This section is from the book "Applied Anatomy: The Construction Of The Human Body", by Gwilym G. Davis. Also available from Amazon: Applied anatomy: The construction of the human body.
Farther back in the mouth, one sees the anterior and posterior arches of the palate or pillars of the fauces with the uvula. The anterior pillar runs from the soft palate to the tongue and is formed by the palatoglossus muscle. The posterior pillar runs from the soft palate downward to the sides of the pharynx and is formed by the Palatopharyngeus muscle. In front of these arches and
Fig. 141. - Lateral view of the faucial tonsil and pharyngeal region running from the roof of the mouth opposite the posterior edge of the last molar tooth downward to the posterior edge of the alveolar process of the lower jaw is an elevation of the mucous membrane which shows the line of junction of the hard and soft palates.
Fig. 142. - Diagram illustrating the blood supply of the faucial tonsil.
Between the pillars of the fauces lie the faucial tonsils. They are limited above by the sulcus, called the supratonsillar fossa, formed by the approximation of the pillars and a fold of mucous membrane, called the plica triangularis (His), running downward from the anterior pillar and often blending with 8 the tonsil. Below they extend a variable distance, necessitating depression of the tongue with a spatula in order to make their lower limit accessible. They lie opposite the angles of the jaw on the pharyngeal aponeurosis (p. 116) with the superior constrictor muscle and bucco-pharyngeal fascia outside. A knowledge of their structure is essential to the proper treatment of their diseases. The tonsils are oval in shape and when normal in size project but little beyond the pillars of the fauces. They are about 2.5 cm. long by 1 cm. wide and consist of about a dozen recesses or crypts formed by the folding inward of the mucous membrane. From these crypts follicles extend. The walls of the crypts contain adenoid tissue as well as mucous glands. The tonsil is held together by connective tissue which is continuous with its capsule and the submucous fibrous tissue of the pharynx. On this account while an enlarged tonsil can at times be shelled out of its bed, especially its upper portion, at others it is necessary to dissect or cut it out by means of a knife, scissors, or tonsillotome.
The blood-vessels supplying the tonsil are five in number. They are: the ascending pharyngeal branch of the external carotid, the ascending palatine and tonsillar branches of the facial, the tonsillar branch of the dorsalis lingtae, and the descending palatine branch of the internal maxillary. Ordinarily, these branches are small, but sometimes some of them are large and may cause troublesome hemorrhage. In inflammation of the tonsils, these vessels of course are larger than usual.
Fig. 143. - Point of puncture for tonsillar abscess. "If an imaginary horizontal line is drawn across the base of the uvula, and another vertically along the anterior faucial pillar, they will intersect at a point overlying the supratonsillar fossa. Just external to this is the best point for opening a quinsy." - St. Clair Thomson, M.D., Brit. M. J., March 25, 1905, p. 645.
The tonsils are subject to inflammation and tumors. Tumors are rare; they grow inward and obstruct breathing and swallowing. Attempts are made to remove them either by scraping, cutting, snaring, or burning them with the electrocautery from the mouth; or they are sometimes removed through an external incision through the neck. This latter is a very severe procedure on account of the depth of the tonsil and the number of important structures which overlie it.
Tonsillitis or quinsy is an inflammation of the tonsils which leads to the formation of an abscess. In mild cases the crypts or lacunae are affected, forming a follicular or lacunar tonsillitis. In this form epithelium and inflammatory matter are poured into the follicles and distend them, often showing as white plugs protruding from the mouth of the crypt. In its treatment, in addition to local applications, surgeons enlarge the openings into the crypts with a small knife and scoop the contents out with a sharp spoon. In severe cases, the whole substance of the tonsil and even the connective tissue around it are involved in the inflammation, forming a parenchymatous tonsillitis. It frequently proceeds to the formation of pus. When this forms in the substance of the tonsil it may break into a follicle and discharge into the throat. An abscess of the tonsil may become quite large, bulging toward the median line, and on breaking may cause suffocation by passage of the pus into the larynx. If, as is usually the case, the pus involves the tissue around the tonsil, forming a peritonsillar abscess, it pushes upward behind the anterior pillar into the supra-tonsillar fossa and bulges forward, stretching the pillar over it. To evacuate this pus an incision should be made directly anteroposteriorly, with the flat side of the blade parallel with the edge of the pillar, or a slender pair of haemostatic forceps may be used. A centimetre and a quarter (1/2 in.) is deep enough usually to plunge the knife; the point should not be pointed outwardly but directly backward. The incision should be just above the upper and lateral edge of the anterior pillar (Fig. 143). Some small vessels may bleed, but this will either stop spontaneously or may be controlled by packing. The ascending pharyngeal artery lies beneath the tonsil. The tonsil lies on the pharyngeal aponeurosis and the superior constrictor muscle, while the ascending pharyngeal artery and external carotid lie outside of them, so that both structures would have to be cut before the vessels would be wounded. The internal carotid artery lies still deeper (2 to 2.5 cm.) behind and external to the tonsil. It is usually well out of harm's way unless dilated (see page 123, Fig. 156), but the pus may burrow into it and cause fatal hemorrhage. Sometimes pus may burrow through the constrictor muscle and enter the tissues of the neck. In severe tonsillitis the deep lymphatics beneath the angle of the jaw become enlarged.
