242 MUSCLES AND FASCIAE. 



Relations. Externally, with the integument; internally, with the Temporal 

 ape-neurosis. 



The Attrahens Aurem, the smallest of the three, is thin, fan-shaped, and its 

 fibres pale and indistinct. It arises from the lateral edge of the aponeurosis of 

 the Occipito-frontalis ; its fibres converge to be inserted into a projection on the 

 front of the helix. 



Relations. Externally, with the skin ; internally, with the temporal fascia, which 

 separates it from the temporal artery and vein. 



The Retrahens Aurem consists of two or three fleshy fasciculi, which arise 

 from the mastoid portion of the temporal bone by short aponeurotic fibres. They 

 are inserted into the lower part of the cranial surface of the concha. 



Relations. Externally, with the integument ; internally, with the mastoid portion 

 of the temporal bone. 



Nerves. The Attollens aurem is supplied by the small occipital ; the Attrahens 

 aurem, by the facial and auriculo-temporal branch of the inferior maxillary ; and 

 the Eetrahens aurem, by the posterior auricular branch of the facial. 



Actions. In man, these muscles possess very little action ; the Attollens aurem 

 slightly raises the ear, the Attrahens aurem draws it forwards and upwards, and 

 the Eetrahens aurem draws it backwards. 



3. PALPEBEAL KEGIOJST (fig. 148). 



Orbicularis Palpebrarum. Levator Palpebra?. 



Corrugator Supercilii. , Tensor Tarsi. 



Dissection (fig. 147). In order to expose the muscles of the face, continue the longitudinal 

 incision made in the dissection of the Occipito-frontalis, down the median line of the face to the 

 tip of the nose, and from this point onwards to the upper lip ; another incision should be carried 

 along the margin of the lip to the angle of the mouth, and transversely across the face to the 

 angle of the jaw. The integument should also be divided by an incision made in front of the 

 external ear, from the angle of the jaw, upwards, to the transverse incision made in exposing 

 the Occipito-frontalis. These incisions include a square-shaped flap which should be carefully 

 removed in the direction marked in the figure, as the muscles at some points are intimately adhe- 

 rent to the integument. 



The Orbicularis Palpebrarum is a sphincter muscle which surrounds the cir- 

 cumference of the orbit and eyelids. It arises from the internal angular process of 

 the frontal bone, from the nasal process of the superior maxillary in front of the 

 lachrymal groove, and from the anterior surface and borders of a short tendon, the 

 tendo palpebrarum, placed at the inner angle of the orbit. From this origin, the 

 fibres are directed outwards, forming a broad, thin, and flat layer, which covers 

 the eyelids, surrounds the circumference of the orbit, and spreads out over the 

 temple, and downwards on the cheek, becoming blended with the Occipito-fronta- 

 lis and Corrugator supercilii. The palpebral portion (ciliaris) of the Orbicularis 

 is thin and pale ; it arises from the bifurcation of the tendo palpebrarum, and 

 forms a series of concentric curves, which are united on the outer side of the eyelids 

 at an acute angle by a cellular raphe, some being inserted into the external tarsal 

 ligament and malar bone. The orbicular portion (orbicularis latus) is thicker, and 

 of a reddish color, its fibres, well developed, forming a complete ellipse. 



The tendo palpebrarum (tendo oculi) is a short tendon, about two lines in length 

 and one in breadth, attached to the nasal process of the superior maxillary bone 

 in front of the lachrymal groove. Crossing the lachrymal sac, it divides into two 

 parts, each division being attached to the inner extremity of the corresponding 

 tarsal cartilage. As the tendon crosses the lachrymal sac, a strong aponeurotic 

 lamina is given off from its posterior surface, which expands over the sac, and is 

 attached to the ridge on the lachrymal bone. This is the reflected aponeurosis of 

 the tendo palpebrarum. 



Relations. By its superficial surface, with the integument. By its deep surface, 

 above, with the Occipito-frontalis and Corrugator supercilii, with which it is 

 intimately blended, and with the supra-orbital vessels and nerve ; below, it covers 



