The palate pdf - Head and neck

626

CHAPTER 11

The Head and Neck

The anterior two thirds of the tongue is separated from the

soft palate.

foramen. The glossopharyngeal nerve also supplies the

enters the front of the hard palate through the incisive

nasopalatine nerve, also a branch of the maxillary nerve,

the greater and lesser palatine foramina (Fig. 11.74). The

division of the trigeminal nerve enter the palate through

The greater and lesser palatine nerves from the maxillary

Nerve Supply of the Palate

nerve supply, and actions are summarized in Table 11.9.

The muscles of the soft palate, their origins, insertions,

a tense sheet.

that the soft palate may be moved upward or downward as

cles of the two sides contract, the soft palate is tightened so

expands to form the palatine aponeurosis. When the mus

The tendon, together with the tendon of the opposite side,

don, which turns medially around the pterygoid hamulus.

as they descend from their origin to form a narrow ten

The muscle fibers of the tensor veli palatini converge

nerve as it passes downward and forward in the carotid tri

ing hindbrain and later migrate inferiorly and anteriorly around

the mucous membrane just anterior to the sulcus terminalis,

of the tongue becomes free. Some of the entodermal cells remain

lying mesenchyme. Later, these cells degenerate so that this part

arches. Around the edge of the anterior two thirds of the tongue,

ryngeal arches and the anterior ends of the third pharyngeal

posterior third by a groove, the sulcus terminalis, which repre-

sents the interval between the lingual swellings of the first pha-

the entodermal cells proliferate and grow inferiorly into the under-

in the midline and help form the frenulum of the tongue.

Remember that the circumvallate papillae are situated on

and that their taste buds are innervated by the ninth cranial

nerve. It is presumed that during development the mucous

membrane of the posterior third of the tongue becomes pulled

anteriorly slightly, so that fibers of the ninth cranial nerve cross

the succus terminalis to supply these taste buds (Fig. 11.79).

The muscles of the tongue are derived from the occipital

myotomes, which at first are closely related to the develop-

the pharynx and enter the tongue. The migrating myotomes

carry with them their innervation, the 12th cranial nerve, and

this explains the long curving course taken by the 12th cranial

angle of the neck (see page 616).

right hypoglossal nerve

cut right hypoglossal
nerve

intact
hypoglossal
nerve

right half
of tongue
atrophied

genioglossus muscle

FIGURE 11.78

Diagrammatic representation of the action of

geus, and the musculus uvulae (Fig. 11.81).

levator veli palatini, the palatoglossus, the palatopharyn

The muscles of the soft palate are the tensor veli palatini, the

Muscles of the Soft Palate

don of the tensor veli palatini muscle.

posterior border of the hard palate. It is the expanded ten

The palatine aponeurosis is a fibrous sheet attached to the

Palatine Aponeurosis

faces of the soft palate.

The mucous membrane covers the upper and lower sur

Mucous Membrane

tine aponeurosis, and muscles.

The soft palate is composed of mucous membrane, pala

lateral wall of the pharynx.

The soft palate is continuous at the sides with the

uvula.

der presents in the midline a conical projection called the

border of the hard palate (Fig. 11.81). Its free posterior bor

The soft palate is a mobile fold attached to the posterior

(Fig. 11.80). It is continuous behind with the soft palate.

maxillae and the horizontal plates of the palatine bones

The hard palate is formed by the palatine processes of the

front and the soft palate behind.

nasal cavity. It is divided into two parts: the hard palate in

The palate forms the roof of the mouth and the floor of the

The origin and insertion and direction of

the nerve lesion.

asked to protrude the tongue, the tip points to the side of

When the patient is

The right hypoglossal nerve (which innervates

the tip of the tongue is protruded in the

The right and left muscles contract equally together

the right and left genioglossus muscles of the tongue.

and as a result (B)

midline. C.

the genioglossus muscle and the intrinsic tongue muscles

on the same side) is cut and as a result the right side of the

tongue is atrophied and wrinkled. D.

pull of the genioglossus muscle.

