Part 4

The tendo oculi serves many purposes besides giving attachment to the cartilages and muscles of the lids. One purpose is said to be to pump the tears into the lachrymal sac. Place a finger on the tendon, and feel that it tightens every time the lids are closed. The tendon, being intimately connected to the sac, draws, as it tightens, the sac wall outwards and forwards, and in this way it may pump along the lachrymal canals any fluid collected at the angle of the eye.

17. =Nasal duct.=--The nasal duct is from six to eight lines long, and narrowest in the middle of its course. Its termination in the inferior meatus lies under the inferior spongy bone, about a quarter of an inch behind the bony edge of the nostril. The appearance of the orifice in the dry bone conveys no idea of its size and shape in life; for it is diminished by a valve-like fold of mucous membrane, so that it becomes, in most cases, a mere slit, not exceeding a line in diameter.

The facility with which instruments can be introduced into the nasal opening of the duct depends upon its position as well as its size. This position varies in different instances. Sometimes it opens directly into the roof of the inferior meatus, in which case the hole is large and round, so that tears readily run into the nose. In other instances the opening is situated on the outer wall of the meatus, and is then always such a narrow fissure as to be hardly discernible. The practical conclusion then is, that a probe can be easily introduced when the opening is in the roof of the meatus, but not without difficulty and laceration of the mucous membrane when on the outer wall. This difficulty indeed may be increased by the narrowness of the meatus, arising from an unusual curvature of the spongy bone.

18. =Nose and nasal cavities.=--The line where the cartilages of the nose are attached to the nasal and superior maxillary bones can be traced with precision. The close connection of the skin to the cartilages admits of no stretching; hence the acute pain felt in erysipelas and boils on the nose. The external aperture of the nose is always placed a little lower than the floor of the nostril, so that the nose must be pulled up before we can inspect its cavities.

Looking into the nostrils, we find that the left is, in the majority of cases, narrower than the right, owing to an inclination of the septum towards the left. A communication sometimes exists between them, through a hole in the septum, as in the case of the celebrated anatomist Hildebrandt. By stretching open the anterior nares we can get a view of the end of the inferior spongy bone. The middle spongy bone cannot be seen: its attachment to the ethmoid is high up, nearly opposite the tendo oculi. The cavities are so much narrowed transversely by the spongy bones, that in the extraction of polypi it is better to dilate the blades of the forceps perpendicularly, and near the septum.

19. =Mouth.=--What can be seen and felt through the mouth? The upper surface of the tongue, ‘speculum primarum viarum,’ is a study in itself. We notice, on its under surface, a median furrow, on each side of which stands out the ranine vein, lying upon the prominent fibres of the lingualis. In the middle line of the floor of the mouth is the ‘frenum linguæ,’ with the orifice of the duct of the submaxillary gland on each side of it. The gland itself can be detected immediately beneath the mucous membrane by feeling further back near the angle of the jaw, at the same time pressing the gland upwards from below.

The long ridge of mucous membrane on each side of the floor contains the sublingual glands.

We can feel the attachment of the ‘genio-hyo-glossi’ behind the symphysis of the jaw. The division of this attachment would enable a surgeon to draw the tongue more freely out of the mouth in any attempt to remove carcinoma extending far back into its root.

There is great difference in the shape of the hard palate; this difference depends upon the depth of the alveolar processes. In some it forms a broad arch; in others it is narrow, and rises almost to a point like a Gothic arch, and materially impairs the tone of the voice.

=Throat.=--To examine the throat well, the nose should be held so as to compel breathing through the mouth. Thus the soft palate will be raised, the palatine arches widened, and the tonsils and the back of the pharynx fairly exposed. Pressing the tongue downwards, provided it be done very gently, is also of advantage. Rude treatment the tongue at once resists. The forefinger can be passed into the throat, beyond the epiglottis, as low as the bottom of the cricoid cartilage, and thus search the pharynx down to the top of the œsophagus, and the hyoid space (on each side) where foreign bodies are so apt to lodge. The greater cornu of the hyoid bone can be felt as a distinct projection on either side. In introducing a tube into the œsophagus the finger should keep the instrument well against the back of the pharynx so as to prevent its slipping into the larynx.

Pass the finger between the teeth and the cheek and feel the anterior border of the coronoid process of the jaw. On the inner side of this process, between it and the tuberosity of the upper jaw, is a recess, where a deeply-seated temporal abscess might burst, or might be opened. Behind the last molar on the inner side of the upper jaw we can distinctly feel the hamular process of the sphenoid bone; also the lower part of the pterygoid fossa, and the internal pterygoid plate. Behind, and on the outer side of the last molar, can be felt part of the back of the antrum and of the lower part of the external pterygoid plate.

On the roof of the mouth we can feel the pulsation of the posterior palatine artery. Hæmorrhage from this vessel can be arrested by plugging the orifice of the canal, which lies (not far from the surface) on the inner side of the last molar, about 1/3 of an inch in front of the hamular process.

When the mouth is wide open, the pterygo-maxillary ligament forms a prominent fold readily seen and felt beneath the mucous membrane, behind the last molar teeth. A little below the attachment of this ligament to the lower jaw we can easily feel the gustatory nerve, as it runs close to the bone below the last molar tooth. The exact position of the nerve can be ascertained in one’s own person by the acute pain on pressure. A division of the nerve, easily effected by a small incision, gives much temporary relief in cases of advanced carcinoma of the tongue.

