The respiratory system in the head and neck pdf - Head and Neck

Basic Anatomy

639

superior, middle, and inferior constrictor muscles. Some of

(Fig. 11.90). The capsule is separated from the supe

capsule

fibrous

The tonsil is covered on its lateral surface by a

tonsillar crypts.

openings that lead into the

into the pharynx. The surface is pitted by numerous small

by mucous membrane, and its free medial surface projects

palatopharyngeal arches (Fig. 11.90). Each tonsil is covered

oral part of the pharynx between the palatoglossal and

each located in the depression on the lateral wall of the

The palatine tonsils are two masses of lymphoid tissue,

Palatine Tonsils

geus muscle) relaxes and the bolus enters the esophagus.

Finally, the lower part of the pharyngeal wall (the cricopharyn

piriform fossae.

into the larynx, that is, down through the

the food slides down the groove on either side of the entrance

rior constrictor muscle by loose areolar tissue (Fig. 11.90),

the respiratory and digestive systems forms a ring. The

The lymphoid tissue that surrounds the opening into

Waldeyer’s Ring of Lymphoid Tissue

behind the angle of the mandible.

The upper deep cervical lymph nodes, just below and

Lymph Drainage of the Tonsil

tine, the pharyngeal, or the facial veins.

the superior constrictor muscle and join the external pala

The tonsillar branch of the facial artery. The veins pierce

hood, but after puberty it diminishes considerably in size.

The tonsil reaches its maximum size during early child

the loop of the facial artery, and the internal carotid artery.

the superior constrictor muscle lie the styloglossus muscle,

in this tissue to join the pharyngeal venous plexus. Lateral to

and the external palatine vein descends from the soft palate

Blood Supply

lateral part of the ring is formed by the palatine tonsils
and tubal tonsils (lymphoid tissue around the opening
of the auditory tube in the lateral wall of the nasopharynx).

Posteriorly:

chea and the esophagus (Fig. 11.49).

ascend one on each side, in the groove between the tra

The trachea; the recurrent laryngeal nerves

Anteriorly:

rax is described on page 100.

neck, it inclines to the left side. Its further course in the tho

commences in the midline, but as it descends through the

tilage, opposite the body of the sixth cervical vertebra. It

11.13 and 11.88). It begins at the level of the cricoid car

long, extending from the pharynx to the stomach (Figs.

The esophagus is a muscular tube about 10 in. (25 cm)

of the tongue forms the lower part.

the upper part, and the lingual tonsil on the posterior third

The pharyngeal tonsil in the roof of the nasopharynx forms

The Esophagus

Relations in the Neck

■

The prevertebral layer of deep

ical

cerv

fascia, the longus colli, and the vertebral column
(Fig. 11.49)

is the area of the nasal cavity lying just inside the nostril

nasal vestibule

nose opens into the nasopharynx. The

behind, where the

choanae

posterior nasal apertures

The nasal cavity extends from the nostrils in front to the

Nasal Cavity

maxillary nerve (CN V) (see page 608).

thalmic nerve (CN V) and the infraorbital branch of the

The infratrochlear and external nasal branches of the oph

plied by branches from the facial artery.

skin of the ala and the lower part of the septum are sup

ophthalmic and the maxillary arteries (see page 598). The

The skin of the external nose is supplied by branches of the

formed of plates of hyaline cartilage (Fig. 11.92).

the nasal part of the frontal bone. Below, the framework is

the nasal bones, the frontal processes of the maxillae, and

The framework of the external nose is made up above by

rounded and mobile.

(Fig. 11.92). The lateral margin, the

septum

which are separated from each other by the

trils,

The external nose has two elliptical orifices called the

External Nose

halves.

both of which are divided by a septum into right and left

The nose consists of the external nose and the nasal cavity,

and from the sympathetic trunks.

The nerves are derived from the recurrent laryngeal nerves

The lymph vessels drain into the deep cervical lymph nodes.

Lymph Drainage in the Neck

rior thyroid veins.

drain into the infe

veins

the inferior thyroid arteries. The

of the esophagus in the neck are derived from

arteries

The

and the carotid sheath (Fig. 11.49)

On each side lie the lobe of the thyroid gland

Laterally:

■

Blood Supply in the Neck

Nerve Supply in the Neck

The Respiratory System in the Head

and Neck

The Nose

nos-

nasal

ala nasi, is

Blood Supply of the External Nose

Nerve Supply of the External Nose

(Fig. 11.93). The nasal cavity is divided into right and left

and a medial or septal wall.

Each half of the nasal cavity has a floor, a roof, a lateral wall,

Walls of the Nasal Cavity

vomer.

ethmoid,

vertical plate of the

septal cartilage,

made up of the

(Fig. 11.92). The septum is

nasal septum

halves by the

the

and the

640

CHAPTER 11

The Head and Neck

frontal bone

nasal bone

nasal
bone

nasal bone frontal process

of maxilla

maxilla

incisive canal

vomer

sphenoid sinus

horizontal plate

of palatine

palatine process of maxilla

vertical plate

of ethmoid bone

frontal

sinus

upper lateral
nasal cartilage

upper lateral
nasal cartilage
septal cartilage

septal
cartilage

lesser alar cartilages

nostril

lower lateral
nasal cartilage

accessory cartilage

FIGURE 11.92

External nose and nasal septum.

Bony and cartilaginous skeleton of nasal septum.

rior view of bony and cartilaginous skeleton of external nose.

Lateral view of bony and cartilaginous skeleton of external nose.

B. Ante-

frontal

sinus

cribriform plate of ethmoid

sphenoethmoidal recess

sphenoidal sinus

sphenoidal air sinus

openings of

posterior

ethmoidal

sinuses

openings of middle

ethmoidal sinuses

openings of auditory

tube

openings of

maxillary sinus

body of sphenoid bone

superior nasal concha

middle nasal concha

middle nasal

concha

inferior nasa

concha

inferior nasal concha

inferior meatus

opening of

nasolacrimal duct

soft palate

hard palate formed by

palatine process of maxilla and

horizontal plate of palatine bone

middle meatus

hiatus semilunaris

superior meatus

nasal bone

atrium of

middle

meatus

vestibule

nostril

bony channel by

which frontal

sinus opens into

infundibulum

opening of frontal

sinus into

infundibulum

opening of anterior

ethmoidal sinuses

bulla ethmoidalis

FIGURE 11.93

posterior ethmoid sinuses.

superior concha (Fig. 11.93). It receives the openings of the

The superior meatus lies below the

Superior Meatus

(Fig. 11.93).

sphenoid air sinus

opening of the

is a small area above the superior concha. It receives the

The sphenoethmoidal recess

Sphenoethmoidal Recess

meatus.

