OCCIPITO-FRONTALIS MUSCLE. 



19 



the cranium, and is continuous across the middle line with the same struc- 

 ture of the opposite half of the head. On the side it gives origin to the 

 auricular muscles ; and a thin membrane is here prolonged from it over the 

 fascia covering the temporal muscle, to be fixed to the side of the head. 



Fi 



15. Attollens aurem. 



16. Attrahens aurem. 



EXTRINSIC MUSCLES OF THE EAK. 



17. Retrahens aurem, only partly seen. 



Posteriorly, the aponeurosis is attached to the superior curved ridge of the 

 occipital bone between the fleshy parts of the muscles of opposite sides. 

 The aponeurotic expansion is closely united to the skin ; but it is connected 

 to the pericranium only by a loose areolar tissue devoid of fat, so that it 

 moves freely over the skull. 



Superficial to the occipito-frontalis are the cutaneous vessels and nerves 

 of the scalp. In front the fleshy fibres of opposite sides are joined above 

 the root of the nose. 



Action. When the anterior belly contracts it elevates the eyebrow, 

 making smooth the skin at the root of the nose, and wrinkling transversely 

 that of the forehead ; and continuing to contract, it draws forward the 

 scalp. The posterior belly will move back the scalp ; and the bellies acting 

 in succession will carry the hairy scalp forwards and backwards. 



Dissection. After the removal of the superior auricular muscles and the 

 temporal vessels, together with the epicranial aponeurosis and its lateral 

 prolongation, the attachment of the temporal fascia on the side of the head 

 may be seen. 



The temporal fascia is a white, shining membrane, which is stronger 

 than the epicranial aponeurosis, and gives attachment to the subjacent 

 temporal muscle. Superiorly it is inserted into the curved line that limits 

 the temporal fossa on the side of the skull ; and inferiorly, where it is nar- 

 rower and thicker, it is fixed to the zygomatic arch. By its cutaneous 