To feed a patient in spasmodic closure of the jaw, it is well to know that there is behind the last molar teeth a space sufficient for the passage of a small tube into the mouth.

=Antrum.=--Lift up the upper lip and examine the front wall of the antrum. The proper place in which to tap it is above the second bicuspid tooth, about one inch above the margin of the gum.

20. =Posterior nares.=--A surgeon’s finger should be familiar with the feel of the posterior nares, and of all that is within reach behind the soft palate. This is important in relation to the attachment of polypi, to plugging the nostrils, and to the proper size of the plug. In the examination of this part of the back of the throat it is necessary to throw the head well back, because, in this position, nearly all the pharynx in front of the basilar process comes down below the level of the hard palate, and can be seen as well as felt. But when the skull is horizontal, i.e. at a right angle with the spine, the hard palate is on a level with the margin of the foramen magnum, and the parts covering the basilar process are concealed from view.

The head then being well back, introduce the forefinger behind the soft palate, and turn it up towards the base of the skull. You feel the strong grip of the superior constrictor. Hooking the finger well forwards, you can feel the contour of the posterior nares. Their size depends upon the anterior, but rarely exceeds a small inch in the vertical diameter, and a small half-inch in the transverse. The plug for the posterior nares should not be larger than this. Their plane is not perpendicular, but slopes a little forwards. You can feel the septum formed by the vomer, and also the posterior end of the inferior spongy bone in each nostril.

21. =Tonsils.=--Before taking leave of the throat, look well at the position of the tonsils between the anterior and posterior half arches of the palate. In a healthy state they should not project beyond the level of these arches. In all operations upon the tonsils, we should remember the close proximity of the internal carotid artery to their outer side. Nothing intervenes but the pharyngeal aponeurosis, and the superior constrictor of the pharynx. Hence the rule in operating on the tonsils, always to keep the point of the knife inwards.

In troublesome hæmorrhage from the tonsils, after an incision or removal, it is well to know that they are accessible to pressure if necessary by means of a padded stick, or even a finger.

22. =Features.=--A word or two on the lines of the face as indicative of expression. Everyone pays unconscious homage to the study of physiognomy when, scanning the features of a stranger, he draws conclusions concerning his intelligence, disposition, and character. Without discussing how much physiognomy is really worth, there can be no doubt that it is a mistake to place it in the same category as phrenology, since the latter lacks that sound basis of physiology which no one can deny to the former.

A person fond of observing cannot fail to have arrived at the conclusion that a man’s daily calling moulds his features. Place a soldier, a sailor, a compositor, and a clergyman side by side, and who will not immediately detect a marked difference in their physiognomies?

The muscles of the features are generally described as arising from the bony fabric of the face, and as inserted into the nose, the corners of the mouth, and the lips. But this description gives a very inadequate idea of their true insertion. They drop fibres into the skin all along their course, so that there is hardly a point of the face which has not its little fibre to move it. The habitual recurrence of good or evil thoughts, the indulgence in particular modes of life, call into play corresponding sets of muscles which, by producing folds and wrinkles, give a permanent cast to the features, and speak a language which all can understand, and which rarely misleads. Schiller puts this well when he says that ‘it is an admirable proof of infinite wisdom that what is noble and benevolent beautifies the human countenance; what is base and hateful imprints upon it a revolting expression.’

THE NECK.

23. =Subcutaneous veins.=--Notice first the direction of the subcutaneous veins. The chief subcutaneous vein is the external jugular. Its course corresponds with a line drawn from the angle of the jaw to the middle of the clavicle, where it joins the subclavian. It is made more prominent by putting the sterno-mastoid into action, or by gentle pressure on the lower end of the vein. It is exceptionally joined by a branch which runs over the clavicle, and is termed ‘jugulo-cephalic.’ The anterior jugular generally runs along the front border of the sterno-mastoid.

24. =Parts in central line. Os-hyoides.=--Immediately below and nearly on a level with the lower jaw we feel the body of the os-hyoides, and can trace backwards on each side the whole length of the cornua. They might easily be broken by the grasp of a garotter. Below the body of the os-hyoides is the gap above the thyroid cartilage. This gap corresponds with the anterior thyro-hyoid ligament and the apex of the epiglottis; so that in cases of cut throat in this situation, nearly the whole of the epiglottis lies above the wound.

=Thyroid cartilage.=--The projection and depth of the notch in the thyroid cartilage, or ‘pomum Adami,’ varies in different persons. Between the notch and the hyoid bone there is a large bursa, which facilitates the play of the cartilage beneath the bone in deglutition. The notch does not appear till puberty, and is throughout life much less distinct in the female than the male. The finger can trace the upper borders and cornua of the thyroid cartilage: its lower cornua can be felt by the side of the cricoid.

On each side of the thyroid cartilage we can recognise the lateral lobes of the thyroid gland. On the upper and front part of the gland we can distinctly feel the pulsation of the superior thyroid artery. This pulsation, coupled with the fact that the gland rises and falls with the larynx in deglutition, gives the best means of distinguishing a bronchocele from other tumours resembling it.

Below the angle of the thyroid cartilage we feel the interval between it and the cricoid, which is occupied by the cricothyroid membrane. In laryngotomy we cut through this membrane transversely close to the upper edge of the cricoid cartilage, in order that the incision may be as far as possible from the attachment of the vocal cords.