The space below each concha is called a

(Fig. 11.93).

inferior nasal conchae

superior, middle,

The lateral wall has three projections of bone called the

Lateral Wall

downward sloping body of the sphenoid (Fig. 11.93).

beneath the anterior cranial fossa, and posteriorly by the

middle by the cribriform plate of the ethmoid, located

bridge of the nose by the nasal and frontal bones, in the

The roof is narrow and is formed anteriorly beneath the

Roof

of the palatine bone (Fig. 11.92)

The palatine process of the maxilla and the horizontal plate

conchae have been partially removed to show openings of the paranasal sinuses and the nasolacrimal duct into the meati.

Lateral wall of the right nasal cavity; the superior, middle, and inferior

Lateral wall of the right nasal cavity. B.

Floor

and

Basic Anatomy

The paranasal sinuses are cavities found in the interior of the

by vessels that pass to the upper deep cervical nodes.

dibular nodes. The remainder of the nasal cavity is drained

The lymph vessels draining the vestibule end in the subman

Lymph Drainage of the Nasal Cavity

accompany the arteries.

bule. The submucous venous plexus is drained by veins that

labial branch of the facial artery in the region of the vesti

artery anastomoses with the septal branch of the superior

sphenopalatine artery (Fig. 11.95). The sphenopalatine

external carotid artery. The most important branch is the

the maxillary artery, one of the terminal branches of the

The arterial supply to the nasal cavity is from branches of

Blood Supply to the Nasal Cavity

(Fig. 11.94).

and the maxillary division (V2) of the trigeminal nerve

sensation are branches of the ophthalmic division (V1)

to the olfactory bulbs (Fig. 11.94). The nerves of ordinary

ascend through the cribriform plate of the ethmoid bone

The olfactory nerves from the olfactory mucous membrane

Nerve Supply of the Nasal Cavity

which are then swallowed and destroyed by gastric acid.

traps foreign particles and organisms in the inspired air,

tem. The presence of mucus on the surfaces of the conchae

to heat up the inspired air as it enters the respiratory sys

The presence of warm blood in the venous plexuses serves

Function of Warm Blood and Mucus of Mucous

present in the respiratory region.

large plexus of veins in the submucous connective tissue is

nasal cavity is lined with respiratory mucous membrane. A

sensitive to the reception of smell. The lower part of the

olfactory mucous membrane and contains nerve endings

hairs. The area above the superior concha is lined with

The vestibule is lined with modified skin and has coarse

Mucous Membrane of the Nasal Cavity

decreasing the size of the other.

thus increasing the size of one half of the nasal cavity and

the septal cartilage. The septum rarely lies in the midline,

the vomer (Fig. 11.92). The anterior part is formed by

part is formed by the vertical plate of the ethmoid and

The medial wall is formed by the nasal septum. The upper

Medial Wall

membrane (Fig. 11.93).

which is guarded by a fold of mucous

nasolacrimal duct,

rior concha and receives the opening of the lower end of the

The inferior meatus lies below the infe

Inferior Meatus

hiatus semilunaris.

meatus through the

opens into the middle

maxillary sinus

The

frontal sinus.

which is continuous with the

infundibulum,

nel called the

anterior end of the hiatus leads into a funnel-shaped chan

lies just below the bulla (Fig. 11.93). The

tus semilunaris,

which open on its upper border. A curved opening, the

middle ethmoidal air sinuses,

that is formed by the

bulla ethmoi

concha. It has a rounded swelling called the

The middle meatus lies below the middle

Middle Meatus

641

dalis

hia-

Membrane

The Paranasal Sinuses

maxilla, frontal, sphenoid, and ethmoid bones (Fig. 11.97).

the voice is markedly changed.

are blocked or they become filled with fluid, the quality of

the weight of the skull. When the apertures of the sinuses

sinuses is to act as resonators to the voice; they also reduce

ated during the blowing of the nose. The function of the

age of the mucus is also achieved by the siphon action cre

into the nose by ciliary action of the columnar cells. Drain

The mucus produced by the mucous membrane is moved

Drainage of Mucus and Function of Paranasal

adolescence.

ciably after the eighth year and become fully formed in

present in a rudimentary form at birth; they enlarge appre

small apertures. The maxillary and sphenoidal sinuses are

they communicate with the nasal cavity through relatively

They are lined with mucoperiosteum and filled with air;

Sinuses

-
-

olfactory

nerves

olfactory

nerves

medial posterior

superior nasal

nerves (V2)

nasopalatine

nerve (V2)

olfactory bulb

olfactory

bulb

olfactory tract

lateral posterior
superior nasal
nerves (V2)

lateral posterior
inferior nasal
nerves (V2)

lesser palatine
nerve (V2)

greater palatine nerve (V2)

pharyngeal
nerve (V2)

ethmoidal

nerve (V1)

internal nasal
nerve from
anterior
ethmoidal
nerve (V1)

external nasal

nerve (V1)

internal

nasal

nerve

(V1)

FIGURE 11.94

sensory innervation of mucous membrane.

Nasal septum showing

Lateral wall of nasal cavity showing sensory innervation of mucous membrane. B.

642

CHAPTER 11

The Head and Neck

anterior ethmoidal
artery (ophthalmic)

Kiesselbach’s
area

septal branch
from facial
artery

posterior ethmoidal
artery (ophthalmic)

sphenopalatine
artery
(maxillary)

septal branches of

sphenopalatine artery

(maxillary)

lesser palatine
artery (maxillary)

lesser palatine

artery (maxillary)

greater palatine

artery (maxillary)

greater palatine
artery (maxillary)

branches

from

facial

artery

posterior ethmoidal

artery (ophthalmic)

FIGURE 11.95

Nasal septum showing

Lateral wall of nasal cavity showing the arterial supply of the mucous membrane. B.

the arterial supply of the mucous membrane.

