66 ANATOMY AND PHYSIOLOGY. 



near the tragus. Inserted into the upper part of the tragus. Use 

 to depress the concha, and pull the tragus a little putwards. 



Antitragus arises from the root of the inner part of the helix. 

 Inserted into the upper part of the antitragus. Use To dilate the 

 mouth of the concha. 



Transversus auris arises from the upper part of the concha. In- 

 serted into the inner part of the helix. Use To draw these parts 

 towards each other. 



MUSCLES OF THE INTERNAL EAR. 



Laxator tympani arises from the spinous process of the sphsenoid 

 bone. Inserted into the long process of the malleus. Use To 

 draw the malleus obliquely forward towards its origin. 



Tensor tympani arises from the cartilaginous extremity of the 

 Eustachian tube. Inserted into the handle of the malleus. Use 

 To pull the malleus and membrane of the tympanum towards the 

 petrous portion. 



Stapedius arises from a little cavern in the petrous portion, near 

 the cells of the mastoid process. Inserted into the posterior part 

 of the head of the stapes. Use To draw the stapes obliquely 

 upwards towards the cavern. 



MUSCLES OF THE LOWER JAW. 



Temporalis arises from the lower part of the parietal bone and os 

 fronds, squammous part of the temporal bone, back part of the os 

 jugale, the temporal process of the sphsenoid bone, and the apone- 

 urosis which covers it. Inserted into the coronoid process of the 

 lower jaw, its fibres being bundled together and pressed into a 

 small compass, so as to pass under the jugum, or zygoma. Use 

 To move the lower jaw upwards. 



Masseter arises from the sup. max. bone, near the os jugale, and 

 from the anterior part of the zygoma. Inserted into the angle of the 

 lower jaw upwards to the basis of the coronoid process. Use To 

 raise and move the jaw a little forwards and backwards. 



Pterygoideus internus arises from the internal pterygoid process 

 of the sphsenoid bone. Inserted into the lower jaw, on its inner 

 side, and near its angle. Use To raise the lower jaw and draw it 

 a little to one side. 



Pterygoideus externus arises from the external pterygoid process. 

 Inserted into the condyloid process of the lower jaw and capsular 

 ligament. Use To move the jaw, and to prevent the ligature of 

 the jaw from being pinched. 



