460 Anatomy Applied to Medicine and Smgeiy. 



might be wounded were the knife directed outwards in 

 opening a tonsillar abscess, hence, to avoid this. accident, 

 the knife should be directed backwards and inwards. Oc- 

 casionally, alarming or even fatal haemorrhage, during 

 excision of a tonsil, may occur from enlarged tonsillar 

 arteries. 



The Soft Palate. Hanging down from the hard 

 palate and separating the mouth from the pharynx is the 

 soft palate. This is formed, from before backwards, in 

 the middle line, by the following structures, viz.: (1) 

 Mucous membrane; (2) submucous tissue, with vessels, 

 etc.; (3) palato-glossus ; (4) tensor palati; (5) anterior 

 fasciculus of the palato-pharyngeus ; (6) levator palati 

 and azygos uvulae muscles; (7) posterior fasciculus of 

 the palato-pharyngeus; (8) submucous tissue and vessels, 

 nerves, etc., and, lastly, (9) the posterior mucous mem- 

 brane. The soft palate is about a quarter of an inch in 

 thickness, and, when cleft, the muscles widening the fis- 

 sure are the tensor and the levator palati, while the su- 

 perior constrictor closes it during the act of swallowing. 



The Pharynx is composed of the pharyngeal aponeu- 

 rosis, lined by mucous membrane, internally, and covered 

 by the constrictor muscles, externally. It extends from 

 the base of the skull, above, to the lower border of the cri- 

 coid cartilage, below, and the lower end, i.e., its junction 

 with the oesophagus, corresponds to the lower border of 

 the fifth cervical vertebra. This tube is widest two 

 inches opposite the cornua of the hyoid bone, but nar- 

 rowest three-quarters of an inch at its junction with 

 the oesophagus. The upper part of the pharynx is kept 

 patulous by the attachment of the pharyngeal aponeurosis 

 to the basilar portion of the occipital bone ; to the apices 

 of the petrous portions of the temporal bones, and to the 

 internal pterygoid plates ; while, below, the anterior and 