Examination of the Nasal Cavity

The most common cause is nose picking. The bleeding may be

like conchae make impaction and retention of balloons, peas,

placed downward and inward. Lateral fractures also occur in

Examination of the nasal cavity may be carried out by inserting

a speculum through the external nares or by means of a mirror

in the pharynx. In the latter case, the choanae and the posterior

border of the septum can be visualized (Fig. 11.91).

It should be remembered that the nasal septum is rarely situ-

ated in the midline. A severely deviated septum may interfere

with drainage of the nose and the paranasal sinuses.

Trauma to the Nose

Fractures involving the nasal bones are common. Blows directed

from the front may cause one or both nasal bones to be dis-

which one nasal bone is driven inward and the other outward;

the nasal septum is usually involved.

Infection of the Nasal Cavity

Infection of the nasal cavity can spread in a variety of direc-

tions. The paranasal sinuses are especially prone to infection.

Organisms may spread via the nasal part of the pharynx and the

auditory tube to the middle ear. It is possible for organisms to

ascend to the meninges of the anterior cranial fossa, along the

sheaths of the olfactory nerves through the cribriform plate, and

produce meningitis.

Foreign Bodies in the Nose

Foreign bodies in the nose are common in children. The pres-

ence of the nasal septum and the existence of the folded, shelf-

and small toys relatively easy.

Nose Bleeding

Epistaxis, or bleeding from the nose, is a frequent condition.

arterial or venous, and most episodes occur on the anteroinfe-

rior portion of the septum and involve the septal branches of the

sphenopalatine and facial vessels.

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

Development of the Nose

process on each side. At this stage, the floors of the olfactory

the medial nasal process and the anterior part of the maxillary

lary process. As these processes fuse, the olfactory pits become

The roof of the nose is formed from the lateral nasal processes,

from which the lateral walls also are formed, with the assistance

of the maxillary processes (Fig. 11.43). The anterior openings of

the nose begin as olfactory pits in the frontonasal process. Each

olfactory pit is bounded medially by the medial nasal process,

laterally by the lateral nasal process, and inferiorly by the maxil-

deeper and form well-defined blind sacs, the opening into each

of which is the nostril.

The floor of the nose at first is very short and consists of

pits rupture so that the nasal cavities communicate with the

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

(continued)

Basic Anatomy

643

developing mouth (Fig. 11.82). Meanwhile, the nasal septum is

tened structure and gains its recognizable form only after the

11.82). Later, the palatal processes of the maxilla grow medially

forming as a downgrowth from the medial nasal process (Fig.

and fuse with each other and with the nasal septum, thus com-

pleting the floor of the nose. Each nasal cavity therefore com-

municates anteriorly with the exterior through the nostril and

posteriorly through the choana with the nasopharynx.

In the early stages of development, the nose is a much-flat-

facial development is complete.

Median Nasal Furrow
In median nasal furrow, the nasal septum is split, separating the

two halves of the nose (Fig. 11.96A).

Lateral Proboscis
In lateral proboscis, a skin-covered process develops, usually

with a dimple at its lower end (Fig. 11.96B).

FIGURE 11.96

nose through the infundibulum (Fig. 11.93).

Each frontal sinus opens into the middle meatus of the

into the medial part of the roof of the orbit.

upward above the medial end of the eyebrow and backward

a bony septum. Each sinus is roughly triangular, extending

bone (Fig. 11.97). They are separated from each other by

The two frontal sinuses are contained within the frontal

Frontal Sinuses

the nose through the hiatus semilunaris (Fig. 11.97).

teeth. The maxillary sinus opens into the middle meatus of

the floor is related to the roots of the premolars and molar

(Fig. 11.97). The roof is formed by the floor of the orbit, and

within the body of the maxilla behind the skin of the cheek

The maxillary sinus is pyramidal in shape and located

wide furrow. (Courtesy of L. Thompson.)

the nose. Note that the external nares are separated by a

septum has completely split, separating the two halves of

Median nasal furrow in which the nasal

B. Lateral probos-

cis. (Courtesy of R. Chase.)

Maxillary Sinus

frontal sinus

anterior ethmoidal sinuses

ethmoidal sinuses

orbit

middle ethmoidal sinuses

posterior
ethmoidal
sinuses

sphenoid
sinuses

maxillary
sinuses

crista galli

superior
concha

inferior
concha

maxillary
sinus

nasal septum

hard palate

middle concha

hiatus
semilunaris

FIGURE 11.97

cavity showing the ethmoidal and the maxillary sinuses.

relation to the face.

The position of the paranasal sinuses in

B. Coronal section through the nasal

644

CHAPTER 11

summarized in Table 11.11.

The various sinuses and their openings into the nose are

the posterior sinuses open into the superior meatus.

the middle meatus, on or above the bulla ethmoidalis; and

open into the infundibulum; the middle sinuses open into

spread from the sinuses into the orbit. The anterior sinuses

the latter by a thin plate of bone so that infection can readily

the nose and the orbit (Fig. 11.97). They are separated from

and they are contained within the ethmoid bone, between

The ethmoidal sinuses are anterior, middle, and posterior

noethmoidal recess above the superior concha.

noid bone (Fig. 11.97). Each sinus opens into the sphe

The two sphenoidal sinuses lie within the body of the sphe

The Head and Neck

Sphenoidal Sinuses

-
-

Ethmoid Sinuses

Paranasal Sinuses and Their

Site of Drainage into the Nose

T A B L E 1 1 . 1 1

Sinusitis and the Examination of the Paranasal

by pressing the finger upward beneath the medial end of the

Sinuses

Infection of the paranasal sinuses is a common complica-

tion of nasal infections. Rarely, the cause of maxillary sinus-

itis is extension from an apical dental abscess. The frontal,

ethmoidal, and maxillary sinuses can be palpated clinically

for areas of tenderness. The frontal sinus can be examined

superior orbital margin. Here, the floor of the frontal sinus is

closest to the surface.

The ethmoidal sinuses can be palpated by pressing the

finger medially against the medial wall of the orbit. The maxil-

lary sinus can be examined for tenderness by pressing the fin-

ger against the anterior wall of the maxilla below the inferior

orbital margin; pressure over the infraorbital nerve may reveal

increased sensitivity.

