68 VETERINARY LECTURES 



illustrated by the everyday occurrence of slaughtered animals being 

 suspended by their Achilles tendon, or ham-strings. Tendons are 

 brought into action by the middle or fleshy part of the muscle 

 contracting and relaxing. To keep the muscles in proper order, 

 good grooming and regular exercise are highly necessary — a pro- 

 fession in itself — as in training race-horses, etc. 



125. Involuntary or Non-Striated or Non-Striped Muscle 



consists of spindle-shaped cells, each with its own nucleus. The 

 cells are arranged in such a manner that they overlap, and are 

 held together by a small amount of intercellular cementing substance. 

 They are most commonly collected into bundles of varying size, 

 which may cross each other or interlace. Although involuntary 

 muscle, as its name indicates, is beyond the control of the will, it 

 is none the less necessary that it should be supplied with nerves. 

 It is chiefly found in the walls of hollow viscera, such as the 

 stomach and intestines, the urinary bladder, the uterus, etc., and 

 also forms an important constituent in the formation of the coats 

 of bloodvessels. In the hollow viscera the muscular tissue is very 

 pale, thus differing materially in appearance from the voluntary 

 muscles of the body. The heart contains a form of muscular tissue 

 which is involuntary, but possesses a deep red colour. 



126. Muscles and Tendons are subject to injury and disease 

 of various kinds. Injury may be caused by wounds, and these 

 may be — 



(1) Incised — i.e., clean cut, as with a sharp cutting instru- 



ment. 



(2) Bruised or Contused, when caused by severe blows or 



falls. 



(3) Lacerated, when the skin and flesh are torn by a 



foreign body, as by barbed wire or a cart shaft, etc. 



(4) Punctured, when made by a pointed object, as a prick 



or probe with thorns, or stabs with pitch-forks, etc. 



(5) Gun-Shot — from shot, bullets, etc. 



(6) Poisoned — from, say, the use of arsenical sheep-dip, 



wasp-stings, snake-bites, etc. 



