The
pericardium (from the Greek περικάρδιον /perikardion/) is a double-walled sac that contains the
heartThe heart is a muscular organ found in all vertebrates that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
and the roots of the
great vesselsGreat vessels is a term used to refer collectively to the primary blood vessels, which include:*Vena cavae**Superior vena cava**Inferior vena cava*Pulmonary artery**Pulmonary trunk**Right pulmonary artery**Left pulmonary artery*Pulmonary veins...
.
There are two layers to the pericardial sac: the
fibrous pericardiumThe fibrous pericardium is the most superficial layer of the pericardium. It is a dense connective tissue, protecting the heart, anchoring it to the surrounding walls, and preventing it from overfilling with blood...
and the
serous pericardiumThe serous pericardium is deeper than the fibrous pericardium. It contains two layers, both of which function in lubricating the heart to prevent friction from occurring during heart activity:...
. The serous pericardium, in turn, is divided into two layers, the
parietal pericardium, which is fused to and inseparable from the fibrous pericardium, and the
visceral pericardium, which is part of the
epicardiumEpicardium describes the outer layer of heart tissue . When considered as a part of the pericardium, it is the inner layer, or visceral pericardium....
.
The
pericardium (from the Greek περικάρδιον /perikardion/) is a double-walled sac that contains the
heartThe heart is a muscular organ found in all vertebrates that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
and the roots of the
great vesselsGreat vessels is a term used to refer collectively to the primary blood vessels, which include:*Vena cavae**Superior vena cava**Inferior vena cava*Pulmonary artery**Pulmonary trunk**Right pulmonary artery**Left pulmonary artery*Pulmonary veins...
.
Layers
There are two layers to the pericardial sac: the
fibrous pericardiumThe fibrous pericardium is the most superficial layer of the pericardium. It is a dense connective tissue, protecting the heart, anchoring it to the surrounding walls, and preventing it from overfilling with blood...
and the
serous pericardiumThe serous pericardium is deeper than the fibrous pericardium. It contains two layers, both of which function in lubricating the heart to prevent friction from occurring during heart activity:...
. The serous pericardium, in turn, is divided into two layers, the
parietal pericardium, which is fused to and inseparable from the fibrous pericardium, and the
visceral pericardium, which is part of the
epicardiumEpicardium describes the outer layer of heart tissue . When considered as a part of the pericardium, it is the inner layer, or visceral pericardium....
. The epicardium is the layer immediately outside of the heart muscle proper (the myocardium).
In between the parietal and visceral pericardial layers there is a
potential spaceIn anatomy, potential space refers to a space or cavity that can exist because two adjacent features that are not tightly adjoined, but does not appear during normal functioning.-Examples:* subdural space* vagina* pericardial cavity...
called the
pericardial cavityThe pericardial cavity is a potential space between the parietal pericardium and visceral layer. It contains a supply of serous fluid. The serous fluid that is found in this space is known as the pericardial fluid....
. It is normally lubricated by a film of pericardial fluid. Too much fluid in the cavity (such as in a
pericardial effusionPericardial effusion is an abnormal accumulation of fluid in the pericardial cavity. Because of the limited amount of space in the pericardial cavity, fluid accumulation will lead to an increased intrapericardial pressure and this can negatively affect heart function...
) can result in pericardial tamponade (compression of the heart within the pericardial sac). A pericardectomy is sometimes needed in these cases.
Diseases/Abnormalities
- Pericarditis
Pericarditis is an inflammation of the pericardium .-Classification:Pericarditis can be classified according to the composition of the inflammatory exudate.Types include:* serous* purulent* fibrinous...
resulting in pericardial friction rubA pericardial friction rub, also pericardial rub, is an audible medical sign used in the diagnosis of pericarditis. Upon auscultation, this sign is an extra heart sound of to-and-fro character, typically with three components, one systolic and two diastolic. It resembles the sound of squeaky...
- Pericardial effusion
Pericardial effusion is an abnormal accumulation of fluid in the pericardial cavity. Because of the limited amount of space in the pericardial cavity, fluid accumulation will lead to an increased intrapericardial pressure and this can negatively affect heart function...
which may lead to cardiac tamponadeCardiac tamponade, also known as pericardial tamponade, is an emergency condition in which fluid accumulates in the pericardium . If the fluid significantly elevates the pressure on the heart it will prevent the heart's ventricles from filling properly. This in turn leads to a low stroke volume...
.
Religious Symbolism
The 10th century CE Islamic mystic Hallaj described God as He "who flows between the pericardium and the heart, just as the tears flow from the eyelids."
External links
- "Mediastinum: Pericardium (pericardial sac)"