The complete works of John Hunter, F.R.S (Volume 2).

  • Hunter, John, 1728-1793.
Date:
1841
Catalogue details

Licence: Public Domain Mark

Credit: The complete works of John Hunter, F.R.S (Volume 2). Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    the inside of the jugum, and is inserted into the coronoid process of the lower jaw, on both sides tendinous and fleshy, but principally tendinous. It reaches further down upon the inside of the coronoid process than upon the outside, the insertion being continued as low down as the body of the bone. The posterior and inferior edge of this muscle passes over the root of the zygomatic process of the temporal bone as over a pulley, which confines the action of the muscle to that of raising the lower jaw more than if its fibres had passed in a direct course from their origin to their insertion. The use of the temporal muscle, in general, is to raise the lower iaw; and as it passes a little forwards to its insertion, it must bring the condyle at the same time backwards, and so counteract the ptervgoideus externus of the opposite side ; and if both muscles act, they Counteract both the pterygoidei, by bringing back the whole of the jaw. Of the Internal Pterygoid Muscle. The internal pterygoid muscle is situated upon the inside of the lower iaw, opposite to the masseter. It is a strong short muscle, a little flattened, especially at its insertion. It arises tendinous and fleshy from the whole internal surface of the external ala ot the sphenoid bone; from the external surface of the internal ala, near its bottom; from that process of the os palati that makes part ot the fossa pterygoidea ; likewise from the anterior rounded surtace of that process where it is connected to the os maxillare supenus. From tnence the muscle passes downwards, a little outwards and backwards, and is inserted, tendinous and fleshy, into the inside ot the lower jaw, from the angle up almost to the groove for_ the admission of the maxillary nerve, where the surface of the bone is remarkably scabrous. . . The use of this muscle is to ra1Se the lower jaw ; and from s direction, one would suspect that it would bring the condyle^a litUe forwards; but this motion is contrary to that of the lowei jaw, tor it is naturally brought back when raised. Of the External Pterygoid Muscle. The external pterygoid muscle is situated immediately between the external surface of the external ala of the pterygoid process and the condyle of the lower jaw, lying, as it were, horizontally aFoJ the bSs of the skull. It is somewhat radiated in some bodifs broad at the origin, and small at the insertion; bu he Later part of it forms a round strong fleshy belly, so that the nirt that makes it of the radiated kind is thin. P The th i and ordinary portion of it arises tendinous and fleshy, from almost the whole external surface of the external ala of the