94 SUKGICAL APPLIED ANATOMY. [Chap, vi 



produced, and the aspiratory effect thus brought to 

 bear upon the cervical veins. The bleeding may be 

 copious and long continued. Thus Spencer Watson 

 reports a case where the epistaxis continued on and off 

 for twenty months without obvious cause. Martineau 

 mentions an instance in which 12 Ibs. of blood were 

 lost in sixty hours, and FVaenkel records a case where 

 75 Ibs. of blood are said to have escaped from first to 

 last. In several instances the haemorrhage has proved 

 fatal. The seat of the bleeding is often not easy to 

 detect, even when the examination is post mortem. 



The nerve supply of these parts is derived from 

 the olfactory nerve, and from the first and second 

 divisions of the fifth nerve. The lachrymation that 

 often follows the introduction of irritants into the 

 front of the nares, may be explained by the fact that 

 that part of the cavity is supplied freely by the nasal 

 nerve, a branch of the ophthalmic ti'unk. As an ex- 

 ample of transference of nerve force in the opposite 

 direction, may be noted cases where a strong sunlight 

 falling upon the eyes has produced an attack of sneezing. 

 Troubles involving the vagus nerve, such as cough 

 and bronchial asthma, have followed affections of the 

 nasal cavities. The olfactory nerves are situated high 

 up in the cavity, and thus, in smelling intently, the 

 individual sniffs deeply and dilates the nostril. The 

 inability to dilate the nostril in facial paralysis, may 

 explain the partial loss of smell sometimes noted in 

 such cases. It is said (Althaus) that anosmosia, or loss 

 of the sense of smell, when following upon an injury 

 to the head, may be due to a rupture of the olfactory 

 nerve fibres, as they pass through the cribriform fora- 

 mina. Surgery affords some examples of the possible 

 violence of the act of sneezing. Thus a man sneezed 

 vigorously when his hand was firmly supported upon 

 an object, and produced a subcoracoid dislocation of 

 his shoulder (Lancet, 1878). In another case, the 



