CHAPTER TIL 

 MYOLOGY. 



THE branch of anatomy which treats of the muscular system is 

 called Myology. The muscles are the active organs of motion, or 

 of locomotion, the bones and ligaments being passive organs of 

 the same. 



Before studying the muscles individually it is necessary to take 

 a brief view of their anatomical and histological structure. They 

 contain the specific contractile substance termed muscular tissue, 

 together with areolar and fibrous tissue, and a certain amount of 

 fatty material ; they are also furnished with nerves, blood-vessels, 

 and absorbents. 



.MUSCULAR TISSUE. 



Muscular tissue is the name applied to contractile fibres, 

 which are either collected into bundles connected at their 

 extremities, and forming distinct organs termed muscles, to 

 which the familiar name flesh is applied ; or they are found 

 helping to form the walls of the hollow viscera, as the bladder, 

 stomach, &c. 



In the first variety the fibre presents, when magnified, a striped 

 appearance, the stripes being placed transversely ; it is therefore 

 known as striped or striated fibre, and as with little exception 

 its contraction and relaxation are controlled by the will of the 

 animal, it is also termed voluntary fibre or muscle. The second 

 variety differs from the first in not being striped, and also in its 

 action being beyond the control of the will ; hence it is named 

 non-striated or involuntary fibre. The chief exceptions to this 

 general distinction occur in the heart and in the upper part of 

 the oesophagus, which contain ^voluntary striated tissue. Both 

 varieties are red in colour, but the hue of the striated kind is far 

 deeper. We therefore describe two kinds of muscular tissue, the 

 striated and the non-striated. 



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