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166 CHAPTER 7: The Head and Neck
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FIG. 7-7 Lateral Nasal Wall. This parasagittal section shows the superior, middle, and inferior conchae; under each is its
corresponding meatus. Posterior to the inferior meatus is the orifice of the auditory (Eustachian) tube.
cells. The middle meatus receives drainage from the maxillary sinus, frontal
sinus, and anterior ethmoid cells. The inferior meatus contains the nasolacrimal
duct orice. The auditory (Eustachian) tube opens into the nasopharynx just
behind and lateral to the choana at the level of the middle meatus. The pharyngeal tonsils, or adenoids, are aggregations of lymphoid tissue in the poste-
rior nasopharynx.
Mouth and Oral Cavity: The mouth is surrounded by two eshy lips, their
vermillion borders marking transition from cornied epithelium to non-
cornied squamous epithelium in the mouth. The philtrum is a vertical groove
from the columella to vermilion border. The lips are closed and protruded by
contraction of the circular orbicularis oris muscle surrounding the mouth and
innervated by the facial nerve (CN-VII). Each lip is anchored to the gum by
a mucosal fold, the labial frenulum. A shallow vestibule separates the lips and
teeth. The oral cavity is a short tunnel with an arched roof formed by the hard
and soft palate. The hard palate, composed of maxilla and palatine bones covered by mucosa with a median raphe, is the roof’s anterior two-thirds. The soft
palate, a fold of mucosa and muscle, continues the roof posteriorly. The cheeks
and teeth form the walls and the tongue is the oor. The tunnel ends in the
isthmus faucium between the faucial pillars opening into the vertical oropharynx
continuous superiorly with the nasopharynx. The conical or bulbous uvula is
suspended from the free border of the soft palate. The lateral borders split into
two vertical folds, the tonsillar pillars. Between the anterior and posterior pillars lies the palatine tonsil, a mass of lymphoid tissue containing deep crypts or
clefts. Similar lymphoid tissue lies in the base of the tongue, the lingual tonsil.
Teeth. Upper and lower semicircles of teeth are set in the maxilla and mandi-
ble. The bony dental ridges and necks of the teeth are covered by tough brous
tissue and mucosa, the gums. The gum borders are called the gingival margins.
A child develops 20 deciduous teeth: from the upper and lower midline on
each side there are two incisors, one canine, and a rst and second molar. These
teeth are gradually lost and replaced by permanent teeth adding a rst and second premolar, or bicuspid, and a third molar making a total of 32 (Table 7-1).
Dentists use a universal numbering system starting with the right upper third
molar as 1 and counting left to the opposite upper third molar as 16, then
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TABLE 7-1 Age at Tooth Eruption
Deciduous (mo) Permanent (y)
First molars 15–21 6
Central incisors 6–9 7
Lateral incisors 15–21 8
First premolars 9
Second premolars 10
Canines 16–20 12
Second molars 20–24 12–13
Third molars 17–25
continuing down to the left lower third molar as 17 and counting right to 32
at the mandibular third molar. The eruption times of the various teeth are
shown in Table 7-1.
Tongue. The tongue lies within the mandible’s horseshoe curve, its dorsal sur-
face forming the oor of the oral cavity. The thin and narrow tip rests against
the lingual surface of the lower incisors. The posterior and inferior root is
composed of muscles and their bony attachments. The tip and dorsal surface
are visible portions of a much larger muscular mass. Contracting the extrin-
sic muscles connecting the symphysis mentis of the mandible, hyoid bone, and
styloid process of the temporal bone causes protrusion and retraction of the
tip, convex and concave curving of the dorsum, and moves the root upward
and downward. The intrinsic muscles alter the length, width, and curvature
of the dorsal surface. The lingual muscles are innervated by the hypoglossal
nerve (CN-XII). The tongue is free at its tip, dorsum, sides, and anteroinferior
surface (Fig. 7-8). A midline fold of mucosa, the lingual frenulum, attaches the
tongue to the oor of the mouth and the lingual surface of the lower gum.
Near its base the frenulum swells forming twin eminences, the carunculae sub-
lingualis, each containing the orice of a submandibular duct (Wharton duct).
Running from the carunculae laterally and posteriorly around the tongue
base is a ridge of mucosa, the plica sublingualis, punctured at intervals by duct
orices from the sublingual gland lying deep to the ridges. The dorsum of the
tongue extends from its tip to the epiglottis. It is bisected by the median sul-
cus from the tip to the posterior third, ending in a depression, the foramen
cecum, marking the orice of the embryonic thyroglossal duct prior to closure.
