64 ANATOMY AND PHYSIOLOGY. 



the orbit. Inserted into the inner corner of the eyes. Use To 

 shut the eyes. 



Levator palpebra superioris^ arises from the bottom of the orbit, 

 near the optic foramen. Inserted into the cartilage of the tarsus of 

 the upper eyelid. Use To open the eye by raising the upper 

 eyelid. 



MUSCLES OF THE EYEBALL. 



Rectus superior rectus inferior rectus internus rectus exter- 

 nuS) arises from around the optic foramen of the sphenoid bone, at 

 the bottom of the orbit. Inserted into the anterior part of the 

 tunica sclerotica, opposite to each other. The action of the rectus 

 superior is to raise the eye upwards of the inferior, to pull it 

 downwards of the internus, to turn it to the nose of the externus, 

 to move it outwards. 



Obliquus superior arises near the optic foramen and passes 

 through a trochlea in the internal canthus of the eye, and is re- 

 flected to be inserted into the posterior part of the bulb, between 

 the rectus and the entrance of the optic nerve. Use To roll the 

 eye, and turn the pupil downwards and outwards. 



Obliquus inferior arises from the ductus nasalis, and is inserted 

 opposite to the former. Use To roll the eye. 



MUSCLES OP THE NOSE AND MOUTH. 



Levator labii superioris alaque nasi arises from the nasal process 

 of the superior maxillary bone. Inserted into the upper lip and 

 ala of the nose. Use It raises the upper lip and dilates the 

 nostrils. 



Levator labii superioris proprius arises from the upper jaw, under 

 the orbit. Inserted into the middle of the lip. Use To pull the 

 Upper lip directly upwards. 



Levator anguli oris arises from the orbitar foramen of the sup. 

 max. bone. Inserted into the orbicularis, at the angle of the 

 mouth. Use To raise the corner of the mouth. 



Zygomaticus major arises from the os jugale, near the zygomatic 

 future and runs downwards. Inserted into the angle of the mouth, 

 with the depressor of the lip. Use To inflate the cheek and raise 

 the angle of the mouth. 



Zygomaticus minor arises above the zygomaticus major. In- 

 serted into the angle of the mouth. Use To raise the angle of the 

 mouth outwards. 



Buccinator arises from the sockets of the last molares, and the 



