What is the pericardium and what are its main functions?

The pericardium is a fibroserous sac that encloses the heart and the roots of its great vessels. Its key functions include restricting excessive cardiac movement, providing a lubricated surface for contraction, and preventing cardiac overdistension.

What are the layers of the pericardium?

The pericardium consists of two main layers: the fibrous pericardium, an outer tough protective sac, and the serous pericardium, a double-layered membrane. The serous pericardium is further divided into the parietal layer lining the fibrous pericardium and the visceral layer covering the heart surface.

What is the pericardial cavity and what does it contain?

The pericardial cavity is a potential space between the parietal and visceral layers of the serous pericardium. It normally contains about 50 ml of serous fluid for lubrication and houses structures like the heart, ascending aorta, pulmonary trunk, and parts of the great veins.

What are the sinuses of the pericardium and why are they important?

The pericardium has two main sinuses formed by reflections of the serous pericardium: the transverse sinus (behind the ascending aorta and pulmonary trunk) and the oblique sinus (behind the left atrium). These sinuses are surgically relevant, with the transverse sinus used for vessel control during cardiac surgery.

How is the pericardium supplied by nerves and blood vessels?

Nerve supply includes the phrenic nerve (for fibrous and parietal layers, pain-sensitive) and autonomic nerves (for visceral layer, pain-insensitive). Arterial supply involves branches like the internal thoracic and coronary arteries, with the visceral layer supplied by coronary arteries.

What are some common clinical conditions involving the pericardium?

Common conditions include cardiac tamponade (fluid compression of the heart), pericarditis (inflammation with pain from the parietal layer), and pericardial friction rub (from inflamed surfaces). Procedures like pericardiocentesis are used to drain excess fluid.

Where is the pericardium located anatomically?

The pericardium is situated in the middle mediastinum, positioned behind the sternum and 2nd–6th costal cartilages, and in front of the T5–T8 vertebrae.

Pericardium – Layers, Cavity & Sinuses Explained

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