A sulcus terminalis extends forward and laterally from either side of the fora-
men cecum forming a V. Slightly anterior and parallel is another V formed
by 8-12 discrete round eminences with concentric fossae, the vallate papil-
lae. The dorsum’s anterior two-thirds has a velvet texture from microscopic
liform papillae which catch desquamated cells, bacteria, and food particles.
Scattered among the liform papillae at the tip and sides are less numerous
large, raised, rounded, and deeper red fungiform papillae. Microscopic taste
buds are numerous in vallate and fungiform papillae, on the tongue’s sides
and back, in the soft palate, and on the posterior surface of the epiglottis.
The sensory root of the facial nerve (CN-VII) supplies the taste buds in the
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FIG. 7-8 Tongue Surfaces. A. The dorsal surface from the tip of the epiglottis is depicted, showing the position of
the palatine tonsils. B. The ventral surface is viewed from the outside of the mouth. The caruncula sublingualis is at the
base of the frenulum; it contains the orifices of the submaxillary salivary ducts. In the plica sublingualis are some sublingual
salivary gland orifices.
anterior two-thirds of the tongue via the chorda tympani. The posterior third is
innervated by the glossopharyngeal nerve (CN-IX).
Larynx: The larynx lies immediately behind and below the oral cavity. The
tip of the epiglottis is often visible through the mouth. Because the larynx
is on the anterior wall of the pharynx with the plane of its rim sloping posteriorly it is easily viewed using a laryngeal mirror (Fig. 7-9). Visualize the
laryngeal apparatus as three stacked incomplete rings, one atop the other,
held together by ligaments. Topmost is the arched hyoid bone opening posteriorly. Suspended below are the arched thyroid cartilage, also opening posteriorly, and the cricoid cartilage, a complete ring xed to the tracheal rings below.
Though these structures are practically subcutaneous and easily palpable in
the neck, their openings are posterior and well protected.
Phonation depends on the shape, position, and movement of two ary-
tenoid cartilages (Fig. 7-10), each a three-sided pyramid with a triangular
slightly concave base. The cricoarytenoid joint, a synovial joint surrounded
by a capsule, allows the arytenoids to glide on the convex surface of the
cricoid’s posterior rim. The two erect pyramids stand on either side of the
cricoid’s midline. Muscles pull on the pyramid’s faces rotating their bases
at the joints. Each pyramid’s apex is surmounted by a horizontal crescent
of small cartilages and ligaments pointing medially toward its opposite and
curving anteriorly. From the curve of each crescent, a tough broelastic band,
the true vocal cord (vocal fold), extends forward to the midline of the thyroid cartilage. The two vocal cords form the opening into the trachea, the
rima glottidis. When open, the rima is an isosceles triangle, with apex anterior, beneath the epiglottis and base posterior, formed by the tissue bridge
between the two arytenoid crescents. As the arytenoids rotate the triangle’s
legs come together posteriorly approximating the cords over their entire
length and closing the airway. Above the true cords is a pair of tissue folds,
the false vocal cords (ventricular folds). A membrane covering the epiglottis
and continuing posteriorly to envelope the arytenoids forms the aryepiglottic
folds. The protrusion of the larynx from the anterior pharyngeal wall forms
A. Mirror laryngoscopy B. Mirrored appearance of larynx
Functional Anatomy of the Head and Neck 169
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Aryepiglottic
fold
False
cord
epiglottidis
Vallecula
Rima
Arytenoid
cartilage
POSTERIOR
Median
glossopharyngeal
fold
Tubercle of
epiglottis
True
left
cord
FIG. 7-9 Mirror Laryngoscopy. A. Hand and instrument position for laryngoscopy. B. Appearance of
the larynx in the mirror. This is the appearance with the cords abducted.
FIG. 7-10 Anatomy of the Larynx. T he larynx faces posteriorly; i t is seen with the mirror behind the plane of the vocal
cords. T he arytenoi d cartilages are small py ramids perched on the cricoid cartilage, to wh ich they are connected by true joint s.
The arytenoid cartilages twist on their bases to vary vocal cord tension.
pockets, two valleculae between the epiglottis and tongue base and two piriform sinuses, one on either side of the cricoid. The intrinsic muscles of the
larynx are largely innervated by the recurrent laryngeal nerve, a branch of the
vagus nerve (CN-X).