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

(continued)

Directing the beam of a flashlight either through the roof of

Crossing of Air and Food Pathways in the

because its drainage orifice through the hiatus semilunaris is

the mouth or through the cheek in a darkened room will often

enable a physician to determine whether the maxillary sinus is

full of inflammatory fluid rather than air. This method of transil-

lumination is simple and effective. Radiologic examination of

the sinuses is also most helpful in making a diagnosis. One

should always compare the clinical findings of each sinus on

the two sides of the body.

The frontal sinus is innervated by the supraorbital nerve,

which also supplies the skin of the forehead and scalp as far

back as the vertex. It is, therefore, not surprising that patients

with frontal sinusitis have pain referred over this area. The

maxillary sinus is innervated by the infraorbital nerve and, in

this case, pain is referred to the upper jaw, including the teeth.

The frontal sinus drains into the hiatus semilunaris, via the

infundibulum, close to the orifice of the maxillary sinus on the

lateral wall of the nose. It is thus not unexpected to find that

a patient with frontal sinusitis nearly always has a maxillary

sinusitis. The maxillary sinus is particularly prone to infection

badly placed near the roof of the sinus. In other words, the

sinus has to fill up with fluid before it can effectively drain with

the person in the upright position. The relation of the apices of

the roots of the teeth in the maxilla to the floor of the maxillary

sinus was already emphasized.

Pharynx

muscles, and lined by mucous membrane.

are held together by ligaments and membranes, moved by

The framework of the larynx is formed of cartilages that

and at the sides by the thyroid gland.

larynx is covered in front by the infrahyoid strap muscles

pharynx, and below is continuous with the trachea. The

(Fig. 11.87). It opens above into the laryngeal part of the

at the level of the fourth, fifth, and sixth cervical vertebrae

and between the great blood vessels of the neck and lies

production. It is situated below the tongue and hyoid bone

at the inlet of the air passages and is responsible for voice

The larynx is an organ that provides a protective sphincter

use of wind instruments such as the trumpet.

maximum expiration of air through the mouth as in the

the respiratory system through the mouth. It also allows the

an arrangement permits the expectoration of mucus from

the mouth rather than the narrow cavities of the nose. Such

of the larynx, the soft palate is raised to direct air through

desirable to direct the maximum amount of air in and out

the nasopharynx in swallowing (see page XXX). When it is

ynx from the oropharynx, thus preventing food entering

The completely raised soft palate can shut off the nasophar

chewing food so that breathing may continue unaffected.

from the oropharynx, for example, during the process of

which serves as a flap valve. This flap shuts off the mouth

This is made possible by the presence of the soft palate,

It is in the pharynx that the air and food pathways cross.

The Larynx

Sinus

Site of Drainage

Maxillary sinus

Middle meatus through hiatus semi-

lunaris

Frontal sinuses

Middle meatus via infundibulum

Sphenoidal sinuses

Sphenoethmoidal recess

Ethmoidal sinuses
Anterior group

Infundibulum and into middle meatus

Middle group

Middle meatus on or above bulla

ethmoidalis

Posterior group

birth, enlarge appreciably after the eighth year, and are fully formed in adolescence.

*Note that maxillary and sphenoidal sinuses are present in rudimentary form at

Superior meatus

Basic Anatomy

lation with the inferior cornu of the thyroid cartilage.

on each side of the lateral surface is a facet for articu

cricoid cartilage lies below the thyroid cartilage, and

behind and a shallow arch in front (Fig. 11.98). The

lage and shaped like a signet ring, having a broad plate

This cartilage is formed of hyaline carti

Cricoid cartilage:

lamina is an oblique line for the attachment of muscles.

On the outer surface of each

inferior cornu.

into an

and downward

superior cornu

extends upward into a

angle (the so-called Adam’s apple). The posterior border

cartilage that meet in the midline in the prominent V

ynx (Fig. 11.98) and consists of two laminae of hyaline

This is the largest cartilage of the lar

Thyroid cartilage:

Cartilages of the Larynx

645

Posteriorly, the lamina has on its upper border on each

ytenoid muscles.

ally gives attachment to the posterior and lateral cricoar

that projects later

muscular process

vocal ligament. A

that projects forward and gives attachment to the

cess

vocal pro

with the lamina of the cricoid cartilage, and a

below that articulates

small corniculate cartilage, a

above that articulates with the

apex

cartilage has an

upper border of the lamina of the cricoid cartilage. Each

back of the larynx (Fig. 11.98). They articulate with the

which are small and pyramid shaped and located at the

There are two arytenoid cartilages,

Arytenoid cartilages:

All these joints are synovial.

side a facet for articulation with the arytenoid cartilage.

base

-
-

arch of cricoid cartilage

epiglottis

hyoid bone

lateral thyrohyoid

ligament

superior cornu

lamina of thyroid

cartilage

inferior cornu

arch of cricoid

cartilage

cricotracheal ligament

trachea

cricothyroid ligament

oblique line

thyrohyoid membrane

thyrohyoid ligament

lateral thyrohyoid ligament

epiglottis

hyoid bone

thyrohyoid membrane

thyrohyoid ligament

cricothyroid ligament

cricothyroid muscle

lamina of cricoid cartilage

epiglottis

greater cornu of hyoid

bone

thyrohyoid membrane

corniculate

cartilage

arytenoid

cartilage

lamina of thyroid

cartilage

muscular process

trachealis muscle

hyoepiglottic ligament

epiglottis

greater cornu of

hyoid bone

superior cornu of

thyroid cartilage

aryepiglottic fold

cuneiform cartilage

corniculate cartilage

arytenoid cartilage

muscular process

vocal process

lamina of cricoid

cartilage

body of hyoid bone

thyrohyoid membrane

thyroid cartilage

right vestibular fold

right vocal ligament

cricothyroid ligament

arch of cricoid

cartilage

FIGURE 11.98

The larynx and its ligaments from the front

lamina of thyroid cartilage has been removed to display the interior of the larynx.

The left

(A), from the lateral aspect (B), and from behind (C). D.

