DISEASES OF THE NERVOUS SYSTEM. 243 



What is meant by a malingerer? 



A malingerer is an animal that is apparently simulating dis- 

 ability; the animal is usually down, and will make no efforts to get 

 up, even after being whipped, etc. 



Define spasm. 



Spasm signifies an abnormal and often violent involuntary 

 muscular contraction, with or without loss of consciousness. 



How are they divided clinically ? 



Into tonic spasms and clonic spasms. 



What are tonic spasms ? 



Tonic or tetanic spasms are those where the muscular con- 

 tractions are constant or continuous for a measurable length of time. 



Define clonic spasms. 



Clonic spasms are those that show the contractions to rapidly 

 intermit, and may be general or local. 



What is cramp ? 



This may be defined to be a tonic spasm of muscles associated 

 with intra-muscular pain. 



Describe reflex action. 



A reflex action may be defined to be a movement or a secretion 

 which is the result of the transformation of a centripetal im- 

 pression into a centrifugal impulse. 



What apparatus is required ? 



The shin or mucous membrane, or deeper structures, to receive 

 the impression; a sensory afferent nerve to convey it; a nervous 

 centre to receive and transform it; a motor or efferent nerve to trans- 

 mit the impulse to the muscle, the wall of a vessel, a gland, etc. 



Normally, many functions of the animal body are performed 

 by reflex action; the secretion of glands, etc., the movements of 

 hollow organs, the movements of blood-vessels, as well as muscles. 