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FIG. 7-11 Anatomic Relations of the Salivary Glands to the Mandible. Note that the parotid gland lies on the
later al surface of t he mandibula r ramus, curlin g behind its po sterior marg in. The submax illary glan d is on the medial s urface of
the mandible with its lower margin protruding below the bone. The sublingual gland is behind the medial mandibular surface
near its superior margin. Using the jaw for a landmark, the glands can be accurately located by palpation.
The Salivary Glands
Parotid glands. To recognize parotid enlargement, its location and extent
must be known (Fig. 7-11). The largest salivary gland, the normal parotid
is not palpable as a distinct structure. A subcutaneously supercial portion
extends from the zygomatic arch superiorly to the angle of the mandible inferiorly and from the external auditory canal posteriorly to the midportion of
the masseter muscle anteriorly. The tail wraps around the angle and horizontal ramus of the mandible, and a deep lobe extends from the tail medially
to the stylomandibular ligament and styloid muscles. The 5 cm long parotid
(Stensen) duct runs forward horizontally on the masseter muscle approximately one ngerbreadth below the zygomatic arch. It lies on a line from the
inferior border of the concha to the commissure of the lips. At the masseter’s
anterior border it pierces the buccinator muscle to reach its orice in a papilla
on the buccal mucosa opposite the upper second molar.
Submandibular glands. Approximately the size of a walnut, the gland lies
medial to the inner surface of the mandible. Its lower portion is palpated
beneath the inferior mandibular border somewhat anterior to the angle of the
jaw. The submandibular (Wharton) duct is about 5 cm long running upward and
forward to the oor of the mouth where its orice is crowned by the caruncula
sublingualis beside the lingual frenulum.
Sublingual glands. The smallest of the glands, it lies beneath the oor of the
mouth, near the symphysis mentis. It empties through several short ducts, some
with orices in the plica sublingualis, some entering the submandibular duct.
The Thyroid Gland: Knowledge of thyroid embryology is necessary for
understanding thyroid disorders. A median diverticulum invaginating from
the ventral pharyngeal wall (the future foramen cecum in the tongue), goes
down and back anterior to the trachea as a tubular duct, the thyroglossal
duct. It bifurcates and further divides into cords that later fuse forming the
Hyoid bone
Thyroid cartilage
Course of thyroglossal duct
Right lobe of thyroid gland
Tracheal rings
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Foramen cecum
Sternohyoideus m.
Sternocleidomastoideus m.
FIG. 7-12 Anatomic Relations of the Thyroid Gland, Anterior View. The blue structures are the thyroid gland
and the course of the obliterated thyroglossal duct.
thyroid isthmus and lateral lobes. Normally, the thyroglossal duct is obliterated but remnants may persist forming thyroglossal sinuses or cysts. At the
duct’s superior end, a normally functioning lingual thyroid gland may form.
Inferiorly, ductal tissue frequently forms a pyramidal lobe arising from the isthmus or a lateral lobe, usually the left. The pyramidal lobe may ascend anterior
to the thyroid cartilage as high as the hyoid bone. Occasionally, the isthmus or
a lateral lobe may fail to develop. Rarely, a lingual thyroid is the only active
thyroid tissue.
The thyroid is the largest endocrine gland. It consists of two lateral lobes
whose upper halves lie on either side of the projecting prow of the thyroid
cartilage. The lower halves are beside the trachea (Fig. 7-12). The isthmus
passes in front of the upper tracheal rings joining the lateral lobes at their
lower thirds. The gland is roughly trapezoidal, the top and bottom parallel
and the sides converging downward. The normal adult gland weighs
~25–30 g slightly larger in females than males. Each lateral lobe is an
irregular cone ~5 cm long, ~3 cm wide, and ~2 cm thick. The right lobe is
usually one-fourth larger than the left. The lateral posterior borders touch the
common carotid arteries. Usually, the parathyroid glands lie on the posterior
lateral surfaces. The recurrent laryngeal nerves lie close to the medial deep surface. Each lobe is covered anteriorly by the respective sternocleidomastoid,
whereas the isthmus lying on the tracheal rings is practically subcutaneous.
Paired superior and inferior thyroid arteries supply the exceedingly vascular
parenchyma. The gland is rmly xed to the trachea and larynx, ascending
with them during swallowing, distinguishing the thyroid from other neck
masses. Consider the thyroid as part of the upper anterior mediastinum.
