624 MUSCULAR DISTRIBUTION OF THE NER\TES. 



The sole of ihe foot is supplied by the plantar nerves. The internal 

 ]:)lantar nerve gives branches to three toes and a half ; the external to 

 the remaininer one toe and a half. 



SYNOPSIS OF THE MUSCULAR DISTRIBUTION OF THE CEREBRO- 

 SPINAL NERVES. 



1. To Muscles of the Head and Fore Part of the Neck. 



The muscles of ihe orlit are mostly supplied by the third cranial 

 nerve — the superior division of that nerve being distributed to the 

 levator palpebrro and the superior rectus muscles ; and the inferior 

 division to the inferior and internal recti and the inferior oblique. 

 The superior oblique muscle is supplied by the fourth nerve, the ex- 

 ternal rectus by the sixth ; while the tensor tarsi has no special nerve 

 apart from those of the orbicularis palpebrarum, which ai'e derived 

 from the facial. 



The siqjerjic'ial omiscles of iJie face and scalp, which are associated in 

 their action as a group of muscles of expression, together with the 

 buccinator muscle, are supplied by the portio dura of the seventh 

 cranial nerve ; the retrahens auriculam and occipitalis muscles being 

 supplied by its posterior auricular branch. 



The deep muscles of ilie face, employed in mastication, viz., the tem- 

 poral, masseter, and two pterygoid muscles are supplied by the inferior 

 maxillary division of the fifth cranial nerve. 



Muscles above the hijoid lone. — The mylo-hyoid muscle and anterior 

 belly of the digastric are supplied by a special branch of the inferior 

 maxillary division of the fifth cranial nerve ; the posterior belly of the 

 digastric muscle, and the stylo-hyoid, are supplied by branches of the 

 portio dura. The genio-hyoid and the muscles of the tongue receive 

 their nervous supply from the hypoglossal nerve. 



The muscles ascending to ihe hyokl bone and larynx, viz., the sterno- 

 hyoid, omo-hyoid, and sterno-thyroid, are supplied from the ramus 

 descendens noni and its loop with the cervical plexus, while the thyro- 

 hyoid muscle receives a separate twig from the ninth nerve. 



The larynx, jiharynx, and soft palcde. — The crico-thyroid muscle is 

 supplied by the external laryngeal branch of the pneumo-gastric nerve, 

 and the other intrinsic muscles of the larynx by the recurrent laryngeal. 

 The muscles of the pharynx are supplied principally by the pharyngeal 

 branch of the pneumo-gastric ; the stylo-pharyngeus, however, is sup- 

 plied by the glosso-pharyngeal nerve. Of the muscles of the soft palate 

 unconnected with the tongue or pharynx, the tensor palati receives its 

 nerve from the otic ganglion (which also supplies the tensor tympani) ; 

 the levator palati gets a twig (Meckel) from the posterior palatine branch 

 of the sphcno-palatine ganglion, and the azygos uvulaa is probably sup- 

 plied from the same source. 



2. To Muscles "belonging exclusively to the Trunk, and Muscles 

 ascending to the Skull. 



All those muscles of ihe hade which are unconnected with the upper 

 limb, viz., the posterior serrati, the splenius, complexus, erector spinjB, 

 and the muscles more deeply placed, receive their supply from the 

 posterior divisions of the spinal nerves. 