Fig. 144. - Transverse frozen section passing through the faucial tonsil and showing its relation to the internal carotid artery.
Hypertrophy of the tonsils is common and is treated by removing them entirely or level with the palatal arches. An instrument called the tonsillotome is used, or it is done with a knife or scissors or snare. Fatal bleeding has followed this operation. The blood supply to the tonsil has already been given. If the bleeding is so free as to threaten the life of a patient, the external carotid artery should be ligated as all the vessels supplying the tonsil are derived from it;
Enucleation is performed by grasping the tonsil with toothed forceps, drawing it out, and cutting it loose with knife or scissors from its attachments to the pillars and aponeurosis beneath. Sometimes after loosening its attachments above it is torn loose or shelled out, from above downward, by the finger or a blunt instrument. On account of the capsule sending prolongations into the tonsil, it cannot readily be "shelled out" and portions may remain and require to be removed with the forceps and scissors or tonsillar punch. It is a disagreeable and bloody procedure and is usually done under a general anaesthetic.
cervical caries, suppuration of lymphatic nodes, or extension of pus from the middle ear through the canal for the tensor tympani muscle. The pharyngeal aponeurosis lies under the mucous membrane and between it and the constrictor muscle. It is thick above and fades away below. It fills up the gap above between the superior constrictor and the base of the skull and is attached to the pharyngeal spine on the under surface of the basilar process. It is lined with the mucous membrane and covered by the constrictor muscles. Over all is the buccopharyngeal fascia, a thin layer continuous forward over the buccinator muscle and separated from the prevertebral fascia by very loose connective tissue. The space between these two layers of fascia is known as the retropharyngeal space and pus can follow it downward behind the pharynx and oesophagus into the posterior mediastinum. Retropharyngeal abscesses occur external to the pharyngeal aponeurosis and bulge into the throat. On account of the looseness of this aponeurosis and its lack of firm attachments, these abscesses may not bulge forward as a distinct circumscribed swelling as abscesses do elsewhere, but are more apt to gravitate downward and hang in a loose bag-like manner opposite the base of the tongue. They are not easily felt, being so soft, and to see them properly the tongue should be held down with a tongue depressor. In looking for their origin, a careful examination of the spine should be made to detect the possible existence of spinal caries or Pott's disease, and the ear should be examined for suppurative otitis media. The lymph-nodes, which sometimes give rise to these abscesses, are one or two lying on the anterior surface of the vertebral column between it and the pharyngeal aponeurosis and constrictor muscles. In evacuating these abscesses the safest way is to place the child on its back with the head hanging, the pus then gravitates toward the roof of the pharynx. The tongue is held out of the way with a tongue depressor and the abscess can be well seen and incised. If the flow of pus is free, as soon as the incision is made, if in a child, the feet may be grasped and elevated, the head hanging downward, and the pus will flow out of the mouth.
Fig. 145- - Cervical caries with retropharyngeal abscess opening just posterior to the sternomastoid muscle.
The pus may not only point in the mouth but can work its way laterally. In such a case it may pass out behind the sheath of the great vessels and make its appearance, as I have seen it, behind the posterior edge of the sternomastoid muscle. If a tumor is present in this situation, the pus may be evacuated by an incision at this point and the abscess drained there instead of making an opening through the pharynx. This, of course, tends to guard against infection from the mouth.