646

CHAPTER 11

The Head and Neck

greater cornu of hyoid bone

epiglottis

tubercle

of epiglottis

aryepiglottic
muscle

aryepiglottic

muscle

oblique
arytenoid
muscle

transverse
arytenoid
muscle

posterior
cricoarytenoid
muscle

trachea

lamina of cricoid cartilage

thyroid cartilage

arytenoid cartilage

corniculate cartilage

cuneiform cartilage

thyrohyoid membrane

epiglottis

aryepiglottic fold

piriform fossa

quadrangular membrane

saccule

thyroid cartilage

vestibular fold

vestibular ligament

sinus

vocal fold
vocalis

vocal ligament

cricothyroid ligament

cricoid cartilage

rima glottidis

first ring of trachea

vocal fold

vestibular fold

rima glottidis

cuneiform cartilage

corniculate cartilage

thyroid cartilage

rima glottidis

vocal ligament

arytenoid cartilage

thyroid cartilage

rima glottidis

vocal process

arytenoid cartilage

muscular process

vocal ligament

vocalis

lateral cricoarytenoid muscle

posterior cricoarytenoid muscle

transverse arytenoid muscle

oblique arytenoid muscle

FIGURE 11.99

Corniculate cartilages:

Muscles that move vocal ligaments.

Rima glottidis wide open as in deep breathing.

open as in quiet breathing.

Rima glottidis partially

Coronal section through the larynx.

Muscles of the larynx seen from behind. B.

Two small conical-shaped cartilages

(Fig. 11.90). Laterally, the mucous

vallecula

called the

the depression on each side of the fold is

glottic fold;

median glossoepi

terior surface of the tongue as the

of mucous membrane passes forward onto the pos

The upper edge of the epiglottis is free. The covering

lages by the aryepiglottic folds of mucous membrane.

of the epiglottis are attached to the arytenoid carti

attached to the back of the thyroid cartilage. The sides

behind the root of the tongue (Fig. 11.98). Its stalk is

This leaf-shaped lamina of elastic cartilage lies

Epiglottis:

strengthen them (Fig. 11.99).

lages are found in the aryepiglottic folds and serve to

These two small rod-shaped carti

Cuneiform cartilages:

give attachment to the aryepiglottic folds.

articulate with the arytenoid cartilages (Fig. 11.99). They

membrane passes onto the wall of the pharynx as the
lateral glossoepiglottic fold.

epiglottis and the arytenoid cartilages (Fig. 11.99).

This extends between the

Quadrangular membrane:

to the first ring of the trachea (Fig. 11.98).

This connects the cricoid cartilage

Cricotracheal ligament:

a branch of the superior laryngeal nerve (Fig. 11.80).

superior laryngeal vessels and the internal laryngeal nerve,

The membrane is pierced on each side by the

ligament.

median thyrohyoid

midline, it is thickened to form the

the thyroid cartilage to the hyoid bone (Fig. 11.98). In the

This connects the upper margin of

Thyrohyoid membrane:

Membranes and Ligaments of the Larynx

Basic Anatomy

lowing. Note that many of these muscles are attached to

These muscles move the larynx up and down during swal

extrinsic and intrinsic.

The muscles of the larynx may be divided into two groups:

mucous secretion lubricates the vocal cords.

membrane that ascends from the sinus (Fig. 11.99). The

The saccule of the larynx is a diverticulum of mucous

Saccule of the Larynx

lined with mucous membrane (Fig. 11.99).

larynx situated between the vestibular and vocal folds. It is

The sinus of the larynx is a small recess on each side of the

above and the lower border of the cricoid cartilage below

which is situated between the vocal folds

lower region,

The

lar folds above and the vocal folds below

which is situated between the vestibu

middle region,

The

vestibular folds

which is situated between the inlet and the

vestibule,

The

the cavity of the trachea. It is divided into three regions:

border of the cricoid cartilage, where it is continuous with

The cavity of the larynx extends from the inlet to the lower

Cavity of the Larynx

the larynx within the cricoid cartilage is the narrowest part.

adult and less in the female. In children, the lower part of

and measures about 2.5 cm from front to back in the male

noid cartilages. The glottis is the narrowest part of the larynx

the vocal folds and behind by the medial surface of the aryte

(Fig. 11.99). The glottis is bounded in front by

glottis

rima glotti

The gap between the vocal folds is called the

(Fig. 11.99).

with a laryngoscope

respiration and its white color is easily seen when viewed

The vocal fold moves with

in color.

white

avascular and

by mucous membrane covering the vocal ligament and is

ynx and is concerned with voice production. It is formed

fold on each side of the lar

mobile

The vocal fold is a

Vocal Fold (Vocal Cord)

in color.

the vestibular ligament and is vascular and

(Fig. 11.98). It is formed by mucous membrane covering

fold on each side of the larynx

fixed

The vestibular fold is a

Vestibular Fold

Laryngeal Folds

hyoid membrane.

tic fold and laterally by the thyroid cartilage and the thyro

inlet (Fig. 11.99). It is bounded medially by the aryepiglot

The piriform fossa is a recess on either side of the fold and

The Piriform Fossa

a small elevation on the upper border.

within and strengthens the aryepiglottic fold and produces

with the corniculate cartilages. The cuneiform cartilage lies

membrane, and posteriorly by the arytenoid cartilages

the epiglottis, laterally by the aryepiglottic fold of mucous

is wider in front than behind and is bounded in front by

the laryngeal part of the pharynx (Fig. 11.88). The opening

The inlet of the larynx looks backward and upward into

arytenoid cartilage.

posterior end is attached to the vocal process of the

ligament is attached to the thyroid cartilage, and the

(Fig. 11.99). The anterior end of each vocal

cords)

vocal folds (vocal

ligaments form the interior of the

on each side. The vocal

vocal ligament

important

composed almost entirely of elastic tissue, forms the

surface of the thyroid cartilage. Its upper free margin,

attached to the thyroid cartilage, ascends on the medial

The superior margin of the ligament, instead of being

the upper border of the cricoid cartilage (Fig. 11.99).

