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.
© 2005 School of Nursing and Academic Division of Midwifery, University of Nottingham
Developer: Vivien Rolfe
Content author: Heather Bull
RLO released: 14th March, 2005
Page last updated: 29 March, 2021