1. Pleura of lung serous membrane that covers the lung parenchyma, mediastinum, diaphragm and the rib cage. It comprise visceral and parietal layer Pleural space :- Space between the two pleura of lung is known as pleural space Filled with pleural fluid. Pleural fluid reduced the friction between the two pleural membranes

2. Parietal Pleura It lines the thoracic wall. Covers the inner surface of rib cage, mediastinum and diaphragm. It extends into the root of neck to line the undersurface of suprapleural membrane at thoracic outlet lines:-Cervical pleura Costal pleura Diaphragmatic pleura Mediastinal pleura

3. Cervical pleura :-It extends from the superior thoracic aperture into the root of neck, forming a cup shaped pleural dome over the apex of lung. Diaphragmatic pleura:- Covers the superior or thoracic surface of diaphragm on each side of mediastium. Mediastinal pleura:-It covers the lateral aspects of the mediastinum. Costal pleura:-It covers the internal surface of Ribs Costal cartilages Intercostal spaces Sides of vertebral bodies Back of sternum

4. Visceral pleura Covers the lung. Cannot be dissected from lungs Insesitive to pain

5. Recesses of pleura :-Acts as a space or reserve space for lungs to expand during Deep inspiration. Two recess are formed:- Costomediastinal recesses Costodiaphragmatic recesses

6. Costomediastinal recesses :-slit like spaces between the costal and the mediastinal parietal pleura. Costodiaphragmatic recesses :- spaces between the costal and diaphragmatic parietal pleura.

7. Arterial supply Costal pleura : small branches of intercostal arteries Mediastinal pleura : supplied by pericardio phrenic artery Diaphragmatic pleura : supplied by superior phrenic and muscles Bronchial artery : supplies visceral pleura facing the mediastinum, pleura covering the interlobular surface and part of the diaphragmatic surface. Pulmonary artery : supplies remaining portion.

8. Venous drainage Through the intercostal veins which empty into inferior venacava or brachio-cephalic trunk. Nerve supply-Parietal pleura Sensitive to pain, temperature, touch and pressure. Costal pleura : innervated by segmental intercostal nerves. PERIPHERAL diaphragmatic pleura : innervated by lower 6 intercostal nerves. Central portion of diaphragmatic pleura and mediastinal pleura :-innervated by phrenic nerve.

9. Nerve supply-VISCERAL PLEURA Insensitive to common sensation such as pain and touch Innervated by autonomic nerves from the spinal segments T4 and T5. Pleural effusion Pleural effusion is excess fluid that accumulates between the two pleural layers, the fluid-filled space that surrounds the lungs.

10. Thoracocentesis procedure to remove fluid from the space between the lining of the outside of the lungs (pleura) and the wall of the chest.