The pleura consists of two layers - the parietal pleura which lines the thoracic wall and diaphragm, and the visceral pleura which covers the lungs. Between these two layers is a potential space called the pleural cavity, which contains pleural fluid that lubricates the pleural surfaces and allows the lungs to slide smoothly against the chest wall during respiration. The pleura has several recesses that allow for full expansion of the lungs during deep inspiration.

1. Pleura

3. Pleura
Each lung is enclosed in a serous pleural sac
Serous membrane lined by flattened epithelium
(mesothelium)
Outer layer- Parietal pleura
Inner layer- Visceral pleura (Pulmonary pleura)
Pleural cavity: potential space in between two
layers
consists of serous pleural fluid, which lubricate
pleural surfaces

6. visceral pleura
• Pulmonary pleura
• Adherent to all surfaces including those in fissures
• Except the root or hilum of the lung
• Visceral pleura is continuous with parietal pleura at
the hilum of the lung

10. Parietal pleura
• Outer layer of the pleura
• Lines the corresponding half of the thoracic wall,
mediastinum and diaphragm
• It is divided into four parts

11. • Cervical pleura: lies over the apex of the lungs
• Costal pleura: covers the internal surface of
the thoracic wall
• Mediastinal pleura: covers the lateral aspect
of the mediastinum
• Diaphragmatic pleura: lies on the thoracic
surface of the diaphragm

13. Cervical pleura
• Dome of pleura,
• Covers the apex of the lungs
• Ascends from inner border of first rib to the
apex of the lung
• And then passes downwards on to the
mediastinal surface to become continuous
with mediastinal pleura

14. • Extends 3 -4 cm above the first costal cartilage
• 2.5 cm above the sternal end of the clavicle
• Cervical pleura is covered externally by supra pleural
membrane [ sibson fascia]
• Attaches to the internal border of first rib below and
transverse process of 7th cervical vertebra above
• Relation

15. • Relation
Anterior
Subclavian artery and scalenus anterior muscle.
Posterior
Neck of 1st rib and structures passing in front of it.
Lateral
Sclenus medius muscle
Medially
Great vessels of the neck

16. Costal pleura
• Lines the inner surface of the thoracic wall
(consisting of ribs, costal cartilage and
intercostal muscles )
• Separated from the above structures by
endothoracic fascia

18. Mediastinal pleura
• Covers the mediastinal surface of the lung.
• At the root of the lung it continous with viseral
pleura.
• Pulmonary ligament is downward continuation
of the parietal pleura and has two layer.

21. Diaphragmatic pleura
• Covers the superior surface of the diaphragm
• A thin elastic layer of endothoracic fascia
connects diaphragmatic pleura with muscular
part of diaphragm

24. Pleural receses
• Lungs do not occupy the pulmonary cavities
completely during expiration
• These gaps are the pleural recesses

25. Costodiaphragmatic recess
• Cleft like potential space between lower limit
of pleural sac and lower border of the
corresponding lung
• It makes a provision to allow the expansion of
the lung in full inspiration
• Most dependent part of pleural sac

29. Costomediastinal recess
• Between anterior border of the lung and
costomediastinal reflection of the pleura
• Left recess is larger because of cardiac notch

30. Nerve supply
• Costal and peripheral part of diaphragmatic
pleurae- intercostal nerves
• Mediastinal and central part of the
diaphragmatic pleurae- phrenic nerve
• Visceral pleura by autonomic nerve fibres
(through anterior and posterior pulmonary
plexuses)

31. Blood supply
• Arterial supply
• Parietal pleura- intercostal, internal thoracic
and musculophrenic arteries
• Visceral pleura- bronchial arteries
• Venous drainage
• Parietal pleura- azygous and internal thoracic
veins
• Visceral pleura- bronchial veins

32. Lymphatic drainage
Parietal pleura
• Intercostal lymph nodes
• Internal thoracic lymph node
• Posterior mediastinal lymph node
• Diaphragmatic lymph node.
• Visceral pleura
• Bronchomediastinal lymph node.

33. Pleurisy / pleuritis
• Commonly caused by tuberculosis.
• Inflammation of pleura- dry and wet
• Makes lung surfaces rough
• Pleural rub/ friction

34. Pneumothorax
• Accumulation of air in the pleural cavity
• Penetrating wounds Eg: bullet wound
• Tear of pleura by fractured rib

37. • Haemothorax
– Blood in the pleural cavity
• Hydropneumothorax
– Fluid with air in the pleural cavity
• Pleural effusion
–Escape of fluid into pleural cavity