A course of dissections, for the use of students / [Herbert Mayo].

  • Mayo, Herbert, 1796-1852
Date:
1827
Catalogue details

Licence: Public Domain Mark

Credit: A course of dissections, for the use of students / [Herbert Mayo]. Source: Wellcome Collection.

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    the fourth sinus, or torcular Herophili. A small, sinus may be seen creeping backward in the dura mater on the pars petrosa to join the lateral sinus: it is called the superior petrous sinus. The circular sinus is disposed around the sella tur¬ cica, and opens into the cavernous sinus, which is con¬ tained in a reflection of the dura mater from the edge of the sella turcica to the greater ala of the sphenoid bone; and this again communicates with the lateral sinus near its termination, by means of the inferior pe¬ trous sinus, which passes downward in a groove at the edge of the basilar process of the sphenoid and occipital bases. To conclude the account of the processes and sinuses of the dura mater, afalx cerebelli is found in the median plane below, containing a sinus within its edge, which opens into the torcular Herophili; finally, four sinuses, the anterior and posterior occipital sinuses, are disposed around the margin of the foramen magnum, of which the posterior are often of great size, unite with the anterior, and open into either lateral sinus. Remove the occiput by sawing through the bone vertically behind the petrous portion of the temporal bone: you observe the laminated surface of the cere¬ bellum, its hemispheres, and the narrower central part, the pars media, or vermiform processes ; the horizontal fissures on either side, out of which bands of medullary matter emerge, and meeting before, become a broad and thick arch, the pons Varolii, thrown over the con¬ verging crura of the cerebrum; the Vieussenian valve, consisting of a central slip of cineritious matter longi¬ tudinally and transversely furrowed, and margined by two rounded pillars of medullary matter, attached to the middle and fore part of the cerebellum.