Chap. XX] 



SUMMARY 



437 



Sense of 

 Equilibrium 



Sight 



Ascessory 

 Organs 



Function of the vestibule and semicircular canals. 



Lining membrane supplied with sensory hairs which con- 

 nect with vestibular nerve. 



Contain several small otoliths which float intheendoljanph. 



Flowing of the endolyraph stimulates the sensory hairs; 

 this is transmitted to the vestibular nerve, thence to 

 auditory nerve, thence to brain. 



' Eye. 



Optic nerve. 

 Centre in brain. 



Eyebrows. 

 Accessory Eyelids. 



organs ] Lacrimal apparatus. 

 Muscles. 



Vibrations in the ether enter eye and strike on retina, 

 which contains end organs of the optic nerve; thence 

 sensation is carried to visual centre in brain. 



Visual ap- 

 paratus 



Eyebrows 



Eyelids 



Arched eminences of skin furnished with 

 short, thick hairs. 



Control to a limited extent amount of light 

 admitted to eye. 



' Folds of connective tissue covered with 

 skin, lined with mucous membrane (con- 

 junctiva), which is also reflected over 

 the eyeball. Provided with lashes. 



Closed by orbicularis palpebrarum muscle. 



Upper lid raised by levator palpebrae su- 

 perioris. 



Slit between lids called palpebral fissure. 



Inner angle of slit called internal canthus. 



Outer angle of slit called external canthus. 



Function is protection. Serve as shades. 



Tarsal glands are a row of glands embedded 

 in tarsal cartilage of each lid. 