Enlargement downward extends behind the sternum, a retrosternal goiter.
The thymus gland also occupies the anterior mediastinum. Thus, a tumor of
the anterior mediastinum can arise from either gland.
Examining the Scalp, Face, and Skull: Examine by inspection and palpation.
Inspect for asymmetry of the skull, ears, eyes, nose, mouth, jaw, and cheeks.
PHYSICAL EXAMINATION OF THE HEAD AND NECK
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Aligning a tongue blade from the glabella’s midline to the midline of the lips
reveals nasal and facial deformity. Observe ear position from the front. Inspect
the scalp by displacing the hair sequentially revealing the roots. Inspect for
actinic changes and lesions on sun-exposed skin, especially the helix of the
ear, temples above the zygoma, forehead, cheeks, and lips. Gently palpate
the skull for irregularities. Run a ngertip around the orbital rim and along
the zygoma on each side. Palpate the ramus, angle, and arch of the mandible.
Examining the Ears, Hearing, and Labyrinth Function
Ears
Pinna. Inspect the pinna for size, shape, and color. Note discharge from the
meatus. Palpate the consistency of the cartilages and any swellings. Assess for
pain with movement of the pinna and tragus.
External acoustic meatus. Clean the canal for inspection. Remove liquid material with a cotton applicator. Remove solids under direct vision through an
ear speculum with either a cotton applicator or a cerumen spoon. Use a speculum attached to an otoscope or a speculum and a headlamp. Select the largest
speculum that will t the cartilaginous canal. Tip the head toward the opposite shoulder making the canal horizontal. Insert the speculum while retracting the pinna up and back aligning the exible cartilaginous canal with the
bony canal. Use downward traction for infants and young children (Fig. 7-13).
The lining epithelium of the bony canal is very sensitive, so be gentle.
TM and middle ear. Light shining on the TM reects a brilliant wedge of light,
the light reex, whose apex is at the center or umbo with its legs extending
radially in the anterior inferior quadrant of the TM, at approximately a right
angle to the manubrium. Examine the normal landmarks of the drumhead.
The manubrium of the malleus forms a smooth ridge from the umbo running
radially upward and forward ending in the knob of the short process. The two
mallear folds diverge from the knob to the periphery. The shadow of the incus
often shows through the membrane in the upper posterior quadrant. Finally
inspect the entire circumference of the annulus for perforations just inside
its border. Note the color and sheen of the membrane, which should be shiny
and pearly gray. Serum in the middle ear colors the TM amber or yellow
FIG. 7-13 Use of the Otoscope. Insert the ear speculum by pulling the upper edge of the pinna upward and backward
to straighten the cartilaginous meatus so that it coincides with the axis of the bony canal.
A. Weber test B. Rinne test
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and air bubbles may be seen. Pus shows as a chalky white membrane and
blood appears blue. Note changes in the denition of the manubrium. When the
TM bulges it makes the landmarks indistinct or obscures them completely.
Inadequate auditory (Eustachian) tube function produces TM retraction
sharpening the outline of the manubrium and mallear folds. With either
bulging or retraction the light reex is distorted or absent. When the incus is
visible, the middle ear is normal.
Testing hearing. Rough quantitative test for hearing loss. Difculty understand-
ing spoken questions signals potential hearing loss. Test with the whispered
voice at the patient’s side ~ 60 cm (2 ft) from each ear while covering the
far ear. The patient repeats whispered numbers, or questions that cannot be
answered yes or no. Test with loud, medium, and soft tones. Alternatively,
using the same intensity for all tests, nd the maximum distance at which
the whisper is understood. Hearing acuity is tested with a 256 or 1024 cycles
per second tuning fork. The 128-cycle fork for testing vibratory sense is too
low pitched.
Distinguishing neurosensory and conductive hearing loss. Use a tuning fork having a frequency of 256 or 1024 cycles per second. Tap the fork on the base of
the other hand. The
Weber test (Fig. 7-14A) places the handle of the vibrating
fork against the skull’s midline asking whether the sound is louder in one
ear than the other. With normal neurosensory hearing and no conductive
loss the sounds are equal in both ears. The Rinne test (Fig. 7-14B) is done
in each ear sequentially. First, press the vibrating tuning fork against the
mastoid process (bone conduction) and then place the tines near the ear canal
(air conduction). Ask which is louder. When air conduction is louder than
bone conduction, the test is arbitrarily said to be Rinne-positive, a normal
result. The test is Rinne-negative when bone conduction is louder than air
conduction. Have the patient indicate when the sound is no longer heard
by air conduction. See if you can hear the vibrating fork to compare their
hearing to yours.
