PAET FIEST. 



ANATOMY OF THE HEAD AND NECK. 



THE dissection of the regions included under the general term of 

 " the head" is considered the most difficult of any in the body. 

 Comprising more important structures within smaller limits than 

 any other part, and the osseous structure of the skull constituting 

 a large portion of -their bulk, it presents mechanical obstacles not 

 easily surmounted. It is hardly possible to obtain an idea of all the 

 different component parts in one dissection, as can be done in other 

 regions of the body ; the muscles and arteries may be dissected upon 

 one side of the head, and the other reserved for the nerves ; a special 

 part is, however, desirable for the preparation of the nerves ; it should 

 not be injected, and it is well to preserve it in spirit, so slowly is 

 their dissection accomplished. 



DISSECTION I. 



EXTERNAL EAR. 



The dissection of the head is usually commenced by an examination 

 of the muscles of the ear ; for this purpose the head rests upon its side, 

 and the hair should be shaved from the scalp. A hook inserted into 

 and drawing the margin of the ear successively, backward to dissect the 

 attrahens, downward to dissect the attollens, and forward to dissect 

 the retrahens, brings in turn the tendons of the three auricular mus- 

 cles into relief; the skin over these, with the cellular tissue beneath, 

 being cautiously removed, the delicate muscular fibres, of which 

 they are composed, may be demonstrated. The dissection is some- 

 times made puzzling to the beginner by the pale color and small size 

 of the aural muscles. 



The muscles which attach the ear to the side of the head 

 are called its extrinsic muscles, and are three in number ; 

 the special muscles of its cartilage, or pinna, are called 

 intrinsic. 



The ATTRAHENS AUREM is the most anterior of the ex- 

 trinsic muscles ; it arises, pale and indistinct, from the 

 epicranial aponeurosis, just above the zygoma, and its 

 fibres are directed backward to be inserted into the anterior 

 2 



