Pleura and Lungs: Flashcards
Pulmonary cavity
Lined by serous membrane → pleural membrane
- Double layer – it is continuous at the level of the hilum
- Outer parietal pleura - lines pulmonary cavities
- Inner layer - visceral pleura, covers lung surface and extend
into fissures
- Layers continuous with each other around hilum of lung
Pleural cavity:
space between visceral and parietal pleura – contains serous fluid which prevents friction between lung and thoracic wall while breathing – also a potential space
Parietal pleura
Consists of different parts:
- Costal – lines inside of the ribcage
- Mediastinal – lines the media sternum (outside of pericardium)
- Diaphragmatic – on top of the diaphragm
- Cervical – part within the neck region
Endothoracic fascia (thin layer) Is deep to the pleural layer (thick and transparent) and suprapleural membrane is the top part of the endothoracic fascia
Pleural reflection lines
Relatively abrupt change in the direction of parietal pleura, it reflects from one wall of pleural cavity to another
- Sternal line – left and right
- Costal line – costal pleura becomes diaphragmatic pleura
- Vertebral line
Pleural cavity borders
Pleural cavity extends below inferior border of lungs.
Inf. Margin of pleura:
T12- at midline position
Midaxillary line
– Rib 10
Midclavicular line
– Rib 8
Xiphisternal joint at anterior midline
- Inferior border of lung is two ribs above pleural margin
- Anteriorly, lungs and pleural margin meet near xiphisternal joint
Pleural recesses
Pleural recesses
Lungs do not occupy pulmonary cavities completely during expiration
– potential pleural spaces
Costodiaphragmatic recess - Peripheral diaphragmatic pleura contact with lowermost costal pleura Costomediastinal recess - Posterior to sternum - Costal pleura meets mediastinal pleura
Blood supply
Parietal pleura:
- Intercostal (ant. And post.) arteries and veins
Blood supply
Visceral pleura: Same as lungs
- Bronchial arteries. (1 right and two left)
- Right bronchial vein → drains into v. azygos
- Left bronchial vein → drains accessory hemi - azygos or left sup.
intercostal vein - Pulmonary veins, two on each side
Each lung has:
Apex (above rib 1) • Base • Surfaces Costal Mediastinal Diaphragmatic • Borders Ant., inf. and post. • Lobes and fissures
R lung is shorter, wider, larger & heavier than L – Why?
Because heart is more towards left hand side, so less space for left lung to develop
Right lung:
Sup. lobe Middle lobe Inf. lobe Horizontal fissure Oblique fissure
Left lung
Sup. lobe
Inf. lobe
Oblique fissure
Lingula