Testing vestibular function. The Dix–Hallpike maneuver for positional vertigo.
With the patient sitting on the exam table, inspect the eyes carefully for
FIG. 7-14 Tests of Hearing Perception and Conduction. A. Weber test: The vibrating tuning fork is on the
midline of the skull. Lateralization of the sound to one ear indicates a conductive loss on that side, or a perceptive loss on the
other side. B. Rinne test: T he handle of t he tuning for k is first place d against the m astoid proce ss then near t he external e ar.
Each time the patient indicates when the sound ceases. Normally, duration of air conduction is twice that of bone conduction.
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spontaneous nystagmus. Then, keeping the eyes open, have the patient lie
supine with the head extending beyond the end of the table, the chin elevated
~30 degrees and the head turned 45 degrees to the right. Observe the eyes
for 30 seconds looking for nystagmus. Return the patient to the sitting position inspecting the eyes for another 30 seconds. Repeat the test with the head
turning to the left. A positive test induces nystagmus, often accompanied by
intense nausea. The slow component of the nystagmus is in the direction of
endolymph ow; nystagmus is named for its fast component.
Test for Past Pointing. The patient sits with her eyes closed while pointing her
forengers toward the examiner (Fig. 7-15). The examiner’s forengers are
lightly placed and held under hers. Ask the patient to raise her arms and
hands and then return them to the starting position. Normally, this maneuver
can be performed accurately. Past pointing indicates either loss of positional
sense or labyrinth stimulation.
Romberg Test. The patient stands with heels and toes close together (Fig. 7-16).
Assure the patient that you will not let her fall, being prepared to catch her
should she fall. Have her close her eyes and observe for several seconds.
FIG. 7-15 Past Pointing Test for Labyrinthine Disorders.
FIG. 7-16 Falling Test for Labyrinthine Disorders (Romberg Sign). Normally, the patient will waver somewhat,
but not fall. With labyrinthine stimulation, the patient tends to fall in the direction of the flow of endolymph. Falling may also
indicate loss of positional sense as in cerebellar deficits.
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Normally, patients will be steady, even with gentle, forewarned, pushes on
the trunk. Falling during the test means the Romberg sign is present.
Examining the Eyes, Visual Fields, and Visual Acuity
Palpebral ssures and globe position. From a distance, note the width and symmetry of the palpebral ssures. Look for protrusion or recession of one or both
globes by inspecting the eyes from the front, prole, and above (looking downward over the forehead), or from below (looking up over the cheekbones). If
proptosis (protrusion) is suspected, use a Hertel exophthalmometer to measure
the distance from the outer edge of the bony orbit to the anterior surface of the
cornea. There are familial and racial degrees of proptosis, and individual variation is great. Progressive anterior displacement on repeated exams is pathologic.
Inspecting for inammation. Inspect for redness and/or swelling and
involvement of one or both eyes and/or eyelids.
Testing for lid lag, lid retraction, and scleral show. Use a nger or penlight
as a target ~50 cm (20 inch) away. Starting above eye level, repeatedly move
the target slowly up and down in the midline (Fig. 7-17). Lid-lag is present
when white sclera appears between the lid margin and limbus. Lid retraction is dynamic upper lid elevation while xing gaze on a spot. Scleral show
is more constant exposure of the sclera. The inferior sclera shows below the
limbus in some normal individuals.
Testing for Strabismus (Heterotropia). First conrm functional vision in
each eye.
Cover–uncover test. With the gaze xed on a target, cover one eye while
watching the uncovered eye (Fig. 7-18) seeing if it moves to take up xation. Allow the patient to look with both eyes, then cover the other eye again
watching the uncovered eye seeing if it moves to xation. If there is xation
movement, the patient has heterotropia (strabismus, squint). Constant misalignment of this type is manifest deviation or tropia.
Alternate cover test. While the patient holds visual xation, repeatedly cover
one eye then the other. If there was not a manifest deviation by cover-uncover
testing, but now, when uncovered, each eye moves to pick up xation, latent
FIG. 7-17 Test for Lid Lag.
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