2T3 The Ducts of the Human Submaxillary Gland 



in sections^ especially in the comparison with digested sections. Many 

 other methods were used and modified as the exigencies of the research 

 required. 



Gross Relations. 



The Ductus submaxillaris joins the submaxillary gland with the Car- 

 uncula sublingualis, its length vanes between four and five cm.^ its 

 diameter is between two and three mm. The dtict first becomes visible 

 as it emerges from the hilus of the gland which is situated usually near 

 the central portion of the medial surface. From the hilus it runs down- 

 wards^ inwards, and forwards, upon the external surface of the M. hypo- 

 glossus running between it and the M. myiohyoideus. After passing the 

 M. hyogiossus it passes in its course between the Glandula sublingualis, 

 the M. genioglossus and M. lingualis inferior. As it runs by the medial 

 surface of the sublingual gland it is usually in intimate connection with 

 the N. lingualis and A. sublingualis. It then terminates in the Car- 

 uncula sublingualis which opens into the mouth just at one side of the 

 Frenulum linguae. The walls of the duct are rather thin when the 

 diameter of its lumen is taken into consideration, but it is well provided 

 with elastic and fibrous tunics as well as a few smooth muscle fibres. 

 The contrast in the thickness of the walls of the D. submaxillaris and 

 D. parotidens is at first sight rather surprising, especially as the former 

 carries the thick viscid secretion of the submaxillary gland while the 

 latter forms the channel through which the thin serous product of the 

 parotid is poured into the mouth. When one considers, however, the 

 fact that the duct of the parotid is relatively exposed as it lies cov- 

 ered simply by skin and fascia, this is not so surprising, for the sub- 

 maxillary duct is well protected and sheltered by the numerons firmer 

 structures forming its environment. 



' The Gl. submaxillaris lies in the Eegio submaxillaris, adapting its 

 form apparently to the shape of the space in which it lies. It is irregu- 

 larly prismatic or triangular in shape with its large axis directed dor- 

 soventrally, slightly downward and inward so that it lies parallel to the 

 axis of the ramus of the mandible. Below it is covered by the cervical 

 fascia and M. platysma. The V. facialis communis and sometimes the 

 A. maxillaris externa passes over the inferior surface of the gland. 

 Medialwards the Gl. submaxillaris rests upon the M. mylohyoidens, M. 

 stylohyoid eus, and M. hyogiossus, while lateralwards the ramus of the 

 mandible forms its chief boundary. On the internal surface is the hilus 

 where the D. submaxillaris leaves the gland. Often there is a pos- 

 terior proloncation of the organ bnt this is usually poorly marked. A 



