Pharynx

“ In the Alloeocoela and Tricladida the pharynx is an elongate protrusible cylinder, and in the Polyclads it may be an immensely distensible frilled organ, the folds of which have independent movement, or an elongate tube. At the base of the pharynx lie the openings of salivary glands. In the Polycladida the section of the alimentary sac into which the pharynx opens is a median stomach from which the intestinal branches radiate. The stomach in few forms is provided with digestive glands. The branches possess an independent musculature and exhibit active peristalsis. ”

“ PARALYSIS OF THE PHARYNX.
Paralysis of the pharynx, or, as it is commonly called, "paralysis of the throat," is a rare but very serious disease. The symptoms are as follows: The horse will constantly try to eat or drink, but will be unable to do so; if water is offered him from a pail he will apparently drink with avidity, but the quantity of water in the pail will remain about the same; he will continue by the hour to try to drink; if he can get any fluid into the back part of the mouth it will come out at once through the nose. ”

“ The pain may be relieved by spraying with certain anodyne solutions. In the case of adenoid growths (see Adenoids) there is often an associated granular appearance of the pharynx, due to enlargement of the minute glands of the mucous membrane. The inflamed pharynx of the orator (“clergyman's sore-throat”) may be put right by lessons in elocution or by complete rest for a time. The gouty throat may call for a change of diet, or for a stay at one of the water-places where early rising, moderate food, regular exercise and the drinking of laxative waters join in restoring health. ”

“ The skull and branchial basket complete their development. At the same time the pharynx loses its connection with the rest of the alimentary canal and remains as the branchial canal. The so-called oesophagus of the adult is apparently a new formation which grows forwards and acquires a connection with the mouth. It is probable that it represents a hyperpharyngeal groove constricted off from the dorsal wall of the pharynx. ”

“ Internally, behind the mouth, there is a strong pharynx, shown in the accompanying diagram (Fig. 1) which is pushed forwards when the animal eats, and this part corresponds, according to Perrier, with the protrudable trunk or proboscis of other annelids. The pharynx leads into the œsophagus, on each side of which in the lower part there are three pairs of large glands, which secrete a surprising amount of carbonate of lime. These calciferous glands are highly remarkable, for nothing like them is known in any other animal. ”

“ The pharynx or stomodaeum is still small, the foot not yet prominent. A later stage is seen in fig. 26, where the pharynx is widely open and the foot prominent. No ciliated velum or pre-oral (cephalic) lobe ever develops. The shell-gland disappears, the mantle-skirt is raised as a ridge, the paired shell-valves are secreted, the anus opens by a proctodaeal ingrowth into the rectal peduncle, and the rudiments of the gills (br) and of the renal organs (B) appear (fig. 26, lateral view) , and thus the chief organs and general form of the adult are acquired. ”

“ Pharyngitis is an inflammation of the mucous membrane lining of the pharynx or throat. It rarely exists unless accompanied with stomatitis or laryngitis, especially the latter. In those rare instances in which the inflammation is mostly confined to the pharynx are noticed febrile symptoms—difficulty of swallowing either liquids or solids; there is but little cough except when trying to swallow ”

“ The sinus-forceps used for opening a peritonsillar abscess are thrust into the most prominent part of the swelling, and the opening enlarged by separating the blades as they are withdrawn. A slender sharp-pointed bistoury, guarded and guided by the index-finger, may be used instead of the forceps. The pus will pour out through the nose and mouth. The incision of the pharynx should be free, deep and long, and directed against the posterior wall of the pharynx and as close to the median line as possible, so as to avoid any chance of wounding the internal carotid. ”

“ It is accompanied by difficulty in mastication, and still more, where the pharynx is invaded, in deglutition; abundant frothy salivation in feeding; sometimes by true spasm of the pharynx and rejection of masticated balls of food.
Locally the buccal mucous membrane (cheeks, tongue, pillars of the fauces, etc.) exhibit ulcerations, with festooned borders, in size something between a florin and a five-shilling piece, covered with a greyish-yellow, earthy-coloured exudation adhering firmly to the subjacent parts. ”

“ From the anterior end of this groove there pass a pair of peripharyngeal ciliated tracts to the dorsal side of the pharynx where they pass backwards to the hind end of the pharynx. Morphologically the whole apparatus corresponds closely with the endostyle and peripharyngeal and dorsal ciliated tracts of the pharynx of Amphioxus. The correspondence extends to function, as the open thyroid groove secretes a sticky mucus which passes into the pharyngeal cavity for the entanglement of food particles exactly as in Amphioxus. Later on the thyroid groove becomes shut off from the pharynx ”

“ In most instances there is simply an active hyperæmia which may subside in a day or two. When more intense than this the mucous membrane of the palate, tonsils, and pharynx becomes congested and swollen, uniformly or in circumscribed areas. In some instances the submucous tissue of the pharynx is greatly relaxed, and the mucous membrane lies upon the substructure in thick folds. In others there is more or less oedema. The mucous follicles, especially those of the posterior palatine folds, are frequently swollen. ”

“ Connection is made between the middle ear and the pharynx and the pressure of the air upon the drum made equal on either side by means of the Eustachian tubes. These tubes are about an inch and a half long, have cilia, and [Pg 64] convey wax and other matter from the ear to the pharynx. Occasionally in a cold or for some other reason they become stopped up and trouble results in the middle ear. Some of the mastoid cells also connect with the middle ear and may become infected, causing mastoid disease. ”

