CONDUCTION PATHS 



901 



2. Ganglion-cells of retina give origin to — 



(a) Optic stratum of retina. 

 (6) Optic nerve. 



(c) Optic chiasma; fibres from nasal side of retina cross in chiasma to opposite side; 



fibres from lateral side of retina continue on same side in — 



(d) Optic tract to — 



3. Pulvinar of thalamus, lateral geniculate body, and nucleus of superior quadrigeminate 

 body. 



(a) Fibres from nucleus of superior quadrigeminate body pass ventrally, to nuclei of 



origin of oculomotor and trochlear nerves and to medial longitudinal fasciculus 

 of same and opposite sides, and from it are distributed to nucleus of origin of 



abducens. 

 (6) Fibres from lateral geniculate body and pulvinar pass through occipitarportion 



of internal capsule and occipito-thalamic radiation (optic radiation) to cortex of 



occipital lobe (visual area). 



Fia. 709. — Diagram of Principal Pathways of Optic Apparatus. (After Cunningham.) 



CORP.GEN. 



B 



4. Cells of visual area of cortex send fibres through occipito-thalamic radiation and 

 occipital portion of internal capsule to nucleus of superior quadrigeminate body 

 (occipito-mesen cephalic fasciculus), and thence, probably interrupted by ceUs of 

 this nucleus, to nuclei of eye-muscle nerves. 



5. CeUs of nucleus of superior quadrigeminate body and pulvinar send fibres by way of 

 medial longitudinal fasciculus into lateral and ventral funiculi of spinal cord (see 

 fig. 619), chiefly of the opposite side. Fibres from the quadrigeminate body cross 

 mid-line chiefly in decussation of 'optic-acoustic reflex path' (fig. 662). 



6. The smaller cells of the supero-mesial group of the nucleus of the oculomotor nerve 



(nucleus of Edinger and Westpha]) send axones, by way of the trunk of the nerve 

 and the short root of the cihary gangUon, which terminate about cells in — 



7. The ciliary ganglion, whose cells send axones to enter the ocular bulb and termi- 



nate upon the smooth muscle fibres of the cihary body and iris. 



Skin-pupillary reflexes. 



1. Peripheral processes of spinal ganghon cells terminating in the skin and central 

 processes of same entering by way of dorsal roots of cervical nerves to bifurcate in 

 spinal cord and give terminal twigs about — 



2. CeUs of the dorso-lateral group of the ventral horn of the same and opposite sides. 

 These cells send (visceral efferent) axones to terminate about ceUs in — 



