204 SALIVARY GLANDS. 



5. In the human skull study the joint by which the lowtrr- 

 jaw is articulated. 



6. The masseter muscle passes from the angle of the 

 jaw to the lower border of the bridge, or arch, of the cheek- 

 bone. 



7. The temporal muscle is attached to the thin wing or 

 process of the jaw in front of the hinge, and passes up inside 

 of the arch of the cheek-bone to spread over the temple. 

 Place the tips of the fingers on the temples, and shut the 

 teeth firmly together. The hardening of the temporal muscle 

 is felt. 



8. Find the hole on the inside of each half-jaw where the 

 nerves and blood-tubes entered to supply the teeth. 



The Salivary Glands make the Saliva and pour it into the 

 mouth. There are three pairs of salivary glands, the Parotid, 

 just back of the angle of the jaw, under the ear ; its duct 

 runs forward under the skin of the cheek, and opens on the 

 inside of the cheek opposite the second molar of the upper 

 jaw. The Submaxillary gland lies under the angle of the 

 jaw ; its duct opens under the tongue near the front of the 

 mouth. The Sublingual gland is in front of the submaxillary, 

 and empties near the same place as the submaxillary. 



Action of the Salivary Glands. The salivary glands 

 pour into the mouth a liquid which they manufacture from 

 materials taken from the blood. In structure the gland may 

 be compared to a bunch of grapes, the grapes representing 

 the little cavities, with a wall of cells which make the saliva ; 

 from these cavities the liquid passes into the individual duct, 

 represented by the stem of a single grape ; many of these 

 uniting form the main stem, which corresponds to the main 

 duct. A rich network of capillaries surrounds the gland ; 

 when the gland is at work it receives more blood ; the liquid 

 part of the blood (plasma) soaks out through the capillary 



