PERICARDIUM
• Pericardium
• Conical fibroserous sac
• Encloses heart and roots of great vessels
• Lies within middle mediastinum
• Apex Fused with outer adventitia of great vessels
• Base lies on central tendon of Diaphragm
• Lies behind the body of sternum and second –sixth costal cartilages
• Posteriorly, related – esophagus, descending
thoracic aorta, and bodies of 5th
to 8th
thoracic vertebrae
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Human Anatomy/Yogesh Sontakke
Functions of Pericardium
• Protection of heart (shock absorption)
• Restriction of excessive movements of heart
• Prevention of overexpansion of heart
• Prevents kinking of great blood vessels
• Minimizes friction between heart and surrounding
structures
• Mechanical barrier for spread of infection
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Human Anatomy/Yogesh Sontakke
Subdivisions of pericardium
Fibrous pericardium
• Outer layer of pericardium
• Single-layered, thick, and cone-shaped sac encloses heart and fuses with roots of major
vessels
Serous pericardium
• Inner double-layered blind sac of pericardium
• Two layers:
• Parietal layer: Lines inner surface of fibrous pericardium
• Visceral layer or epicardium: Lines outer surface of heart and great blood vessels
• Except at cardiac groove visceral layer is not attached to epicardium due to separation
by cardiac vessels
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FIBROUS PERICARDIUM
• Cone-shaped
• Thick sac of fibrous connective tissue
Features of Fibrous Pericardium
• Conical and has apex and base
• Apex – directed above and blends with external
coats of ascending aorta and pulmonary trunk
• Base – broad and fuses with central tendon of
diaphragm
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Features of Fibrous Pericardium
• Anteriorly – Connected with sternum by superior and inferior sternopericardial
ligaments
• Posteriorly – related – principal bronchi, esophagus, and descending thoracic aorta
• On each side – related – mediastinal pleura, phrenic nerves, and pericardiophrenic
vessels
• Protects and keeps heart in place
• Prevents over distension of heart and kinking of great vessels
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SEROUS PERICARDIUM
• Thin, double-layered serous sac lies within fibrous pericardium
• Lined by simple squamous epithelium called mesothelium
Layers of Serous Pericardium
Consists of two layers
Parietal layer
• Outer layer and lines inner surface of fibrous pericardium, blends with fibrous
pericardium
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Layers of Serous Pericardium
Visceral layer (epicardium)
• Inner layer, covers external surface of heart and root of great vessels
• Separated from heart (specially along cardiac grooves) by subserous areolar and fatty
tissue, and blood vessels
• Visceral layer – continuous with parietal layer along roots of great blood vessels
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PERICARDIAL CAVITY
•Potential space between parietal and visceral layers of serous
pericardium
•Normally, contains small amount of serous fluid (15–20ml)
•Pericardial fluid reduces friction within pericardium during
movements of heart by lubricating opposed surfaces of serous
pericardium
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CONTENTS OF PERICARDIUM
1. Heart with its vessels and nerves
2. Ascending aorta
3. Pulmonary trunk
4. Lower half of superior vena cava
5. Terminal part of inferior vena cava
6. Terminal part of pulmonary veins
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BLOOD SUPPLY
Blood Supply
•Fibrous and parietal layer of visceral pericardium
•Arterial supply: Branches of internal thoracic, musculophrenic
arteries, and descending thoracic aorta
•Venous drainage: Azygos and internal thoracic veins
•Visceral pericardium
•Arterial supply: Coronary arteries
•Venous drainage: Coronary sinus
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NERVE SUPPLY
As fibrous and parietal pericardium develop from somatopleuric mesoderm
•Supplied by phrenic (somatic) nerves and they pain sensitive
•As visceral pericardium develops from splanchnopleuric mesoderm
•Supplied by branches of sympathetic trunk and vagus nerve (autonomic
nerves)
•Insensitive – pain
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SINUSES OF PERICARDIUM
•Communicating zones –developed by
reflection of serous pericardium
•Two sinuses of pericardium
•Transverse sinus
•Oblique sinus
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Reason behind sinuses of pericardium
• Visceral pericardium forms two tubes around great vessels of heart as follows
• One arterial tube around embryonic arterial end of heart later forms ascending
aorta and pulmonary trunk
• Another venous tube around embryonic venous end of heart later forms superior
and inferior venae cavae and forms pulmonary veins
• Initially, arterial and venous ends connected by dorsal mesocardium
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Transverse Sinus
• Horizontal passage between anterior arterial end
and posterior venous end of heart
• Develops on degeneration of dorsal
mesocardium
Boundaries
• Anterior: Ascending aorta, pulmonary trunk
• Posterior: Superior vena cava
• Inferior: Left atrium
• Superior: Bifurcation of pulmonary trunk
• On each side: Opens into main pericardial cavity
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Oblique Sinus
•Cul-de-sac behind left atrium
•Recess of serous pericardium
enclosed by J-shaped sheath of
visceral pericardium –encloses six
veins
• Superior and inferior venae cavae
and four pulmonary veins
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Oblique Sinus
Development
•Oblique sinus develops due –
Absorption of pulmonary vein in
developing left atrium → formation
of 4 pulmonary veins
•Absorption of sinus venosus in
developing right atrium → separation
of SVC from IVC
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Oblique Sinus
Boundaries
• Anterior: Left atrium
• Posterior: Parietal pericardium
right: Two right pulmonary veins and inferior
vena cava
• On the left: Two left pulmonary veins
• Superior: Reflection of visceral pericardium
along right and left superior pulmonary veins
(along upper margin of left atrium)
• Inferior: Communicates with main pericardial
cavity
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Clinical Integration
• Significance of transverse pericardial sinus
• During cardiac surgery, temporary ligature may
be passed through transverse sinus to block blood
flow through aorta and pulmonary trunk
• Pericarditis: Inflammation of pericardium
• Pericardial friction rub
• In pericarditis, smooth opposing surfaces of
serous pericardium become rough
• Results in pericardial friction rub
• Can be heard as rustle of silk with use of
stethoscope
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Clinical Integration
•Pericardial effusion
•Accumulation of excessive fluid in
pericardial cavity
•Causes: Congestive heart failure,
pericarditis, tuberculosis, kidney
failure, heart surgery, and so on
•Symptoms of pericardial effusion
rises due – pressure on heart and
prevention of complete filling of
chamber of heart
•Includes chest pain
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Clinical Integration
• Pericardial effusion
• Pressure on heart and prevention of
complete filling of chamber of heart
• Water-bottle heart on chest radiograph
• Has enlarged cardiac shadow in form of
shape of flask or water bottle
• Cardiac tamponade
• Compression of heart – Due – inelastic
nature of tough fibrous pericardium
• Reduces filling of cardiac chambers during
diastole and thus reduces cardiac output
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Pericardiocentesis
•Aspiration of fluid from pericardium
•Position of patient
•Supine, head end of bed raised by
30°–60° to bring heart closer –
anterior chest wall
•Procedure
Can be done using two approaches
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Pericardiocentesis
Procedure
•Subxiphoid approach
•Needle inserted in left
costoxiphoid angle with upward
inclination of about 45° – skin
•Parasternal route
•Needle introduced into left 5th
or
6th
intercostal space – left sternal
border under ultrasound guidance
•Preferred elective procedure
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