THE HUMAN HEART

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THE HUMAN HEART
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OVERVIEW OF THE CARDIOVASCULAR SYSTEM

• Pulmonary circuit
• Systemic circuit
• Arteries (Including the coronary arteries)
• Veins (Including the coronary veins)
• Capillaries (Arterioles Venules)
• Four chambers of the heart

Pulmonary circuit
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HEART POSITIONING

• Located near the anterior chest wall
• Posterior to the sternum
• Lies slightly to the left of the midline
• Sits at an angle
• Rotated toward the left side

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Anatomical position of the heart from Grays
Anatomy
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Pericardial Cavity

• Anterior cavity of the mediastinum
• Separates the two pleural cavities
• Contains the thymus, esophagus the trachea

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Pericardium

• Pericardial cavity is lined by the pericardium.
• Visceral pericardium (epicardium) covers the
  hearts outer surface.
• Parietal pericardium lines the inner surface of
  the pericardial sac that surrounds the heart.
• Pericardial fluid acts as a lubricant reducing
  friction.

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The clear tissue being Lifted up by the scalpel
Is the pericardium
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Pericarditis

• Various pathogens may infect the pericardium.
• The inflamed pericardial surfaces rub against one
  another.
• Makes a distinct scratching sound.
• Cardiac tamponade could occur due to the
  increased pericardial fluid in the pericardial
  cavity. This condition restricts the movement of
  the heart.

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Black looking structure is the heart bulging from
the pericardial sac. Not only pathogens can
cause a cardiac tamponade, but blunt force trauma
can also cause it.
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Superficial Heart Anatomy

• When not filled with blood, the outer portion of
  each atrium deflates and becomes a lumpy,
  wrinkled flap.
• This extension is called the auricle (looks like
  an external ear).
• The coronary sulcus, marks the boundary between
  the atria and ventricles.

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Even though this is the posterior view of the
heart, the coronary sulcus goes around the
entire heart to separate the upper and lower
chambers.
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The anterior and posterior interventricular sulci
are shallower depressions that mark the boundary
line between the left and right
ventricles. These areas usually contain a large
amount of fat. The sulci contain the arteries and
veins that feed the heart. The heart has an
attached base and a free apex. The inferior tip
is called the apex. In a typical adult the heart
measures approximately 12.5 cm from the base to
the tip. The apex reaches to the fifth
intercostal space, 7.5 cm to the left of the
midline.
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Interventricular septum
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Superior Vena Cava. Brings blood from the head,
neck and shoulders to the right atrium
Interatrial septum
Inferior Vena Cava Brings blood back to the right
atrium from the rest of the body
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Interatrial Septum. Lateral view
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The pectinate muscles are prominent muscular
ridges found in the atrial walls
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Blood Flow

• Right atrium into the right ventricle via the
  right atrioventricular (AV) valve also called the
  tricuspid valve.
• The opening is bounded by three fibrous tissue
  cusps, therefore called the tricuspid valve.
• This tissue is braced by the tendinous chordae
  tendineae connected to papillary muscles

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Chordae tendineae
Papillary muscle
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Tricuspid Valve
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Right Heart

• Blood leaving the right ventricle enters the
  pulmonary trunk passing through the pulmonary
  semilunar valve.
• The pulmonary trunk divides into the left and
  right pulmonary arteries.
• These arteries are the only arteries in the body
  that carries oxygen poor blood.
• This blood is then carried to the lungs for
  re-oxygenation and removal of carbon dioxide.

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Remember you are looking at the right side of the
heart.
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5 are the pulmonary semilunar valve. 11 is the
pulmonary trunk.
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The left and right pulmonary returns the blood to
the left atrium. These are the only veins in the
body that carries oxygen rich blood. Blood will
then pass from the left atrioventricular valve
(AV) or also called the bicuspid or mitral
valve. From the left ventricle blood will then
pass through the aortic semilunar valve into the
ascending aorta into the systemic circulatory
system
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Pulmonary Veins
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8 is the aortic semilunar valve
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Ventricular Differences

• The anatomical differences between the right and
  left ventricles are as follows The right
  ventricle is relatively thin. The left ventricle
  has a massive muscular wall.

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Left Ventricle Heart Wall
Right Ventricle Heart Wall
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Atrioventricular Valves

• Prevent backflow of blood from the ventricles
  back into the atria.
• Chordae tendineae and papillary muscles play an
  important role in this process.
• Ventricular diastole the ventricles relax and the
  ventricles refill.
• The chorae tendineae are loose and offer no
  resistance to the flow of blood.

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During ventricular systole the ventricles begin
to contract blood moving back towards the atria
swings the cusps together closing the
valves. The chordae tendineae and papillary
muscles stops the cusps from swinging into the
atria. If those two structures are cut or
damaged the valves act as swinging doors, and
there is backflow, or regurgitation. Mitral
valve damage can especially occur in women after
pregnancy.
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The Heart Wall

• Bulk of the heart consists of the muscular
  myocardium and endocardium, that covers the inner
  surface of the heart.
• The epicardium is the visceral pericardium that
  covers the outer surface of the heart.

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• Cardiac muscle cells are interconnected by
  intercalated discs which convey the force of
  contraction from cell to cell and conduct action
  potentials.

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Heart Blood Supply

• Coronary circulation demands high oxygen and
  nutrients for the cardiac muscle cells.
• Coronary arteries originate at the base of the
  ascending aorta.
• Interconnections between arteries called
  anastomoses ensure a constant blood supply.

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Anastomoses
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Great, Posterior, small, Anterior, Middle
Cardiac Veins carry blood from The coronary
capillaries To the coronary sinus. Left coronary
artery supplies The left ventricle.
Circulflex Curves left meeting with The right
coronary artery. Left anterior decending Supplies
the posterior Decending artery (interventricular)
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