The Palate

Hard Palate

Soft Palate

Basic Anatomy

627

tuberculum impar

lingual swelling

of first pharyngeal

arch

copula

laryngotracheal

groove

endodermal

lining of pharynx

tuberculum impar

lingual swelling

of first pharyngeal

arch

copula

laryngotracheal

groove

developing

epiglottis

developing

epiglottis

foramen cecum

posterior

third of
tongue

anterior two thirds

of tongue

circumvallate papillae

sulcus terminalis

FIGURE 11.79

The floor of the pharynx showing the stages in the development of the tongue.

the palatoglossal and palatopharyngeal arches (Fig. 11.81).

which are masses of lymphoid tissue, are located between

palatine tonsils,

The

palatopharyngeus muscle.

fold is the

join the pharyngeal wall. The muscle contained within the

(Figs. 11.72 and 11.81) that runs downward and laterally to

fold of mucous membrane behind the palatoglossal arch

The palatopharyngeal arch is a

Palatopharyngeal Arch

where the mouth becomes the pharynx.

The palatoglossal arch marks

(Figs. 11.72 and 11.81).

which extends from the soft palate to the side of the tongue

palatoglossus muscle,

mucous membrane containing the

The palatoglossal arch is a fold of

Palatoglossal Arch

Deep Cervical Lymph Nodes

Lymph Drainage of the Palate

ascending pharyngeal artery

ascending palatine branch of the facial artery, and the

The greater palatine branch of the maxillary artery, the

Blood Supply of the Palate

628

CHAPTER 11

The Head and Neck

maxillary artery

mandibular nerve

middle meningeal
artery
tensor veli palatini

levator veli palatini

auditory tube

superior constrictor

stylopharyngeus

stylohyoid ligament

superior laryngeal nerve

internal laryngeal nerve

external laryngeal nerve

inferior constrictor

recurrent laryngeal nerve

esophagus

trachea

cricothyroid muscle

thyrohyoid membrane

middle constrictor

mylohyoid

buccinator

incisive fossa

palatine
process
of maxilla

horizontal
plate of
palatine
bone

hard

palate

pterygomandibular ligament

FIGURE 11.80

off from the oral part.

tains. By this means, the nasal part of the pharynx is closed

palatopharyngeal arches are pulled medially, like side cur

geus muscles on both sides also contract so that the

the posterior pharyngeal wall forward. The palatopharyn

fibers of the superior constrictor muscle contract and pull

tor veli palatini on each side. At the same time, the upper

The soft palate is raised by the contraction of the leva

duction of explosive consonants in speech.

by raising the soft palate. Closure occurs during the pro

between the nasal and oral parts of the pharynx) is closed

The pharyngeal isthmus (the communicating channel

Movements of the Soft Palate

Three constrictor muscles of the pharynx. The superior and recurrent laryngeal nerves are also shown.

B. Hard palate.

Angioedema of the Uvula (Quincke’s Uvula)

lae, that is attached to the posterior border of the hard palate.

The uvula has a core of voluntary muscle, the musculus uvu-

Surrounding the muscle is the loose connective tissue of the

submucosa that is responsible for the great swelling of this

structure secondary to angioedema.

C L I N I C A L N O T E S

Development of the Palate

fusion takes place from the anterior to the posterior region. The

In early fetal life, the nasal and mouth cavities are in commu-

nication, but later they become separated by the development

of the palate (Fig. 11.82). The primary palate, which carries

the four incisor teeth, is formed by the medial nasal process.

Posterior to the primary palate, the maxillary process on each

side sends medially a horizontal plate called the palatal process;

these plates fuse to form the secondary palate and also unite

with the primary palate and the developing nasal septum. The

primary and secondary palates later will form the hard palate.

Two folds grow posteriorly from the posterior edge of the palatal

processes to create the soft palate, so that the uvula is the last

structure to be formed (Fig. 11.82). The union of the two folds of

E M B R Y O L O G I C N O T E S

(continued)

Basic Anatomy

629

middle concha

palate

tongue

palatoglossal fold

vallecula

entrance to larynx

palatopharyngeal

fold

tonsil

uvula

superior

constrictor

sphenoid sinus

pharyngeal recess

salpingopharyngeal fold

tubal elevation

tensor veli palatini

auditory tube

levator veli palatini

salpingopharyngeus

superior

constrictor
soft palate

palatopharyngeus

middle constrictor

mucous membrane

epiglottis

palatoglossus

vallecula

nasal septum

middle concha

levator veli palatini

tensor veli

palatini

hamulus

musculus uvulae

uvula

palatopharyngeus

carotid sheath

internal carotid artery

facial artery

tonsillar

artery

external palatine

vein

ramus of mandible

vestibule of mouth

buccinator

lip

pterygomandibular

ligament

palatoglossus

tonsillar crypts

capsule of tonsil

palatopharyngeus

pharyngeal raphe

superior constrictor

auditory

tube

FIGURE 11.81

pharynx showing the relations of the tonsil.

