882 



THE SPINAL CORD. 



Dorsal Roots. 



Third thoracic. — Retraction of shoulders ; 

 contraction in part of triceps occasion- 

 ally well marked ; dilatation of ho- 

 monymous pupil. 



Second thoracic. — Movement at shoulder, 

 slight flexion of thumb and digit ; 

 sometimes contraction in triceps ; some- 

 times dilatation of homonymous pupil. 



First thoracic. — Movement at shoulder, 

 certainly sometimes retraction ; con- 

 traction in part of triceps ; adduction 

 and flexion of thumb and other digits ; 

 extension of elbow, sometimes flexion 

 at elbow ; with stronger stimulation 

 slight flexion and some pronation at 

 wrist. 



Eighth cervical. — Adduction and flexion of 

 thumb, flexion of other digits, flexion 

 more often extension at wrist ; drawing 

 inward and downwards of shoulder, 

 retraction of upper arm. At elbow 

 rarely extension, sometimes flexion ; 

 during the latter movement the supi- 

 nator longns acts, but the biceps acts 

 very little. When the examination of 

 the root is conducted by splitting it in 

 three fore-and-aft divisions, extension 

 at elbow and triceps contraction are 

 less common from the foremost than 

 from the hindmost division ; and flexion 

 and supinator longus action more com- 

 mon from the foremost than from hind- 

 most division. 



Seventh cervical. — Adduction and flexion of 

 thumb and flexion of other digits ; 

 flexion of elbow ; retraction of shoulder. 



Ventral Roots. 



Sixth cervical. — Flexion of elbow ; adduc- 

 tion and flexion of thumb ; flexion of 

 other digits, and retraction of shoulder 

 less marked than with Root 7. 



Fifth cervical.—- Flexion at elbow ; move- 

 ment at shoulder, sometimes retraction, 

 sometimes drawing up ; adduction and 

 flexion of thumb. Sometimes the 

 movement at shoulder is simply ad- 

 duction. 



Second thoracic. — Retraction of shoulder ; 

 slight flexion of wrist ; flexion of fingers 

 and thumb with opposition of the 

 latter ; sometimes slight pronation at 

 wrist ; lateral curving of the spinal 

 column. Dilatation of pupil ; eye opens. 



First thoracic. — Retraction of shoulder ; 

 slight lateral flexion and retraction of 

 neck ; slight extension at elbow, 

 flexion at wrist with pronation ; flexion 

 of fingers ami thumb witli opposition of 

 the latter : there is usually a slight ab- 

 duction of wrist toward ulnar side. 



Eighth cervical. ■ — The shoulder drawn 

 downwards (latissimus dorsi). The ad- 

 duction is not so extreme as in case of 

 Root 7. Kotation inwards of arm ; 

 flexion and pronation of wrist ; flexion 

 of fingers, and of thumb with opposi- 

 tion. 



Seventh cervical. — Retraction and strong 

 adduction at shoulder with some inward 

 rotation of arm ; the arm is carried 

 across the body. Extension of elbow ; 

 slight flexion at wrist and some pro- 

 nation ; slight flexion of the fingers. 

 The shoulder is drawn downwaids. 

 Slight retraction and lateral flexion of 

 neck. 



Sixth cervical. — Moderate adduction at 

 shoulder ; strong flexion of elbow ; 

 slight extension of digits and hand 

 (not in every individual). Some supi- 

 nation of wrist ; slight extension of 

 wrist in most individuals, but in a few 

 flexion and not extension of wrist. In 

 one individual flexion of fingers was 

 obtained from this root, but that may 

 have been due to mechanical effect of 

 extension of wrist, which if extreme in 

 Macacus partially flexes the fingers. 

 Very slight lateral flexion of neck toward 

 side stimulated and slight retraction 

 of neck and bead. 



Fifth cervical. — Elevation, abduction, and 

 some outward rotation of the shoulder ; 

 flexion of elbow, the wrist becoming 

 slightly supine ; slight radial abduc- 

 tion of wrist ; very slight lateral 

 flexion of neck toward side stimulated, 



