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A TEXTBOOK OF PHYSIOLOGY 



possible, however, for this to take place when the influence of the 

 cord is removed. 



The condition of the spinal cord is investigated in man by the 

 study of certain superficial or true reflexes, and of certain tendon or 





FIG. 408. 



A andjifi, The flexion-reflex observed as a reflex contraction (A) of the lioxor musclo 

 of the knee and as a reflex relaxation (B) of the extensor muscle of the knee. 

 The intensity of the stimulating shocks was feeble, hence the relatively long 

 latent period. Time in T J^ second above and in seconds below. (From Sher- 

 rington's " Integrative Action of the Nervous System," by permission of Yale 

 University Press and Messrs. Constable and Co., Ltd.) 



deep reflexes. An example of the true reflex is the plantar reflex. 

 If the finger be drawn along the sole of the foot of a normal individual, 

 the foot is drawn away; if the stimulation be gentle, the big toe in 

 the adult is turned downwards. In certain cases of organic nervous 

 disease the big toe is turned upwards (the extensor response). This 

 is known as Babinski's sign. 



Other superficial reflexes are (1) The conjunctiva!, closing the eye, 



