26 THE VETERINARY SCIENCE. 



CHAPTER VII. 



DIGESTIVE ORGANS. 



THE whole digestive track from the mouth to the anus, 

 which is situated just below the tail, is sometimes called 

 the alimentary canal. The chief parts are the mouth, 

 pharynx, or gullet, oesophagus, or the tube which leads from the 

 gullet to the stomach and the intestines, or bowels. 

 The mouth is an oval cavity at the commencement of the 

 alimentary or digestive canal. In front of the mouth are the lips, 

 one above and one below ; at the sides are the cheeks ; it is lined 

 by what is known as the mucous membrane, which has several 

 small openings in it from the glands, which are situated around the 

 mouth, through which the saliva is poured. On the upper part of 

 the mouth the mucous membrane is thrown into ridges, or folds, 

 and are from eighteen to twenty in number. Tiiis is a point o^ 

 importance in connection with bleeding a horse with lampers. 

 Always remember it is not safe to bleed back of the third bar 

 because there is a large artery which runs down through the roof 

 of the mouth and enters up through a hole in the bone just before 

 it reaches this bar. The tongue, which has the chief nerves of the 

 sense of taste, is situated in the mouth ; this organ also has a very 

 important part to perform in masticating the food and mixing it 

 with saliva. The teeth, which also take a very active part in the 

 masticating of food, are mentioned later on in the book under the 

 heading of "Teeth." 



Salivary Glands. — These are the glands which secrete the 

 saliva that is poured into the mouth while the animal is eating. 

 There are only three pairs of much importance. One large pair, 

 one on each side of the throat below the ears, filling up the space 

 between the jaw bone and the neck ; this pair has tubes passing 

 around and under the lower jaw and up into the cheek muscles, 

 entering the mouth opposite the fourth molar tooth ; these tubes 

 are about as large as straws and convey the saliva from the gland 

 into the mouth. The next pair are situated under the pair first 

 mentioned ; their tubes enter into the bottom part of the mouth. 

 The third pair are situated under the tongue, one on each side ; 

 they pour their secretion into the mouth by several small 

 openings near the front under the tongue, which can be seen by- 

 examining closely. This is a verv important fluid in connection 

 with the diszestinsr of the food. 



