Volume 180501

Anatomia Britannica; a system of anatomy and physiology, selected from the works of Haller, Albinus, Monro, etc.

Date:
1805
Catalogue details

Licence: Public Domain Mark

Credit: Anatomia Britannica; a system of anatomy and physiology, selected from the works of Haller, Albinus, Monro, etc. Source: Wellcome Collection.

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    ecular artery passes to the nose.---Besides these six, there are a great number of small holes observable on the outer surface of this bone, particularly in the two protuberances above the eye-: brows. Most of these penetrate no further than the sinuses, or _than the diploe if the sinuses ‘are wanting: they generally serve for the transmission of smal] arteries of nerves. The internal surface of the os frontis is concave, except at the orbitar processes, which are convex, to support the anterior lobes of the brain. This surface is not so smooth as the external ; for the larger branches of the arteries of the dura mater make some furrows in its sides and back parts. The sinuosities fromm the luxuriant risings of the brain, mentioned when describing the general structure of the cranium, are often very observable on its upper part; and its lower and foreparts are marked with the contortions of the anterior lobes of the brain. ‘Through the middle of this internal surface, where always in children, and sometimes in old people, the bone is divided, either a ridge stands out, to which the upper edge of the falx is fastened, or a furrow runs, in which the upper side of the superior longitudinal sinus is lodged. Perhaps this variety may be owing to the diffe- rent times of complete ossification of those parts in different sub- jects: forif the two sides of this bone mect before they arrive at their utmost extent of growth, they unite very firmly, and all their fibres endeavour to stretch themselves out where the least resistance is, that is, between the hemispheres of the brain. To support this reasoning, we may remark, that those adults whose frontal bone is divided by the sagittal suture, seldom have a ridge in this place, Immediately at the root of this ridge or furrow, there is a smal] hole, ‘which sometimes pierces.through the first table, and, in other skulls, opens into the superior sinus of the ethmoid bone within the nose. In it a little process of the falx is lodged, a small artery, and sometimes a vein, runs, and the superior lon- gitudinal sinus begins —This hole, however, is often not entirely proper to the os frontis: for in several skulls, the lower part is formed in the upper part of the base of the crista galli, which is a process of the ethmoid bone, |