RLO: Ventilation

School of Nursing and Academic Division of Midwifery

Anatomy of ventilation (at rest)

The external intercostal muscles are strips of skeletal muscle that lie at an oblique angle between adjacent ribs. When they contract they raise the ribs outwards.

The diaphragm, intercostal muscles and the rib-cage are fully-lined inside by a fluid-secreting membrane called the parietal pleura. Together these structures make up the walls of the thorax which encase the lungs.

The lungs are covered by another fluid-secreting membrane called the visceral pleura. These two membranes lie side-by-side, very close together and are collectively called the pleural membrane. They secrete a thin film of serous fluid into the cavity between them. This closed, fluid-filled space is called the pleural cavity.