) to the muscles of the
  right and left ventricle, causing them to
  contract at the same time.

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EKG

• All this activity produces electrical waves we
  can measure. The measurement is typically
  represented as a graph called an
  electrocardiogram (EKG).
• Each part of the tracing has a lettered name
• P wave - coincides with the spread of electrical
  activity over the atria and the beginning of its
  contraction.
• QRS complex - coincides with the spread of
  electrical activity over the ventricles and the
  beginning of its contraction.
• T wave - coincides with the recovery phase of the
  ventricles.

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Circulatory System Disease

• The single major cause of artery disease is the
  thickening and hardening of arterial walls by
  deposits of fatty materials, known as
  arteriosclerosis.

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Circulatory System Disease

• Arteriosclerosis
• The coronary arteries arise at the point of
  maximum blood pressure in the circulatory system.
  Over the course of time, the arterial walls are
  apt to lose elasticity, which limits the amount
  of blood that can surge through them and hence
  limits the supply of oxygen to the heart. This
  condition is known as arteriosclerosis.
• Atherosclerosis
• Fatty deposits, called plaque, may accumulate on
  the interior surface of the coronary arteries.
  This is particularly common in people who have
  high levels of cholesterol in their blood. Plaque
  deposits reduce the bore of the coronary arteries
  and thus the amount of blood they can carry.
• Atherosclerosis (usually along with
  arteriosclerosis) may
• so limit the blood supply to the heart that
  during times of stress the heart muscle is so
  deprived of oxygen that the pain of angina is
  created.
• trigger the formation of a clot causing a
  coronary thrombosis. This stops the flow of blood
  through the vessel and the capillary network it
  supplies causing a heart attack. The portion of
  the heart muscle deprived of oxygen dies quickly
  of oxygen starvation. If the area is not too
  large, the undamaged part of the heart can, in
  time, compensate for the damage.
• Coronary bypass surgery uses segments of leg
  veins to bypass the clogged portions of the
  coronary arteries.

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Arteriosclerosis

• Vascular disease, which affects the brain, heart,
  kidneys, other vital organs, and extremities, is
  the leading cause of morbidity and mortality in
  the USA and in most Western countries.
• There were almost 1 million deaths due to
  vascular disease in the USA in 1994 (twice as
  many as from cancer and 10 times as many as from
  accidents).
• CAD and ischemic stroke combined are the number
  one killer in industrialized Western countries
  and are of increasing prevalence in the rest of
  the world.
• The death rate from CAD among white men aged 25
  to 34 is about 1/10,000 at age 55 to 64, it is
  nearly 1/100.
• The death rate from CAD among white men aged 35
  to 44 is 6.1 times that among age-matched white
  women.

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Arteriosclerosis

• Atherosclerosis is a disease of the arteries in
  which fatty material is deposited in the vessel
  wall, resulting in narrowing and eventual
  impairment of blood flow. Severely restricted
  blood flow in the arteries to the heart muscle
  leads to symptoms such as chest pain.
  Atherosclerosis shows no symptoms until a
  complication occurs.

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Arteriosclerosis
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Carotid Stenosis

• Carotid artery stenosis is the narrowing of the
  carotid arteries. These are the main arteries in
  the neck that supply blood to the brain.
• This is an angiogram of the right carotid artery
  showing a severe narrowing (stenosis) of the
  internal carotid artery just past the carotid
  fork. There is enlargement of the vein or
  ulceration in the area after the stenosis in this
  close-up film. Note the narrowed segment toward
  the bottom of the picture.

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Angina

• Angina is chest pain or discomfort that occurs
  when your heart muscle does not get enough blood.
  Angina may feel like pressure or a squeezing pain
  in your chest. The pain may also occur in your
  shoulders, arms, neck, jaw, or back. It may also
  feel like indigestion.
• Stable angina and Unstable
• Nitroglycerin is the most commonly used nitrate
  for angina. Nitroglycerin that dissolves under
  your tongue or between your cheeks and gum is
  used to relieve an angina episode. Nitroglycerin
  in the form of pills and skin patches is used to
  prevent attacks of angina. (Nitroglycerin in
  these forms acts too slowly to relieve pain
  during an angina attack.)

