What is the structure, function, and location of the pleura, pericardium, and peritoneum?

What is the structure, function, and location of the pleura, pericardium, and peritoneum?

The pleura, pericardium and peritoneum are membranes that encapsulate major organs of the body. The pleura, the lungs, the pericardium the heart and the peritoneum the digestive organs. The pleura, pericardium and peritoneum are membranes that encapsulate major organs of the body.
The Pleura are membranes of the thoracic cavity. There are two pleura, the parietal and the visceral. The parietal pleura lines the inner surface of the thoracic cavity and ribcage. The visceral pleura line the lungs. The pleura secrete a fluid that fills the pleural space between the lungs and ribcage to reduce the friction created by the movement of the lungs during inhalation and exhalation.

The pericardium is a dense tissue sac that surrounds the heart. This membrane secretes fluid into the pericardial space between the heart and the pericardium. This fluid reduces the friction created by the movement of the heart during pumping the blood.

The peritoneum also consists of two types. The parietal peritoneum which lines the inner walls of the abdominal and pelvic cavities, while the visceral peritoneum lines the digestive organs. The peritoneal fluid helps lubricate the inner organs of the cavities, while the visceral peritoneum helps to support the organs.


What is the structure, function and location of pleura, peritoneum and pericardium?


These are the Layers that surround major organ of body.

What is Pleura?

That chest cavity is divided into median partition called mediastinum and laterally placed pleura and lungs.

Parts of Pleura:

Pleura has two parts;

1.Parietal Layer

2.Visceral Layer

Parietal Pleura

This layer covers the thoracic surface of diaphragm,lines the thoracic wall and occupy the lateral aspect of mediastinum.


It extends into the root of neck line,The under surface of suprapleural membrane at the thoracic outlet.

Visceral Pleura

It covers the outer surfaces of lung.


It extends into interlobar fissures of lung.

What is pulmonary Ligament?

For the movement of the pulmonary vessels and large bronchi during respiration the pleural cuff hangs down as a loose fold called the Pulmonary ligament.

What is Pleural cavity?

The parietal and visceral layers of pleura are separated from one another by a slitlike space,called Pleural cavity/Pleural space.

Pleural fluid:

The small amount of fluid in pleural cavity is called pleural fluid.It covers the surface of pleura as a thin film to allow movement between these two layers with the minimum of friction.

What is the regional distribution of Parietal pleura?

Cervical Pleura:

It extends upto the neck,lines the suprapleural membrane.It reaches upto the level 2.5 to 4cm above the medial third of clavicle.

Costal pleura:

It lines the inner surface of costal cartilages,ribs,intercostal spaces,back of the sternum and sides of vertebral bodies.

Diaphragmatic Pleura:

It covers the thoracic surface of diaphragm.

Mediastinal Pleura:

It covers and form the lateral boundary of mediastinum.At hilum of lungs,it is reflected as a cuff around the vessels and bronchi,here it continues with visceral pleura.It is seen,lungs lie free except at its hilum,which contain blood vessels and lymphatics.

What are the names of two recesses of Pleura?

1: Costodiaphragmatic recess

2: Costomediastinal recesses

Costodiaphragmatic recesses;

These are slit like spaces between costal and diaphragmatic parietal pleura,and are separated by capillary layer of pleural fluid.


During inspiration;the lower margins of lung descend into the recesses.

During expiration; the lower margins of lung ascend.In this way,both the costal and diaphragmatic pleura come together again.

Costomediastinal recesses;

These are the spaces between costal and mediastinal parietal layers of pleura,separated by a layer of pleural fluid.


During inspiration and expiration,anterior borders of lungs slide in and out of the recesses.

What is the nerve supply of Pleura?

The costal pleura is supplied by intercostal nerves.

The mediastinal pleura is supplied by phrenic nerves.

The diaphragmatic pleura is supplied by phrenic and lower six intercostal nerves.

What is pericardium?

Its a fibrous sac that enclose the heart and roots of great vessels.

Function of pericardium:

It restricts the excessive movements of heart as a whole and serve as a lubricated container,in which different parts of heart can contract.


It lies within the middle mediastinum,posterior to the body of sternum,extends from 2nd to 6th costal cartilages,lies anterior to 5th to 8th thoracic vertebrae.

What are the parts of pericardium?

Pericardium has two layers;

1.Fibrous pericardium

2.Serous pericardium

Fibrous pericardium;

Its a strong fibrous part of the sac.it fuses with outer coats of blood vessels,attached below to central tendons of diaphragm.

Vessels passing through it,are aorta,pulmonary trunk,pulmonary veins,superior and inferior vena cava.
It is attached in front of sternum.

Serous pericardium;

It lines the fibrous pericardium and surround the heart.

It has two layers;

1.Parietal layer

2.Visceral layer

Parietal layer;

It is continuous with the fibrous pericardium,reflected around the roots of great vessels to become continuous with visceral layer of serous pericardium.

Visceral layer;

It’s closely applied to the heart and often called ### **Epicardium.

What is pericardial Cavity?

The slit like space between Parietal and visceral layers is called pericardial cavity.

It contains a small amount of tissue fluid about 50ml, called pericardial fluid.

This fluid acts as lubricant for the movement of heart.

What is nerve supply of Pericardium?

It is supplied by phrenic nerves,vagus nerves and sympathetic trunks(Vasomotor).

What is peritoneum?

It is the abdominal membrane,that lies between abdomen and pelvic region of the body.It forms two layers, visceral and parietal layers,which form peritoneal cavity.

Functions of peritoneum;

•Visceral movement
•Visceral protection
•Fat storage
•Protection against infectious agents

It protects organs, e.g; stomach,liver,spleen,small and large intestine.

What is the blood supply of peritoneum?

It is supplied by;

•Superior epigastric artery

•Inferior epigastric artery

•Superficial circumflex iliac

•Superficial epigastric arteries.