. The anatomy of the domestic animals. Veterinary anatomy. THE PARIETAL BONES 57 The external, parietal surface (Facies parietalis) is quadrilateral and is flat and smooth in the very j'oung foal; later it presents the parietal crest. The internal, cerebral surface (Facies cerebralis) presents the internal occipital protuberance, a three-sided process which projects downward and forward into tlie cranial cavity between the cerebral hemispheres and the cerebellum; it has three concave surfaces, and borders which form part of the tentorium osseum. Behind the base of the protuberance
. The anatomy of the domestic animals. Veterinary anatomy. THE PARIETAL BONES 57 The external, parietal surface (Facies parietalis) is quadrilateral and is flat and smooth in the very j'oung foal; later it presents the parietal crest. The internal, cerebral surface (Facies cerebralis) presents the internal occipital protuberance, a three-sided process which projects downward and forward into tlie cranial cavity between the cerebral hemispheres and the cerebellum; it has three concave surfaces, and borders which form part of the tentorium osseum. Behind the base of the protuberance there is a transverse groove for the sinus com- municans of the dura mater. The posterior border is thick; it joins the scjuamous part of the occipital bone. The lateral and anterior borders are united with the parietal bones. Squamous pari of Development.—The interparietal ossi- ocdpital bone ties in membrane from two chief lateral cen- ters.^ It fuses first with the parietals, some- what later with the occipital, but the period />•*'' at which this union takes place is quite variable. The Parietal Bones The two parietal bones (Ossa parie- talia) form the greater part of the roof of the cranium; they unite in the median line, forming the parietal suture. Each is quadri- lateral in outline and has two surfaces and four borders. The external, parietal surface (Facies parietalis) is convex, and is marked by a more or less prominent curved line, the ex- ternal parietal crest; this is median in its posterior part, and is continuous with the crest of like name on the interparietal and occipital; in front it curves outward and is continuous with the frontal crest. The sur- face lateral to the crest (Planum temporale) enters into the formation of the temporal fossa, and is roughened for the attachment of the temporal muscle. The internal, cerebral surface (Facies cerel^ralis) is concave. It jjresents numerous digital impressions (Impressiones digitatse) which correspond to the
Size: 1304px × 1916px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublisherphiladelphialondon
