The PPP and OSI protocols share the same physical layer, but PPP distributes the functions of LCP and NCP differently. PPP operates across any DTE/DCE interface. The only requirement imposed by PPP is a duplex circuit, either dedicated or switched, that can operate in either
From Wikipedia, the free encyclopedia. The cisterna magna (or cerebellomedullary cistern) is one of three principal openings in the subarachnoid space between the arachnoid and pia mater layers of the meninges surrounding the brain. The openings are collectively referred to as cisterns.he two other principal cisterns are the pontine cistern located between the pons and the medulla, and the interpeduncular cistern located between the cerebral peduncles. Cerebral spinal fluid can also be obtained by puncture of the cisterna magna (cistern puncture).
Tarlov cysts (hereafter referred to as TCs) are also known as perineural/perineurial, or sacral nerve root cysts. They are dilations of the nerve root sheaths and are abnormal sacs filled with cerebrospinal fluid (hereafter referred to as CSF) that can cause a progressively painful radiculopathy (nerve pain).erineural cysts can form in any section of the spine; a significant percentage (11%) of patients have cysts at more than one location of the spine.. Some patients have cysts at all sections of the spine, including cervical, thoracic, lumbar, and sacral.