CHAPTER VI. 



MUSCULAR TISSUE : STRIATED OR STRIPED ; NON-STRIATED OR 

 PLAIN; ATTACHMENT OF MUSCLES TO SKELETON; PROMI- 

 NENT MUSCLES OF HEAD AND TRUNK ; PROMINENT MUSCLES 

 OF LIMBS. 



MUSCULAR tissue is the tissue by means of which the active 

 movements of the body are produced. It is a higher kind of 

 tissue than the connective, which, as we have seen, is used 

 chiefly for mechanical purposes. Muscular tissue is irritable, 

 and if we irritate or stimulate it, it will respond. We may irri- 

 tate or stimulate the bones, ligaments, 

 or other connective tissue structures 

 and they will not respond, they will 

 remain immovable ; if, however, we 

 stimulate muscular tissue, it will show 

 its response to the stimulation by 

 contracting. This power of the 

 muscle to contract is called muscular 

 contractility. All muscular tissue 

 consists of fibres, and whenever a 

 muscle fibre contracts, it tends to 

 bring its two ends, with whatever may 

 be attached to them, together. Influ- 

 ences which irritate or stimulate 

 muscle fibres are spoken of under 

 the general name of stimuli. 



Muscle fibres are of two different 

 kinds, and we therefore distinguish 

 two varieties of muscular tissue, the striped or striated, and the 

 plain or non-striated. The striated muscle is nearly always 

 under the control of the will, and is often spoken of as voluntary 



62 



FIG. 51. MUSCULAR FIBRE. 

 Highly magnified. (E. A. S.) 

 The nuclei are seen on the flat at 

 the surface of the fibre, and in 

 profile at the edges: the sar- 

 coleuiina is not seen. 