Horizontal section through the mouth and the oral part of the

Muscles of the soft palate seen from behind.

pharynx.

Muscles of the soft palate and the upper part of the

Note the position of the tonsil and the opening of the auditory tube.

Junction of the nose with the nasal part of the pharynx and the mouth with the oral part of the pharynx.

the soft palate occurs during the eighth week. The two parts of

Plastic surgery is recommended usually between 1 and 2 years

regurgitated through the nose or aspirated into the lungs, leading

feeding problem, since he or she is unable to suck efficiently.

A baby born with a severe cleft palate presents a difficult

a bilateral cleft lip and failure of the primary palate to fuse with

associated with bilateral cleft lip. A rare form may occur in which

and a cleft on both sides of the primary palate. This type is usually

of severity, which is rare, consists of ununited palatal processes

is usually associated with unilateral cleft lip. The fourth degree

processes and a cleft on one side of the primary palate. This type

ununited palatal processes. The third degree is ununited palatal

first degree of severity is cleft uvula, and the second degree is

the primary palate (premaxilla) (Figs. 11.83 and 11.84). The

midline; in severe cases, these processes also fail to fuse with

palatal processes of the maxilla to fuse with each other in the

degrees of cleft palate occur and are caused by failure of the

Cleft palate is commonly associated with cleft upper lip. All

the uvula fuse in the midline during the 11th week. The interval

between the primary palate and secondary palate is represented

in the midline by the incisive foramen.

Cleft Palate

the palatal processes of the maxilla on each side are present.

Such a baby often receives in the mouth some milk, which then is

to respiratory infection. For this reason, careful artificial feeding

is required until the baby is strong enough to undergo surgery.

of age, before improper speech habits have been acquired.

630

CHAPTER 11

The Head and Neck

Muscles of the Soft Palate

T A B L E 1 1 . 9

Tenses soft palate

Tensor veli palatini

Muscle

Origin

Insertion

Nerve Supply

Action

Spine of sphenoid,

auditory tube

With muscle of other

side, forms palatine

aponeurosis

Nerve to medial pterygoid

from mandibular nerve

Levator veli palatini

Petrous part of temporal

bone, auditory tube

Palatine aponeurosis

Pharyngeal plexus

Raises soft palate

Palatoglossus

Palatine aponeurosis

Side of tongue

Pharyngeal plexus

Pulls root of tongue

upward and backward,

narrows oropharyngeal

isthmus

Palatopharyngeus

Palatine aponeurosis

Posterior border of

thyroid cartilage

Pharyngeal plexus

Elevates wall of pharynx,

pulls palatopharyngeal

folds medially

Musculus uvulae

Posterior border of hard

palate

Mucous membrane of

uvula

Pharyngeal plexus

Elevates uvula

communication

between nasal

and mouth

cavities

palatal process

of maxilla

superior concha

middle
concha

inferior
concha

tongue

nasal

cavity

palatal process

of maxilla

mouth

cavity

nasal
cavity

mouth
cavity

primary

palate

palatal
processes
of the
maxilla

nasal septum

primary

palate

primary palate

formation of

secondary palate

incisive

foramen

future

hard

palate

soft
palate

uvula

nasal septum

FIGURE 11.82

molar tooth (Fig. 11.72).

the mouth upon a small papilla opposite the upper second

the lateral surface of the masseter. It enters the vestibule of

the anterior border of the gland and passes forward over

The parotid duct emerges from

deep lobes.

superficial

mastoid muscle. The facial nerve divides the gland into

mandible (Fig. 11.85), and in front of the sternocleido

the external auditory meatus, behind the ramus of the

posed mostly of serous acini. It lies in a deep hollow below

The parotid gland is the largest salivary gland and is com

The different stages in the formation

The formation of the palate and the nasal septum (coronal section). B.

of the palate.

The Salivary Glands

Parotid Gland

and