PHARYNX. 



945 



leave its inferior fundus uncovered by it ; con- 

 sequently the bladder when distended may be 

 punctured above the pubis or through the 

 rectum without injuring the peritoneum. 



In the mesenteries, omenta, and other peri- 

 toneal duplicatures, where the external surface 

 of the peritoneum adheres to itself, the adhesion 

 is generally extremely intimate. They are most 

 separated where deposits of fat have taken 

 place between them. The recto-vesical folds 

 and the broad ligaments of the uterus alone, 

 of all the peritoneal duplicatures, have their 

 layers loosely adherent. 



The peritoneum is very frequently the seat of 

 extensive inflammation, the lymph effused in 

 which process, besides causing adhesions of 

 the abdominal viscera to one another and to 

 the parietes, frequently covers the free peri- 

 toneal surface with a thick adherent layer or 

 false membrane; and this, like some other 

 tissues formed from lymph, shrinks or cicatrizes 

 in every direction, and thereby produces some 

 very curious secondary effects. In such cases, 

 if the great omentum is free at its lower border, 

 it becomes tucked up to the greater convexity 

 of the stomach and apparently obliterated ; or 

 if adherent, as to a hernial sac, the shrinking 

 of the new tissue that covers it drags down the 

 stomach. The thin sharp edges of the liver 

 become rounded by this agent, and the calibre 

 of the intestinal tube diminished; sometimes 

 the intestine is even strictured by the contrac- 

 tion of an unusually large deposit at a par- 

 ticular part. The tendency of this tissue to 

 shrink, however, being controllable by suffi- 

 cient mechanical resistance, is most manifest in 

 those directions in which it experiences no 

 such opposition ; for which reason it tells more 

 on the length than on the circumference of an 

 intestine, and Cruveilhier met with a case of 

 chronic peritonitis in which the small intestine 

 measured only seven feet in length. If the 

 hand is placed on the belly of a person in 

 whom this condition exists, the muscles are 

 felt to glide loosely over the peritoneum ren- 

 dered tense beneath them. 



For the minute anatomy of the peritoneum 

 see SEROUS MEMBRANE. 



(Simon Rood Pittard.) 



PHARYNX and MOUTH. (Gr. (pa ? t|.) 

 The pharynx is a large, muscular, and membra- 

 nous pouch, placed behind the nose, mouth, and 

 larynx, and resting upon the cervical vertebrae : 

 it extends from the base of the skull above to a 

 level with the fourth or fifth cervical vertebra 

 and the lower border of the cricoid cartilage, 

 and is at this point continued into the oesopha- 

 gus : it occupies the middle line of the body 

 and is a symmetrical organ : of a very irregu- 

 larly funnel-shaped form, it is wide above and 

 open in front to the cavities of the nose and 

 mouth, and contracts as it descends behind the 

 larynx : by the relation of this latter organ the 

 interior of the pharynx is converted into a tube 

 to be continued downwards to the stomach 

 under the name of oesophagus. A common 

 channel to the digestive and respiratory pas- 



VOL. III. 



sages, it is alike beautifully adapted by its con- 

 struction, on the one hand to receive the food 

 and convey it onward to the alimentary canal, 

 and on the other to preserve a perfectly free 

 communication between the atmospheric air and 

 organs of respiration : to this latter function may 

 be added the power of modulating vocal sounds. 



As the pharynx is so closely associated, both 

 in function and anatomical relation, with the 

 mouth and palate, I shall subjoin to its de- 

 scription that of these latter organs. In the 

 further examination of the pharynx the fol- 

 lowing arrangement will be adopted. 1st. The 

 description of its aponeurosis and muscles. 

 2ndly. Its attachments considered generally. 

 3rdly. To examine its cavity with the several 

 openings related to it. 4thly. The mucous 

 membrane and glandular apparatus; and, 

 lastly, the vessels and nerves distributed to it. 



1. The fibrous membrane. This aponeurosis, 

 named cephalo-pharyngeal, contributes to the 

 formation of the pharyngeal parietes above, 

 and is essentially the means by which the pha- 

 rynx is affixed to the base of the skull : it forms 

 a sort of framework for the support of the mus- 

 cular and mucous tunics above, and is imper- 

 ceptibly lost as it descends between these 

 structures : it is thin but strong and well- 

 marked superiorly, and connected, by uniting 

 intimately with the periosteum, to the under 

 surface of the basilar process of the occipital 

 bone, and, by a particularly dense slip, to its 

 spine centrally ; this latter may be considered 

 as the origin of that tendinous raphe which, 

 descending in the median line along the back 

 of the pharynx, acts as an uniting medium to 

 the constrictor muscles of either side : the 

 basilar attachment of the cephalo-pharyngeal 

 aponeurosis occurs immediately anterior to the 

 insertions of the recti capitis antici muscles, 

 and is consequently some little distance in ad- 

 vance of the occipital condyles and foramen : 

 extending laterally, the aponeurosis next springs 

 from the under surface of the petrous portion 

 of the temporal bone as far outwardly as the 

 external orifice of the carotid canal, just an- 

 terior and internal to which it turns suddenly 

 forwards and inwards, forming a sharp angle, 

 then passes beneath the inner surface of the 

 levator palati muscle, to attach itself to the car- 

 tilaginous portion of the Eustachian tube, near 

 the anterior extremity of which it terminates by 

 being gradually lost upon the mucous mem- 

 brane: descending from these several points, 

 and bounding the upper part of the pharyngeal 

 cavity posteriorly and laterally, it insinuates 

 itself between the mucous membrane and su- 

 perior constrictor muscle, and splitting up into 

 filaments which pass between the numerous 

 mucous glands that are found at this part of 

 the pharynx is lost from an inch to two inches 

 below the base of the skull : posteriorly, on 

 either side the median line, and between the 

 upper semicircular margins of the superior 

 constrictor muscles and the base of the skull, a 

 considerable part of this aponeurosis is unco- 

 vered by muscular fibres, constituting what are 

 called the sinuses of Morgagni: the fibrous 



3 p 



