The suprapleural membrane, eponymously known as Sibson's fascia, is a structure described in human

anatomy Anatomy () is the branch of biology concerned with the study of the structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having its ...

. It is named for Francis Sibson.

Anatomy

It refers to a thickening of

connective tissue Connective tissue is one of the four primary types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesenchyme derived from the mesoderm the middle embryonic germ layer. Connective tissue ...

that covers the apex of each human lung. It is an extension of the endothoracic fascia that exists between the parietal pleura and the thoracic cage. Sibson muscular part is originated from scalenus medius muscle. Fascial part is originated from Endothoracic Fascia. It attaches to the internal border of the first rib and the transverse processes of

vertebra The spinal column, a defining synapomorphy shared by nearly all vertebrates, Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characterist ...

C7. It extends approximately an inch more superiorly than the superior thoracic aperture, because the lungs themselves extend higher than the top of the ribcage.

Clinical significance

*The function of the suprapleural membrane is to protect the apex of the lung (as some of the part which extends outside the rib cage) and to protect the cervical fascia. This helps in resisting intrathoracic pressure changes therefore preventing inflation and deflation of the neck during expiration and inspiration respectively and also providing rigidity to the thoracic inlet. *Herniation of the cervical fascia may result due to injury to suprapleural membrane. **"The thoracic duct traverses Sibson's Fascia of the thoracic-inlet up to the level of C7 before turning around and emptying into the left (major) duct. The right (minor duct) only traverses the thoracic inlet once."p. 86, p 210, Kuchera, WA.

References

Thoracic cavity Pleura {{anatomy-stub