The lower margin is attached to

Cricothyroid ligament:

(Fig. 11.99).

vestibular folds

and the vestibular ligaments form the interior of

ment,

vestibular liga

Its thickened inferior margin forms the

647

the

Inlet of the Larynx

-
-

pink

dis

Sinus of the Larynx

Muscles of the Larynx

Extrinsic Muscles

the hyoid bone, which is attached to the thyroid cartilage by

cartilages apart so that the posterior part of the glottis is open.

the capsules of the cricoarytenoid joints keeps the arytenoid

and abducts the vocal process (Fig. 11.99). The elastic tissue in

terior cricoarytenoid, which rotates the arytenoid cartilage

The rima glottidis is opened by the contraction of the pos

of the cricoid cartilage.

and down on the sloping shoulder of the superior border

ments of the arytenoid cartilages, which rotate and slide up

The movements of the vocal folds depend on the move

Movements of the Vocal Folds (Cords)

Table 11.12.

action of the intrinsic muscles of the larynx are given in

The details of the origins, insertions, nerve supply, and

arytenoid muscle

The transverse

Approximates the arytenoid cartilages:

enoid muscle

The posterior cricoaryt

Abducting the vocal cords:

muscle

The lateral cricoarytenoid

Adducting the vocal cords:

muscle

The thyroarytenoid (vocalis)

Relaxing the vocal cords:

The cricothyroid muscle

Tensing the vocal cords:

Five muscles move the vocal folds (cords) (Fig. 11.99):

The thyroepiglottic muscle

Widening the inlet:

The oblique arytenoid muscle

Narrowing the inlet:

Two muscles modify the laryngeal inlet (Fig. 11.99):

omohyoid muscles

The sternothyroid, the sternohyoid, and the

Depression:

geus, and the palatopharyngeus muscles

geniohyoid, the stylopharyngeus, the salpingopharyn

The digastric, the stylohyoid, the mylohyoid, the

Elevation:

hyoid bone are accompanied by movements of the larynx.

the thyrohyoid membrane. It follows that movements of the

Intrinsic Muscles

■

648

CHAPTER 11

The Head and Neck

Intrinsic Muscles of the Larynx

T A B L E 1 1 . 1 2

Muscle

Origin

Insertion

Nerve Supply

Action

Muscles Controlling the Laryngeal Inlet
Oblique arytenoid

Muscular process of

arytenoid cartilage

Voice Production in the Larynx

producing a grunting sound.

some of the air by momentarily opening the rima glottidis,

tract. After a prolonged effort, the person often releases

by the presence of compressed air within the respiratory

and the upward movement of the diaphragm is prevented

The muscles of the anterior abdominal wall now contract,

glottidis. After deep inspiration, the rima glottidis is closed.

held temporarily in the respiratory tract by closing the rima

with micturition, defecation, and parturition, air is often

against a closed glottis. In abdominal straining associated

In the Valsalva maneuver, forced expiration takes place

where the material is either swallowed or expectorated.

respiratory tract and carry the material up into the pharynx,

air will often dislodge foreign particles or mucus from the

suddenly abducted. The sudden release of the compressed

result, the intrathoracic pressure rises, and the vocal folds are

the muscles of expiration are made to contract strongly. As a

sphincter. After inspiration, the vocal folds are adducted, and

In coughing or sneezing, the rima glottidis serves as a

the laryngeal inlet, the piriform fossae.

the epiglottis or moving down the grooves on either side of

food, or fluids, then enters the esophagus by passing over

and serves as a cap over the laryngeal inlet. The bolus of

muscles. The epiglottis is pulled backward by the tongue

by the action of the oblique arytenoid and aryepiglottic

the back of the tongue. The inlet of the larynx is narrowed

tongue and the hard palate, the larynx is pulled up beneath

ing. As the bolus of food is passed backward between the

The sphincter at the inlet is used only during swallow

rima glottidis.

sphincters in the larynx: one at the inlet and another at the

There are two

Sphincteric Function of the Larynx

the arytenoid cartilages (Fig. 11.99).

diamond shape because of the maximal lateral rotation of

abducted and the triangular shape of the glottis becomes a

On deep inspiration, the vocal folds are maximally

a small gap between them (Fig. 11.99).

11.99). On expiration, the vocal folds are adducted, leaving

glottidis is triangular in shape with the apex in front (Fig.

inspiration, the vocal folds are abducted and the rima

On quiet

Movements of the Vocal Folds with Respiration

muscle (Fig. 11.99).

by contraction of the vocalis, a part of the thyroarytenoid

thyroid muscle (Fig. 11.100). The vocal folds are slackened

The vocal folds are stretched by contraction of the crico

by contraction of the transverse arytenoid muscles.

is narrowed when the arytenoid cartilages are drawn together

the vocal process (Fig. 11.99). The posterior part of the glottis

coarytenoid, which rotates the arytenoid cartilage and adducts

The rima glottidis is closed by contraction of the lateral cri

Transverse

Tenses vocal cords

Muscles Controlling the Movements of the Vocal Folds (Cords)

Apex of opposite

arytenoid cartilage

Recurrent

laryngeal nerve

Narrows the inlet by bring-

ing the aryepiglottic folds

together

Thyroepiglottic

Medial surface of thyroid

cartilage

Lateral margin of

epiglottis and arye-

piglottic fold

Recurrent

laryngeal nerve

Widens the inlet by pulling the

aryepiglottic folds apart

Cricothyroid

Side of cricoid cartilage

Lower border and

inferior cornu of

thyroid cartilage

External

laryngeal nerve

Thyroarytenoid

(vocalis)

Inner surface of thyroid

cartilage

Arytenoid cartilage

Recurrent

laryngeal nerve

Relaxes vocal cords

Lateral

cricoarytenoid

Upper border of cricoid

cartilage

Muscular process of

arytenoid cartilage

Recurrent

laryngeal nerve

Adducts the vocal cords by

rotating arytenoid cartilage

Posterior

cricoarytenoid

Back of cricoid cartilage

Muscular process of

arytenoid cartilage

Recurrent

laryngeal nerve

Abducts the vocal cords by

rotating arytenoid cartilage

arytenoid

Back and medial surface of

arytenoid cartilage

Back and medial

surface of opposite

arytenoid cartilage

Recurrent

laryngeal nerve

Closes posterior part of rima

glottidis by approximating

arytenoid cartilages

tongue, teeth, and lips. Vowel sounds are usually purely

into recognizable consonants and vowels by the use of the

Normal speech depends on the modification of the sound

plate, tongue, floor of the mouth, cheeks, lips, and jaws.

