Pulmonary pleura
Encyclopedia
Each lung
is invested by an exceedingly delicate serous membrane, the pleura, which is arranged in the form of a closed invaginated sac. A portion of the serous membrane covers the surface of the lung
and dips into the fissures between its lobes; it is called the pulmonary pleura (or visceral pleura).
The visceral pleura is attached directly to the lungs, as opposed to the parietal pleura, which is attached to the opposing thoracic cavity. The space between these two delicate membranes is known as the intrapleural space (pleural cavity). Contraction of the diaphragm causes a negative pressure within this space and forces the lungs to expand, resulting in passive inhalation. This process can be made forceful through the contraction of the external intercostal muscles, forcing the rib cage to expand and aiding to the negative pressure within the intrapleural space, which causes the lungs to fill with air.
Lung
The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...
is invested by an exceedingly delicate serous membrane, the pleura, which is arranged in the form of a closed invaginated sac. A portion of the serous membrane covers the surface of the lung
Lung
The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...
and dips into the fissures between its lobes; it is called the pulmonary pleura (or visceral pleura).
The visceral pleura is attached directly to the lungs, as opposed to the parietal pleura, which is attached to the opposing thoracic cavity. The space between these two delicate membranes is known as the intrapleural space (pleural cavity). Contraction of the diaphragm causes a negative pressure within this space and forces the lungs to expand, resulting in passive inhalation. This process can be made forceful through the contraction of the external intercostal muscles, forcing the rib cage to expand and aiding to the negative pressure within the intrapleural space, which causes the lungs to fill with air.