Definition of periosteum in US English:



  • A dense layer of vascular connective tissue enveloping the bones except at the surfaces of the joints.

    • ‘The resultant cellulitis is preseptal, or anterior to the orbital septum, involving a fibrous layer beginning at the periosteum of the skull and extending to the eyelids.’
    • ‘The surgeon coagulates any superficial bleeding vessels with bipolar electrosurgery and uses a periosteal elevator to separate the periosteum from the bone.’
    • ‘Holes and channels run through it, carrying blood vessels and nerves from the periosteum, the bone's membrane covering, to its inner parts.’
    • ‘The orbital septum, a connective tissue reflection of the periosteum, inserts into the eyelids and separates them from the orbits.’
    • ‘Bone and periosteum are well innervated, and these nerve fibers transmit pain.’


Late 16th century: modern Latin, from Greek periosteon, from peri- ‘around’ + osteon ‘bone’.