300 A^ETERINARY PHYSIOLOGY 



artery, the terminal branches of which have a very free 

 communication with those of the portal vein. 



(3) The Pancreas hke the liver develops as an outgrowth 

 from the intestine. It is an enzyme secreting gland. In 

 the lobules are certain little masses of epithelium-like cells 

 closely packed together — the islets of Langerhans (fig. 148). 



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Fio. 14S. — Section of Pancreas to show Acini of Secreting Cells ; a large 

 duct (a), and in the centre an Island of Langerhans (b). 



The Nerve Supply of the Alimentary Canal. 



The muscles round the mouth are supplied by the fifth, 

 seventh, and twelfth cranial nerves. The nerve supply of 

 the salivary glands will be considered later. The pharynx 

 and the oesophagus are supplied by the ninth and tenth 

 cranial nerves, and by fibres from the sympathetic. 



The stomach and small intestine get their nerve fibres 

 from the vagus and the abdominal sympathethic (p. 198). 

 The large intestine is supplied by the abdominal sympathetic, 

 the various fibres passing through the abdominal sym- 

 pathetic ganglia. The uj^per part is also supplied from the 

 vagus and the lower part from the pelvic nerves. In the wall 