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Coronary artery balloon angioplasty
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Coronary artery balloon angioplasty

• Fat and cholesterol accumulates on the inside of
  arteries (atherosclerosis). The small arteries of
  the heart muscle (the coronary arteries) can be
  narrowed or blocked by this accumulation. If the
  narrowing is small, percutaneous transluminal
  coronary angioplasty, or PTCA for short, may be
  the course for treatment. PCTA is a minimally
  invasive procedure to open up blocked coronary
  arteries, allowing blood to circulate
  unobstructed to the heart muscle.
• The indications for PCTA are
• persistent chest pain (angina)
• blockage of only one or two coronary arteries

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Coronary artery balloon angioplasty

• The patient is awake and pain-free (local
  anesthesia), a catheter is inserted into an
  artery at the top of the leg (the femoral
  artery). The procedure begins with the doctor
  injecting some local anesthesia into the groin
  area and putting a needle into the femoral artery
  (the blood vessel that runs from the heart down
  the leg). Once the needle is inserted, a guide
  wire is placed through the needle, into the blood
  vessel. Following this step, the guide wire is
  left in the blood vessel and the needle is
  removed. A large needle called an introducer is
  then placed over the guide wire and the guide
  wire is removed.

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Coronary artery balloon angioplasty

• Next, a diagnostic catheter, which is a long
  narrow tube, is advanced through the introducer
  over a .035"guidewire, into the blood vessel.
  This catheter is then guided to the aorta and the
  guidewire is removed. Once the catheter is placed
  in the opening or ostium of one of the coronary
  arteries, the doctor injects dye and takes a
  series of X-rays (film of the images).

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Coronary artery balloon angioplasty

• The first catheter is exchanged out over the
  guidewire for a guiding catheter and the
  guidewire is removed. A smaller guidewire is
  advanced across the blocked section of the
  coronary artery and a balloon -tipped tube is
  positioned so the balloon part of the tube is
  beside the blockage. The balloon is then inflated
  for a few seconds to compress the blockage
  against the artery wall. Then the balloon is
  deflated. The doctor may repeat this a few times,
  each time pumping up the balloon a little more to
  widen the passage for the blood to flow through.
  This treatment may be repeated at each blocked
  site in the coronary arteries.

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Coronary artery balloon angioplasty

• A device called a stent may be placed. A stent is
  a latticed, metal scaffold that is placed within
  the coronary artery to keep the vessel open.

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Coronary artery balloon angioplasty

• Once the catheter has been positioned at the
  coronary artery origin, contrast media is
  injected and a series of X-rays (film) are taken
  to check for any change in the arteries.
  Following this, the catheter is removed and the
  procedure is completed.

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Coronary Bypass Surgery
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Thrombophlebitis

• Deep venous thrombosis (DVT) affects mainly the
  veins in the lower leg and the thigh. It involves
  the formation of a clot (thrombus) in the larger
  veins of the area.

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Thrombophlebitis

• This picture shows a red and swollen thigh and
  leg caused by a blood clot (thrombus) in the deep
  veins in the groin (ileofemoral veins) which
  prevents normal return of blood from the leg to
  the heart.

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Circulatory System-Alveoli
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Circulatory System-Alveoli
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Circulatory System-Alveoli
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Pulmonary Disease

• Chronic obstructive pulmonary disease (COPD) is a
  term used to describe 2 related lung diseases
  chronic bronchitis and emphysema.
• Chronic bronchitis is inflammation and eventual
  scarring of the bronchi (airway tubes).
• Emphysema is enlargement and destruction of the
  alveoli (air sacs) within the lungs. Many persons
  with COPD have both of these conditions.
• Persons with COPD have difficulty breathing
  because they develop smaller air passageways and
  have partially destroyed alveoli. The air
  passageways also become clogged with mucus, a
  slimy substance. Smoking cigarettes is the most
  important risk factor and cause of COPD. About
  80 to 90 of COPD cases are caused by smoking,
  and a smoker is 10 times more likely than a
  nonsmoker to die of COPD.

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Pulmonary Disease

• Most of the medications fall into one of three
  groups
• Bronchodilators (beta agonists anticholinergics
  theophylline)
• Anti-inflammatories (inhaled corticosteroids
  long-acting beta agonists corticosteroid pills)
• Quick Relief Medications
• Long Term Control Medications
• Antibiotics