quality of the voice is controlled by the muscles of the soft

namely, the pharynx, mouth, and paranasal sinuses. The

of the voice depends on the resonators above the larynx,

quality

the length and tension of the vocal ligaments. The

of the sound is determined by changes in

pitch,

quency,

fre

their vibration and in the production of sound. The

of expired air between the adducted vocal folds results in

The intermittent release

Basic Anatomy

649

relaxed

right vocal

ligament (cord)

external view of

right lamina of

thyroid cartilage

cricothyroid

muscle

cricoid

cartilage

internal view of

right lamina of

thyroid cartilage

vocal process

right arytenoid

cartilage

lamina of

cricoid cartilage

stretched

right vocal

ligament (cord)

relaxed

right vocal

ligament (cord)

cri

internal v

right lami

thyroid ca

vocal

righ

cart

lamin

cricoid

stretched

right vocal

ligament (cord)

FIGURE 11.100

hments and

Diagrams showing the attac

nodes.

The lymph vessels drain into the deep cervical group of

Lymph Drainage of the Larynx

of the inferior thyroid artery

The inferior laryngeal branch

Lower half of the larynx:

of the superior thyroid artery

The superior laryngeal branch

Upper half of the larynx:

of the vagus.

external laryngeal branch of the superior laryngeal branch

laryngeal nerve. The cricothyroid muscle is supplied by the

the cricothyroid muscle are supplied by the recurrent

All the intrinsic muscles of the larynx except

Motor Nerves

geal nerve (Fig. 11.101)

The recurrent laryn

Below the level of the vocal cords:

the superior laryngeal branch of the vagus

The internal laryngeal branch of

Above the vocal cords:

Sensory Nerves

Nerve Supply of the Larynx

is covered with stratified squamous epithelium.

repeated trauma during phonation, the mucous membrane

cords, however, where the mucous membrane is subject to

is covered with ciliated columnar epithelium. On the vocal

The mucous membrane of the larynx lines the cavity and

Mucous Membrane of the Larynx

glottidis.

air that passes through the posterior part of the rima

the vibrations are given to a constant stream of expired

tilting backward by contraction of the cricothyroid muscles.

stretched as a result of the cricoid and arytenoid cartilages

Interior view of the larynx showing the right vocal ligament

larynx showing the relaxed right vocal ligament.

Interior view of the

the larynx and the cricothyroid muscle.

Right lateral view of

actions of the cricothyroid muscle. A.

■

Blood Supply of the Larynx

■

internal laryngeal

nerve

superior

laryngeal

branch of

vagus nerve

exterior

laryngeal

nerve

recurrent

laryngeal

nerve

recurrent

laryngeal

nerve

recurrent
laryngeal
nerve
(mucous
membrane
removed)

cricothyroid
muscle

FIGURE 11.101

adducted, but the arytenoid cartilages are separated;

adducted vocal folds. In whispering, the vocal folds are

a more prolonged release of the expired air between the

a note requires

Singing

between the adducted vocal folds.

involves the intermittent release of expired air

Speech

through the mouth rather than the nose.

oral with the soft palate raised so that the air is channeled

The larynx is viewed from above and posteriorly.

nal branches of the internal and recurrent laryngeal nerves.

The distribution of the termi

branch of the vagus nerve.

and external laryngeal branches of the superior laryngeal

Lateral view of larynx showing the internal

650

CHAPTER 11

The Head and Neck

Lesions of the Laryngeal Nerves

the blade tip has left the esophagus, it is in the laryngeal part

and is, therefore, distal to the level of the vocal cords. Once

Remember that the tip of the blade is at first in the esophagus

all times and is permitted to rise up out of the esophagus.

drawn. The tip of the blade is kept under direct vision at

is anatomically). The blade should by now have moved toward

fully inserted into the esophagus (so that you know where it

and down into the esophagus. The tip of the blade must be

molar teeth. The blade can then be passed over the tongue

the blade is correctly placed alongside the right mandibular

The laryngoscope is inserted into the patient’s mouth, and

lished and the patient has assumed the “sniffing” position.

The patient’s head and neck are correctly positioned so that

If the patient is asked to breathe deeply, the vocal folds become

clearly seen. The two elevations produced by the corniculate

a pillow and the head is fully extended at the atlanto-occipital

tidis to swell and encroach on the airway. In severe cases, a cri

The mucous membrane of the larynx is loosely attached to the

drawing together of the vocal folds (Fig. 11.102). Acute breath

results in bilateral paralysis of the abductor muscles and the

Bilateral partial section of the recurrent laryngeal nerve

than of the adductor muscles. The affected vocal fold assumes

vocal fold compensates to some extent and moves toward the

of the voice because the vocal fold cannot be tensed. The crico

rent laryngeal nerves may be damaged by malignant involve

deposits in the mediastinal lymph nodes. The right and left recur

geal nerves, with the exception of the cricothyroid muscle, which

The muscles of the larynx are innervated by the recurrent laryn-

is supplied by the external laryngeal nerve. Both these nerves

are vulnerable during operations on the thyroid gland because

of the close relationship between them and the arteries of the

gland. The left recurrent laryngeal nerve may be involved in a

bronchial or esophageal carcinoma or in secondary metastatic

ment of the deep cervical lymph nodes.

Section of the external laryngeal nerve produces weakness

thyroid muscle is paralyzed (Fig. 11.102).

Unilateral complete section of the recurrent laryngeal nerve

results in the vocal fold on the affected side assuming the posi-

tion midway between abduction and adduction. It lies just lateral

to the midline. Speech is not greatly affected because the other

affected vocal fold (Fig. 11.102).

Bilateral complete section of the recurrent laryngeal nerve

results in both vocal folds assuming the position midway between

abduction and adduction. Breathing is impaired because the

rima glottidis is partially closed, and speech is lost (Fig. 11.102).

Unilateral partial section of the recurrent laryngeal nerve

results in a greater degree of paralysis of the abductor muscles

the adducted midline position (Fig. 11.102). This phenomenon

has not been explained satisfactorily. It must be assumed that

the abductor muscles receive a greater number of nerves than

the adductor muscles, and thus partial damage of the recurrent

laryngeal nerve results in damage to relatively more nerve fibers

to the abductor muscles. Another possibility is that the nerve

fibers to the abductor muscles are traveling in a more exposed

position in the recurrent laryngeal nerve and are therefore more

prone to be damaged.

lessness (dyspnea) and stridor follow, and cricothyroidotomy or

tracheostomy is necessary.

