PHARYNX and LARYNX

Mikel H. Snow, Ph.D.Dental Anatomy

mikelhes@usc.eduJuly 23, 2018

Maxillary Artery, Left

External

carotid

Superficial

temporal

Deep auricular

Inferior alveolar

Middle meningeal

Accessory

meningeal

Masseteric

Deep

temporal

Deep

temporalLateral

pterygoid

Buccal

Medial

pterygoid

Infraorbital

Sphenopalatine

Pharyngeal

Artery of

pterygoid canal

Posterior superior

alveolar

Descending palatineAnterior tympanic

MylohyoidMental

Incisive

Nasal Cavity

Middle meningeal

artery

Ascends between roots of

auriculotemporal nerve

Posterior superior

alveolar artery pierces

back of maxilla

Inferior alveolar artery

goes with inferior

alveolar nerve to enter

mandibular foramen

Pterygomaxillary Fissure

Maxilla

Lateral

pterygoid

plate

The maxillary artery leaves the infratemporal fossa by passing thru

the pterygomaxillary fissure to enter the pterygopalatine fossa.

Its 3 terminal branches are: infraorbital, descending palatine and sphenopalatine.

Pharynx

Food & Air Passage

Objectives

Locate the pharynx relative to other areas of the head and neck.

Identify the muscles of pharynx and their innervation.

By the end of lecture, the student should be able to…

List the structures within each sub-region of the pharynx.

Locate the gag reflex and indicate the sensory nerve for this reflex.

Describe movements of soft palate & sealing of oropharynx from nose.

Summarize innervation of pharyngeal and laryngeal muscles.

Summarize deglutition and cranial nerves involved.

Pharynx

The pharynx is a fibromuscular tube with 3 regions that open anteriorly. The

upper part is an air passageway, the middle is a food/liquid & air passageway,

and the lower is a food/liquid passageway.

Nasal

cavity

Oral

cavity

Nasopharynx

Oropharynx

Laryngopharynx

Trachea

Food and drink

Air

Esophagus

Nasal cavity

Oral cavity

Larynx

Skeletal Muscles of Pharynx

Superior constrictor

Middle constrictor

Inferior constrictor

Stylopharyngeus

• Constrictors innervated by vagus

• Stylopharyngeus innervated by glossopharyngeal

Two additional internal

muscles we’ll get to later…

Glossopharyngeal nerve wraps

around stylopharyngeus muscle

and innervates it.Somatomotor branch of

vagus to constrictors

Key relationship: Glossopharyngeal nerve wraps around the

stylopharyngeus muscle.

Pharyngeal Plexus:

• VS to pharyngeal mucosa

• SM to pharyngeal constrictors

Pharynx Interior

Slit open

constrictors to

examine interior

Nasopharynx:

1. Pharyngeal tonsils

2

2. Auditory tube ostia 3. Salpingopharyngeal fold

Oropharynx:

3

4. Palatine tonsils

Laryngopharynx:

5. Piriform recess

55

44

1

1. Pharyngeal tonsils

1Nasal

cavity

Oral

cavity

2. Torus tubarius

2

3. Auditory tube opening

3

4. Salpingopharyngeal fold

4

1

23

5. Salpingopharyngeus muscle

5

6. Levator veli palatini muscle

6

7. Tensor veli palatini muscle

7

Lateral Wall of Pharynx

8. Palatine tonsil

9. Palatoglossal fold/muscle

10. Palatopharyngeus fold/muscle

89

9

1010

Summary Rule for Innervation of

Pharynx and Soft Palate Muscles

All muscles of the pharynx and palate are innervated

by the vagus nerve, except:

• Stylopharyngeus which is IX

• Tensor veli palatini which is V3

Deglutition

Stage 1

Tongue (XII) pushes

bolus against hard

palate.

Stage 2

Tongue (XII) pushes

bolus to oropharynx;

soft palate elevated

by levator (X) and

tensor (V3) veli

palatini.

Stage 3

Bolus pushes

epiglottis down to

cover laryngeal

inlet.

Stage 4

Pharyngeal

constrictors (X)

propel bolus into

esophagus.

Bolus

Sensory Innervation to Pharynx

Glossopharyngeal

Vagus

“Gag Reflex”

Larynx

Vocalization

Objectives

Name and locate the laryngeal cartilages.

Differentiate true vocal cords from false cords.

By the end of lecture, the student should be able to…

Define parts of the larynx: supraglottic, infraglottic, ventricle & glottis.

Summarize the sensory & ANS innervation to laryngeal mucosa.

Discuss action & innervation of muscles tensing & abducting cords.

Distinguish the gag reflex from the cough reflex.

LarynxExternal View

Hyoid

Thyroid cartilage

Cricoid cartilage

Arytenoid cartilages

Epiglottis

Trachea

Larynx functions in

phonation & respiration

LarynxInternal View

Cricoid

Thyroid

Epiglottis

Arytenoid

Vocal ligament

Vestibular ligament

LarynxInternal View with Mucosa

Cricoid

Epiglottis

Arytenoid

Vestibular fold

Vocal foldOpening into ventricle

Ventricle is a small cleflike pocket

between and lateral to vestibular

and vocal folds. It houses

mucous glands that moisten the

vocal cords.

Coronal section

LarynxLaryngoscopy

Glottis:

Vocal cords plus

space between

LarynxSensory Innervation

Supraglottic region

Infraglottic region

Internal br. superior laryngeal

Recurrent laryngeal

Taste to epiglottis

Internal br. superior laryngeal

Cough reflex

Internal branch superior

laryngeal nerve

Taste

Parasympathetic pre-ganglionic

Viscerosensory pain

Movements of the Vocal Cords

Laryngeal Muscles

8 pairs of muscles move vocal cords

Tenses cords

Cricothyroid

Abduction

Adduction

Adduction

Tensors

Synovial joint

Posterior

cricoarytenoid

muscle

One Muscle Abducts

Vocal Cords

LarynxMotor Innervation

Cricothyroid

External branch of

superior laryngeal nerve

All others

Recurrent laryngeal nerves

Any Questions?