“ Extension of the morbid process from nose to pharynx is exceedingly common. When concentrated on the pharynx there are extension of the head forward with elevation of the nose, swelling of the throat laterally or downward, uneasy movements of the jaws, salivation, difficulty of swallowing, return of ingested liquids through the nose, gulping, and a loose suffocative cough. The swelling of the throat tends to attain to large dimensions, and may threaten suffocation by interfering with the breathing. This is still further aggravated if the laryngeal mucosa is the seat of exudate. ”

“ The labrum, or upper lip, has a vertical motion, and when not in use falls over the organs beneath it; while it is covered, in its turn, by the mandibles, which are jointed on to the cheeks, and act laterally.
The pharynx is a cavity lying beneath the epipharynx, and can be closed by the latter, over which the two previously described parts lap, so that the entrance to the œsophagus is trebly protected. ”

“ Microscopic examination of the tissues of the pharynx has revealed profuse infiltration with round cells—most frequently in the mucous membrane and submucous connective tissue only, occasionally in the muscular fibres likewise. The muscles sometimes undergo the fatty degeneration, and the mucous glands both fatty and colloid degeneration. ”

“ LACERATION OF THE PHARYNX. Trauma of pharynx from objects swallowed; from whip or other instrument in choking; lesions. Symptoms: swelling; rapidly extending; dysphagia; salivation; retching; dyspnœa; roaring; asphyxia. Treatment: as for pharyngitis; open pouch, suture laceration; use antiseptics; liquid diet. ”

“ Numerous salivary glands, the secretion from which possesses toxic properties, discharge into the pharynx. The œsophagus, which follows the pharynx, and to the exterior of which numerous radiary muscles are fixed, is a suctorial organ in its entire structure. The nutriment in the larger species consists of the blood of vertebrate animals, in smaller species and in the young stages the food consists of small invertebrate animals. ”

“ The muscles lie some in the body-wall, and some traverse the body-cavity; only six pairs occur, simple, unstriated, and longitudinal. There are neither transverse nor circular muscles.
The alimentary canal is very simple and nearly straight from mouth to anus; it may be divided into pharynx, gullet, stomach, and rectum. The mouth is circular, and looks forwards and a little downwards. From the mouth opens the pharynx, a short chitinous tube, capable of eversion by being pushed forwards by the gullet; it bears half-way down a circlet of curved hooks, which open out when it is everted ”

“ Membranous pharyngitis, or herpes of the pharynx, is one of the infrequent phenomena of a not uncommon sore throat, which exhibits at first a collection of small vesicles the size of millet-seeds or larger, isolated here and there or clustered in groups on the palate and uvula, less frequently on the tonsils. Herpes of the mouth and lips sometimes coexists. These vesicles are surrounded by inflammatory areolæ. ”

“ The pharynx (p) is long, and contains an undulating membrane (u.m) on its inner side projecting out through the mouth, and numerous cilia; it leads deep into the body (p) . The first part is distinguished as the "vestibule" (v) , as into it opens the anus, and the contractile vacuole (c.v.) , the latter sometimes opening by a reservoir (r) . The body contains in the ectoplasm {157}myonema-fibrils which, by their contraction, withdraw the disc, and at the same time circular fibrils close the peristome over it. ”

“ There is no skull, and the notochord is not surrounded by any vertebral column. There are no limbs nor paired fins. There is no exoskeleton, and the ectoderm is a single layer of non-ciliated columnar cells. The mouth is ventral and anterior, the anus is ventral, posterior, and asymmetrically placed on the left side. The pharynx is a large branchial sac, having its sides perforated by many gill-slits, and is surrounded by an ectodermal enclosure, the atrium, which opens to the exterior by a median ventral atriopore. ”

“ In the lower vertebrates the primitive tube subserved also the purpose of respiration, and traces of the double function remain in the adult structure of all vertebrates (see MOUTH, PHARYNX.) In fish, the pharynx, or branchial region, suddenly becomes narrower, posterior to the gill-slits, to form the oesophagus; in higher animals the oesophagus, in the adult, is separated from the primitive pharyngeal region and lies dorsal to it. Probably, in the primitive vertebrata, the entire alimentary canal was lined with ciliated cells. ”

“ In phthisis laryngea, especially when advanced, swelling from serous effusion, to a greater or less degree, almost certainly supervenes, the œdema is found in the upper surface of the epiglottis, beneath the mucous membrane, upper and forepart of the pharynx, and occasionally also in the lips of the glottis,—an effect of the contiguous ulceration,—in the same way as œdema glottidis supervenes on ulceration of the lining membrane of fauces and pharynx ”

“ Certain arrangements of the pharyngeal wall of Ammocoetes show a remarkable resemblance to what is found in Amphioxus. The thyroid, which in the adult is a complicated ductless gland, has in the young Ammocoetes the form of a longitudinal groove of the ventral wall of the pharynx. ”

“ The dangers of feeding are that the pharynx may be filled with fluid, and the patient choke, or it may be drawn into the lungs, that the wedge with which the mouth is held open may be so loosely held that in the struggle of the patient the soft parts of the mouth may be injured, and occasionally it happens that the mere pressure of the tube causes choking. ”

“ In other cases a rigid staff, a whip, or even a probang introduced to overcome choking, is forced through the walls of the pharynx forming a pouch for the accumulation and septic fermentation of ingesta, and extensive ulcerative and gangrenous lesions. ”

“ Food is imbibed by means of the suctorial pharynx lodged in the proboscis, the sucking action being effected by means of muscles radiating from the wall of the pharynx to that of the inner surface of the exoskeleton of the proboscis. ”