Chapter 7 - Pericardium and Heart Flashcards
Features of fibrous pericardium
- Made of fibrous tissue
- Parietal layer of serous pericardium is attached to its deep surface
- Blunt apex at level of sternal angle
- Fused with roots of great vessels and pretracheal fascia
- Broad base blended with central tendon of diaphragm
- Connected to body of sternum by superior and inferior sternopericardial ligaments
- Posteriorly, related to principal bronchi, oesophagus, and descending thoracic aorta
- On sides, medistinal surface of lungs, phrenic N, pericardiacophrenic vessels
- Protects the heart from sudden overfilling and prevents overexpansion
Features of serous pericardium
- Double layered
- Inner layer is fused with heart except along cardiac grooves
- Parietal and visceral layers are continuous with each other at roots of great vessels
- Space between parietal and visceral is called pericardial cavity
- Pericardial cavity is filled with fluid for lubrication
Transverse sinus
-Horizontal gap between arterial and venous ends
A: Ascending aorta, pulmonary trunk
P: Superior vena cava
I: Left atrium
-Develops from degenration of central part of dorsal mesocardium
Oblique sinus
A: Left atrium P: Parietal pericardium, oesophagus Sides: Reflections of pericardium -Opens into pericardial cavity below -Permits free pulsation of left atrium -Develops due to rearrangement of veins in venous end
Contents of pericardium
- Heart
- Cardiac vessels and N
- Ascending aorta
- Pulmonary trunk
- Lower part of superior vena cava
- Inferior vena cava
- Pulmonary V
Blood supply of pericardium
- Internal thoracic A
- Musculophrenic A
- Descending thoracic aorta
Nerve supply of pericardium
- Fibrous and parietal: Phrenic N, sensitive to pain
- Visceral: autonomic N, no pain
- Pain of pericarditis: from parietal pericardium
- Pain of angina: Cardiac muscles, vessels
Pericardial effusion
- Cardiac tamponade
- Collection of fluid in pericardal cavity
- Restriction of venous filling is seen
- Cardiac output decreases
- Drained at 5th/6th intercostal space just lateral to sternum
Mitral stenosis
Left atrium enlarges
Compresses oesophagus
Dysphagia
Coronary sulcus
- Atrioventricular sulcus
- Right half of anterior part lodges right coronary A
- Left half lodges circumflex branch of left coronary A
- Overlapped anteriorly by ascending aorta and pulmonary trunk
Interventricular groove
ANTERIOR -nearer to left margin -runs downwards and left POSTERIOR -on inferior/diaphragmatic surface -nearer to right margin
Apex of heart
- Formed entirely by left ventricle
- Directed downwards, forward, to left
- Overlapped by anterior border of lung
- At 5th intercostal space
Base of heart
- Also called posterior surface
- Mainly left atrium
- Openings of 4 pulmonary veins and vena cavae
- Related to T5-T8
- Separated from vertebral column by pericardium, pulmonary V, oesophagus and aorta
Borders of the heart
Upper: Oblique, mainly by left atrium
Right: Vertical, right atrium, from SVC to IVC
Inferior: Horizontal, mainly right ventricle, IVC to apex
Left: Oblique and curved, mainly left ventricle, apex to left auricle
Sternocostal surface
- Formed mainly by right atrium and ventricle
- Mostly covered by lungs except at cardiac notch
- Uncovered part is dull in percussion–area of superficial cardiac dullness