PLEURAE and PLEURAL RECESSES

Transcription

1 PLEURAE and PLEURAL RECESSES By Dr Farooq Aman Ullah Khan PMC 26 th April 2018

2 Introduction When sectioned transversely, it is apparent that the thoracic cavity is kidney shaped: a transversely ovoid space deeply indented posteriorly by the thoracic vertebral column. The thoracic cavity is divided into three compartments: Right and left pulmonary cavities. A central Mediastinum.

3 PLEURAL SAC Each lung is invested by a delicate serous membrane, the pleura, which is arranged in the form of a closed invaginated sac. OR The pleura-lined the cavity which contains the lung and it lie on either sides of the mediastinum within the chest cavity.

4 pleural SAC.Con T It is lined single layer of flat cells, Mesothelium and an associated layer of supporting connective tissue. Extensions Superiorly. It extend above rib 1, into the root of the neck. Inferiorly. It extend to the level just above the costal margin. Medially. The mediastinum.

5 Parts of PLEURA. Each pleura has two parts: 1.A parietal layer of pleura forms its external wall. 2. A visceral layer the internal wall that invests the lungs.

6 Visceral Pleura The visceral pleura is a delicate serous membrane that closely covers the surfaces of the lungs and dips into the fissures that separate the lobes. In cadaver dissections it can not be usually dissected from the surface of the lung. It provides the lung with a smooth slippery surface, enabling it to move freely on the parietal pleura. It is continuous with the parietal pleura at the root/hilum of the lung, where structures enter and leave it.

7 Parietal pleura This is the external wall of the pleural cavity and is adherent to the thoracic wall and diaphragm by connective tissue. The parietal pleura is also attached to the pericardium. It is thicker then the visceral pleura.

8 parietal pleura Con T The parietal pleura is given different names according to the parts with which it is associated: 1. Costal pleura (ribs and sternum) 2. Mediastinal pleura (mediastinum) 3. Diaphragmatic pleura (diaphragm) 4. Cervical pleural (superapleural membrane).

9 Cervical pleura: Extends up into the neck lining the undersurface of the suprapleural membrane.(dome of pleura or pleural cupola). It is the upward continuation of the mediastinal and costal parts. Diaphragmatic pleura: Covers the thoracic surface of the diaphragm. A thin, more elastic layer of the endothoracic fascia (the phernicopleural fascia), connects the diaphragmatic pleura with the muscular fibers of the diaphragm.. parietal pleura Con T

10 Costal pleura: It lines the inner surface of the ribs, costal cartilages,intercostals spaces, sides of the vertebral bodies and the back of the sternum. It is separated from the internal surface of the thoracic wall by endothoracic fascia. parietal pleura Con T Mediastinal pleura: It covers and forms the lateral boundary of mediastinum. At the hilum of the lung it reflects to become continuous with the visceral pleura.

11 PLEURAL CAVITY The two layers of pleura are separated from each other by a slit like space called pleural cavity The pleural cavity also contains pleural fluid, which allows the pleurae to slide effortlessly against each other during ventilation

12 Endothoracic fascia The endothoracic fascia is the layer of loose connective tissue deep to the intercostal spaces and ribs, separating these structures from the underlying pleura. This fascial layer is the outermost membrane of the thoracic cavity. The endothoracic fascia contains variable amounts of fat. It becomes more fibrous over the apices of the lungs as the suprapleural membrane. It separates the internal thoracic artery from pleura.

13 Suprapleural Membrane Thickening of connective tissue that covers the apex of lung. Extension of endothoracic fascia that exists between parietal pleura and thoracic cage. It extends between the inner border of first rib and transverse process of C7 vertebra. It act as a rigid barrier so as to prevent changes in intrathoracic pressure upon the contents of the neck.

14 PULMONARY LIGAMENT The parietal pleura surrounding the root of the lung extends downwards beyond the root as a fold called the pulmonary ligament. The fold contains a thin layer of loose areolar tissue with a few lymphatic's. Actually it provides a dead space into which the pulmonary veins can expand during increased venous return as in exercise. The lung roots can also descend into it with the descend of the diaphragm.

15 PLEURAL RECESSES. The spaces where the different portions of the pleura join at an angle and which are never completely filled by lung tissue. These are: 1. Costodiaphragmatic recess. 2. Costomediastinal recess.

16 Costodiaphragmatic Recesses These are slit-like intervals between the costal and diaphragmatic pleurae on each side. They become alternatively smaller and larger as the lungs move in and out of them during inspiration and expiration. Pleural effusions collect in the Costodiaphragmatic recess when in standing position. The largest and clinically most important recesses.

17 CoSTodiAphRAgmATiC RECESSES..Con T

18 CoSTodiAphRAgmATiC RECESSES..Con T It is the lower most part of the pleural cavity. Vertically it measures 5 cm in length. It extend from rib 8 to 10, along Mid Axillary line. Costodiaphragmatic recesses

19 Costo-mediastinal Recesses These are situated along the anterior margins of the pleura. They are slit-like spaces between the costal and mediastinal parietal pleura separated by a capillary layer of pleural fluid. During inspiration and expiration the anterior borders of the lungs slide in and out of the costomediastinal recess.

20 PARIETAL PLEURAL INNERVATION It is sensitive to pain, temperature, touch and pressure is supplied as follow. Supplied by somatic nerves. 1.Costal pleura It is segmentally supplied by intercostal nerves. Pain from these area would be felt in relation to the thoracic wall.

21 parietal pleural innervation..con T 2.Mediastinal pleura: It is supplied by the phrenic nerve Pain from these area would refer to neck and supraclavicular region of shoulder. 3.Diaphragmatic pleura: It is supplied over domes by phrenic and around the periphery by the lower six intercostal nerve.

22 VISCERAL PLEURA INNERVATION The visceral pleura is sensitive to stretch but is insensitive to pain and touch. It receives an autonomic nerve supply from pulmonary plexus. (T2 to T5)

23 Vascular Supply of PLEURA The arteries of the pleura are derived from the. Intercostal, Internal mammary, Musculophrenic, Pericardial, and Bronchial vessels. The veins correspond to the arteries.

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25 Lines of Pleural Reflection Lines that, usually projected onto the surface of the thoracic wall, indicating the abrupt change in direction of the parietal pleura as it passes from one wall of the pulmonary cavity to another. Three lines of pleural reflection outlines the extent of the pulmonary cavities. Sternal. Costal. Diaphragmatic They are asymmetrical.

26 Pleural Reflection Superiorly: Pleural cavity can project as much as 3-4 cm above the first costal cartilage.

27 pleural REfLECTion..Con T Anteriorly: Pleural cavities approach each other posterior to the upper part of the sternum. Posterior to the lower part of the sternum, the parietal pleura does not come as close to the midline on the left side.

28 pleural REfLECTion..Con T Inferiorly: In the midclavicular line, the pleural cavity extend inferiorly to rib VIII. In the midaxillary line, it extends to rib X. From this point, the inferior margin courses horizontally, to reach vertebra XII.

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32 Pleurisy Pleurisy, also known as pleuritis, is inflammation of the membranes (pleurae) that surround the lungs and line the chest cavity. This can result in a sharp chest pain with breathing. Occasionally the pain may be a constant dull ache. Other symptoms may include shortness of breath, cough, fever or weight loss, depending on the underlying cause e.g: viral, bacterial and environmental.

33 Pleural Aspiration

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36 pnemothorax.con T

37 t Thank You..