MUSCLE 



794 



MUSCOID 



of the will, as the non-striated muscles. They vary 

 from 75-225 u in length, and from 4-8 fi in width. 

 The cells are surrounded by a delicate hyaline sheath, 

 and possess a rod-shaped nucleus. See M., Un- 

 striped. M. -juice. Same as M. -plasma. Ms. of Mas- 

 tication, the masseters, temporals, and external and 

 internal pterygoid muscles. M., Non-striated, one 

 composed of spindle-shaped involuntary muscle-fibers. 

 M. -nucleus, the nucleus of a muscle-fiber. M., 

 Organic. See Involuntary. Ms. of Organic Life, 

 Unstriped or Involuntary Ms., those composed of 

 spindle-shaped, contractile fibers and nucleated cells 

 collected in bundles. A table arranged alphabet- 

 ically is appended, showing the principal muscles of 

 the human body, with their origin, insertion, innerva- 

 tion, and function. M., Papillary, the muscular emi- 

 nences in the ventricles of the heart, from which the 

 chordae tendineae arise. M., Pennate, M., Penni- 

 form, a muscle with a central axis, from which the 

 fibers radiate on each side. M., Perforated [of Cas- 

 serins). See M., Coraco-brachialis , in Table. M., 

 Peripenial, a layer of involuntary muscle beneath the 

 skin of the penis. M. -plasma, a liquid obtained from 



A. Striped muscle of frog, sarcolemma raised in the form of a 

 bleb. B. Ruptured fiber with sarcolemma. C. Fiber rup- 

 tured by a hair. D. Effect of acetic acid 011 a muscle fiber. 

 E. Muscle-discs. {Stirling.) 



fresh muscle by expression, preferably after freezing. 

 Its coagulation is the essential condition of rigor mortis, 

 and is comparable to the coagulation of blood. The 

 solid proteid thus separated is called myosin. Two of 

 its proteids, paramyosinogen and myosinogen, go to 

 form the clot, while the other three, myoglobulin, al- 

 bumin, and myoalbuminose, remain in the muscle- 

 serum. M. -plate. See Myocomma, and Myotome. 

 M. -prism, a muscle-rod. M. -reading, the detection 

 of a person's thoughts and emotions by the in- 

 voluntary action of his muscles. Ms. of Respiration, 

 those involved in the ordinary processes of breathing. 

 Those concerned in inspiration are the diaphragm, 

 the intercostals and the long and short elevators. 

 Other muscles, including the trapezius, scaleni and 

 pectoralis minor, are brought into play during forced 

 inspiration. Ordinary expiration is non -muscular, the 

 act being a purely passive one; forced expiration. 

 however, brings into play most of the abdominal 



muscles. M.-rod, one of the ultimate divisions of 

 the dim band of a muscle-compartment. M. -serum, 

 the liquid residue left after the separation of the clot 

 by coagulation of muscle-plasma. M., Skeletal, any 

 one of those muscles attached to and acting on the 

 skeleton. M. -sound, the sound produced by the 



Isolated Smooth Muscular Fibers. 

 Nitric acid. X 300. {Stirling.) 



contraction of a muscle. M. -spindle, structures 

 described by Kiihne and considered by Kirschner as 

 special sensory nerve-endings, and by Kolliker to 

 be transient developmental structures connected with 

 the cleavage of the muscle-fibers (Piersol). M., Stalk, 

 a differentiation of the ectoplasm of the Vorticelm 

 which, in contracting, rolls the stalk up spirally. M. ( 

 Striated, a muscle constituted of striped muscle-fibers. 

 M., Striped. Same as M. , Striated. M. -sugar. See 

 Inosite. M., Tailor's. Synonym of the sartoriiis mus- 

 cle. See Table. M. -telegraph, an apparatus arranged 

 by DuBois-Reymond especially for replacing the myo- 

 graph in experiments during lectures. The muscle is i 



a 



\ 



Muscular Fibers of the Human Heart. (Stirling.) i 



fixed in a vise ; its other end is connected by a hook 

 with a thread running over a reel. The reel supports 

 a long indicating hand to which a colored disc is at 

 tached. The muscle, in shortening, turns the whee 

 and lifts the disc, which is easily seen from a c< 

 erable distance. A second thread, slung over th< 

 reel, supports a brass vessel, which may be filled witl 

 shot, so as to apply any desired weight to the muscle 

 M. -tumor, a myoma, a. v. M., Unstriated, M. 

 Unstriped. See M. , Avn-striated. M., Visceral. ;m 

 one of the muscles connected with the viscera 

 they are not under the command of the will. M 

 Voluntary. See A/., Striped. 

 Muscoid [mus'-koid) \niuscus, moss; cidoc, like 

 Moss-like. 



