134 VETERINARY STATE BOARD 



(c) Arrest or restraint of a process effected by nervous influence. 



(d) The power possessed by nerve centres to originate nervous 

 impulses. 



How does the nervous system influence secretion? 



Through reflex action, as shown by the secretion of saliva pro- 

 duced by the presence of food in the mouth, or of the gastric juice 

 by food in the stomach. 



What are (a) voluntary movements, (b) reflex movements? 



(a) Movements under control of the will. 



(b) Involuntary movements produced by stimulation of a 

 peripheral nerve. 



How many pairs of cranial nerves are there? Give the name and the 

 function of any one pair. 

 There are twelve pairs of cranial nerves. The first pair, olfac- 

 tory, is concerned 'in the sense of smell. 



Give the function of the optic nerve. 



(The second pair of cranial nerves.) The nerve of sight. 



Give the function of the third pair of cranial nerves. What muscles 

 does it supply? 



(The oculomotor.) The motor nerve to the eyeball. It supplies 

 all the muscles of the eye, except the external rectus and superior 

 oblique; it also supplies the muscle of the upper lid and sends 

 fibres to the iris and ciliary muscle. 



State the function of the fourth pair of cranial nerves. 



(Patheticum.) The motor nerve of the superior oblique muscle 

 of the eyeball. 



State the function of the fifth pair of cranial nerves. 



(Trifacial.) This is a mixed nerve, i.e., both motor and sensory. 

 It supplies motor power to the muscles of mastication, sensation 

 to the side of the face, lips, mouth, temple, part of the ear, cornea, 

 conjunctiva, nasal mucous membrane and anterior two-thirds of 

 the tongue. It also sends trophic fibres to the eyeball. 



What is the function of the sixth pair of cranial nerves? 



(Abducens.) Supplies motor power to the external rectus 

 muscle of the eyeball. 



State the function of the seventh pair of cranial nerves. 



(Facial.) Motor nerve to the muscles of the middle ear, exter- 

 nal ear, cheeks, lips, nostrils and orbicular muscles of the eye. 

 Through its chorda tympani branch, it supplies the anterior por- 

 tion of the tongue with taste and sends secretory fibres to the maxil- 

 lary gland, and dilator fibres to the blood-vessels. 



