Demonstrations of anatomy : being a guide to the knowledge of the human body by dissection.

  • Ellis, George Viner, -1900.
Date:
1890
Catalogue details

Licence: Public Domain Mark

Credit: Demonstrations of anatomy : being a guide to the knowledge of the human body by dissection. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    i)f posterior laiiscle. Attrahciis auioni muscle. Attolleiis atirein muscle. Uctrahcns aureni cou- sist.i of two or three buuales. Use of car inu.scle.s. t)cciiiito- frontali.s, liow .seen ; take care not to cut it away. upwards, and removing the subjacent tissue, a thin fan-shaped muscular layer will come into view—the more anterior fibres consti- tuting the attrahens, and the posterior the attollens aurem muscle. On drawing forwards the eaa- a ridge marks the situation of the posterior muscle. To remove the integuments, let the scalpel be drawn about ao inch behind the ear, from the transverse cut above as far as to a level with the lobule of the ear, and then forwards below the lobuJe. Aftei- the piece of skin included by those cuts has been reflected towards the ear, the retrahent nanscle must be sought beneath the subcutaneous tissue ; it consists of rounded bundles of fibres, and is stronger and deeper than the others. The ATTRAHENS AUREM (fig. 1, is a small fan-shaped muscle, and ai'ises from the fore part of the aponeurosis of the occipito- fi-ontalis. Its fibres are directed backwards, and are inserted into a projection on the front of the rim of the ear. Beneath it are tlie superficial temporal vessels and nerve. The ATTOLLENS AUREM (fig. 1, has the same form as the preceding, though its fibres are longer and better marked. Arising also from the tendon of the occipito-frontalis, the fibres converge to their insertion into the inner or cranial surface of the pinna of the ear,—into an eminence corresponding with a fossa (that of the anti-helix) on the opposite aspect. The RETRAHENS AUFREM (musculi retrahentes, Alb., fig. 1, con- sists of two or three roundish but separate bundles of fibres, which are stronger than those of the other muscles. Tlie bundles arise from ihe root of the mastoid process, and pass almost transversely forwards to be inserted by aponeurotic fibres into the lower part of the ear (concha) at its cranial aspect. The ^wsterior auricular artery and nerve are in contact with this muscle. Action. The three preceding muscles will move the outer ear slightly in the directions indicated by their names : the anterior drawing it upwards and forwards, the middle one upwards, and the posterior backwards. The occiPiTO-FRONTALTS MUSCLE (fig. 1, ^) covers the arch of the skull, and consists of an anterior and a posterior fleshy part, with an intervening tendon. Dissection. On the same side of the head (the left) the occipito- frontalis is to be dissected. To bring this muscle into view, a cut may be made along the middle line of the skull, from the root of the nose to the occipital protuberance ; and it may be connected in front with the transverse incision on the side of the head. The flap of skin, thus marked out, is to be raised with the subjacent fat from before back ; whilst doing this the dissector will meet first with the anterior fleshy part of the muscle, next with a white shining thin aponeurosis, and lastly with the posterior fleshy belly towards the lateral aspect of the cranium. The aponeurosis of the muscle is easily taken aAvay with the granular fat superficial to it; and if the under surface of the flap of integuments presents a wliite instead of a yellow appearance, the student may suspect he is removing that aponeurosis.