Edema of the Laryngeal Mucous Membrane

underlying structures by submucous connective tissue. In the

region of the vocal folds, however, the mucous membrane is

firmly attached to the vocal ligaments. This fact is of clinical

importance in cases of edema of the larynx. The accumulation of

tissue fluid causes the mucous membrane above the rima glot-

cothyroidotomy or tracheostomy may be necessary.

Laryngeal Mirror and Laryngoscope

The interior of the larynx can be inspected indirectly through a

laryngeal mirror passed through the open mouth into the oral

pharynx (Fig. 11.103). A more satisfactory method is the direct

method using the laryngoscope. The neck is brought forward on

joints. The illuminated instrument can then be introduced into the

larynx over the back of the tongue (Fig. 11.103). The valleculae,

the piriform fossae, the epiglottis, and the aryepiglottic folds are

and cuneiform cartilages can be recognized. Within the larynx,

the vestibular folds and the vocal folds can be seen. The former

are fixed, widely separated, and reddish in color; the latter move

with respiration and are white in color. With quiet breathing,

the rima glottidis is triangular, with the apex in front. With deep

inspiration, the rima glottidis assumes a diamond shape because

of the lateral rotation of the arytenoid cartilages.

widely abducted, and the inside of the trachea can be seen.

Important Anatomic Axes for Endotracheal Intubation

The upper airway has three axes that have to be brought into

alignment if the glottis is to be viewed adequately through a

laryngoscope—the axis of the mouth, the axis of the pharynx,

and the axis of the trachea (Fig. 11.104).

The following procedures are necessary: First, the head is

extended at the atlanto-occipital joints. This brings the axis of

the mouth into the correct position. Then, the neck is flexed at

cervical vertebrae C4 to C7 by elevating the back of the head off

the table, often with the help of a pillow. This brings the axes of

the pharynx and the trachea in line with the axis of the mouth.

Anatomy of the Visualization of the Vocal Cords with the
Laryngoscope

■

The pear-shaped epiglottis is attached by its stalk at its lower

end to the interior of the thyroid cartilage (Fig. 11.98).

■

The vocal cords (ligaments) are attached at their anterior

ends to the thyroid cartilage just below the attachment of the

epiglottis (Fig. 11.98).

■

Because of the above two facts, it follows that manipulation

of the epiglottis and possibly the thyroid cartilage will greatly

assist the operator in visualizing the cords and the glottis.

the three axes of the airway (noted above) have been estab-

the midline and followed the anatomic curvature on the poste-

rior surface of the tongue.

The laryngoscopic blade is then gently and slowly with-

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

(continued)

Basic Anatomy

651

of the pharynx (Figs. 11.88 and 11.91), and a view of the glottis

changes are largely mediated through the branches of the

lar changes such as bradycardia and hypertension. These

during the process of intubation may produce cardiovascu

Stimulation of the mucous membrane of the upper airway

Again use your knowledge of anatomy. With the right

epiglottis to expose the glottis. If the glottis is still not in view,

Now use your anatomic

the glottis is not visualized, then the operator is viewing the

should immediately be apparent. This is the critical stage. If

posterior surface of the epiglottis.
knowledge.

With the tip of the blade of the laryngoscope applied to the

posterior surface of the epiglottis, gently lift up and elevate the

not panic!

free hand, grasp the thyroid cartilage (to which the cords and the

epiglottis are attached) between finger and thumb and apply firm

backward, upward, rightward pressure (BURP). This maneuver

realigns the box of the larynx relative to the laryngoscopic blade,

and the visual axis of the operator and the glottis should imme-

diately be seen.

Reflex Activity Secondary to Endotracheal Intubation

vagus nerves.

rima

glottidis

epiglottis

right vocal
fold (cord)

aryepiglottic fold

corniculate cartilage

inspiration

phonation

inspiration

Bilateral
external laryngeal
nerve palsy

Unilateral
complete section
of right recurrent
laryngeal nerve

Unilateral partial section
of right recurrent
laryngeal nerve

Bilateral
complete section
of recurrent laryngeal
nerves

Bilateral partial section
of recurrent laryngeal
nerves

deep cervical nodes

Into the pretracheal and paratracheal lymph nodes and the

Lymph Drainage of the Trachea

arteries.

arteries and the lower third is supplied by the bronchial

The upper two thirds is supplied by the inferior thyroid

Blood Supply of the Trachea

laryngeal nerves.

The sensory nerve supply is from the vagi and the recurrent

Nerve Supply of the Trachea

the thorax are described on page 63.

The relations of the trachea in the superior mediastinum of

sheath and contents (Fig. 11.49)

Lobes of the thyroid gland and the carotid

Laterally:

and the esophagus

Right and left recurrent laryngeal nerves

Posteriorly:

lapped by the sternothyroid and sternohyoid muscles

sent), and the left brachiocephalic vein in children, over

thyroid vein, jugular arch, thyroidea ima artery (if pre

(in front of the second, third, and fourth rings), inferior

Skin, fascia, isthmus of the thyroid gland

Anteriorly:

Relations of the Trachea in the Neck

many goblet cells and tubular mucous glands.

pseudostratified ciliated columnar epithelium and contains

The mucous membrane of the trachea is lined with

muscle.

trachealis

tilage are connected by smooth muscle, the

embedded in its wall. The posterior free ends of the car

U-shaped cartilaginous bar (rings) of hyaline cartilage

The fibroelastic tube is kept patent by the presence of

thoracic vertebrae).

the sternal angle (opposite the disc between the 4th and 5th

into right and left principal (main) bronchi at the level of

by dividing

carina

In the thorax, the trachea ends at the

6th cervical vertebra. It descends in the midline of the neck.

at the lower border of the cricoid cartilage at the level of the

tube (Fig. 11.105). It begins as a continuation of the larynx

The trachea is a mobile cartilaginous and membranous

Description

The Trachea

■

-
-

■

FIGURE 11.102

The position of the vocal folds (cords) after

damage to the external and recurrent laryngeal nerves.