Pharynx & Larynx

Olaleye O.O. 2B10

•  Pharynx

–  Subdivisions and borders

–  Pharyngeal muscles

–  Pharyngeal gaps

–  Blood supply and innervation

•  Larynx

–  Laryngeal cartilages

Paired vs. unpaired

Basic structure

Membranes and ligaments

–  Vocal cords and folds

–  Muscles and innervation

–  Blood supply

•  Is a wide muscular tube

•  12 cm in length

•  Located posterior to the nasal and oral cavities

•  Extends inferiorly, posterior to the larynx

•  Extends from the cranial base to the inferior border of the cricoid

cartilage (anteriorly) and inferior border of C6 (posteriorly) [Extends

from the base of the skull to the level of the C6 vertebra]where it is

continuous with the oesophagus

•  Widest opposite the hyoid bone and narrowest at the junction where

it joins the oesophagus

Pharyngeal wall

The wall of the Pharynx consists of five layers:

1.  Mucous membrane

2.  Submucosa

3.  Pharyngobasilar fascia

4.  Pharyngeal muscles (3 constrictors)

1.  Stylopharyngeus

2.  Salpingopharyngeus

3.  palatopharyngeus

5.  Buccopharyngeal fascia

•  Nasopharynx

•  Oropharynx

•  Laryngopharynx

•  Respiratory function

•  Roof and Posterior wall:

Continuous surface that lies inferior to the body of the sphenoid bone

and the basilar part of the occipital bone

•  Pharyngeal tonsils:

Found in the mucous membrane of the roof and the posterior wall of

the nasopharynx

•  Digestive function

•  Aids in the process of deglutition

•  Borders

Superiorly: Soft Palate

Inferiorly: Base of the Tongue

Laterally: Palatoglossal and Palatopharyngeal arches

•  Palatine tonsils

–  Collections of lymphoid tissue on either side of the Oropharynx

between the arches

•  Tonsillar bed

–  Superior constrictor of the pharynx and the pharyngobasilar fascia

form the tonsillar bed

•  Extends from the superior border of the epiglottis and the pharyngoepiglottic

folds to the inferior border of the cricoid cartilage

•  Borders

Posteriorly:

related to the bodies of the C4- C6 vertebrae

Posterior and lateral walls:

Middle and Inferior constrictor muscles

•  Palatopharyngeus and Stylopharyngeus muscles form the walls

•  Piriform recess, small depression of the laryngopharyngeal cavity on either

side of the laryngeal inlet

•  Separated from the laryngeal inlet by the aryepiglottic fold

2 layers of voluntary muscle:

•  External circular layer

•  Internal circular layer

External circular layer

• Constrictor muscles

• Primarily responsible for constricting the pharynx during swallowing

• Mainly innervated by the pharyngeal branch of vagus and the

pharyngeal plexus

• Middle and Inferior constrictor muscles are also innervated by the

external and recurrent laryngeal nerves

•  Internal Longitudinal layer

•  Elevate/shorten and widen the pharynx during swallowing and speaking

•  Palatopharyngeus

•  Stylopharyngeus

•  Salpingopharyngeus

•  Palatopharyngeus and salpingopharyngeus are innervated by the

pharyngeal branch of CNX and the pharyngeal plexus

•  Stylopharyngeus is innervated by CN IX

•  1. Cranium to Superior Constrictor muscle

Levator Veli Palatini

Pharyngotympanic tube

Ascending palatine artery

•  2. Superior Constrictor to Middle Constrictor

Stylopharyngeus

Glossopharyngeal nerve

Stylohyoid ligament

•  3. Middle Constrictor to Inferior Constrictor

Internal laryngeal nerve

Superior laryngeal artery and vein, which passes to the larynx

•  4. Inferior to the Inferior Constrictor Muscle

Recurrent Laryngeal nerve

Inferior Laryngeal artery

Supply to the upper parts of the pharynx

•  Ascending pharyngeal artery

•  Ascending palatine artery

•  Tonsillar branches of the facial artery

•  Branches of the maxillary and lingual arteries

Supply to the lower parts of the pharynx

•  Pharyngeal branches of the inferior thyroid artery

LARYNX

•  Is the upper , expanded part of the windpipe

which is modified for phonation

•  Supported by a number of cartilages

•  Complex organ of voice production

•  Composed of 9 cartilages connected by membranes and ligaments

•  Contains the vocal folds

•  Located anteriorly in the neck

•  Vertebral levels C3-C6

•  Connects the inferior part of the Oropharynx to the trachea

•  Lies anterior to the Laryngopharnx

•  Secondary function is to guard the air passages

•  3 unpaired cartilages

Thyroid

Cricoid

Epiglottic

•  3 paired cartilages

Arytenoid

Cuneiform

Corniculate

•  Main divisions of the Laryngeal Cavity

Laryngeal Vestibule

Middle part of the laryngeal cavity

Laryngeal Ventricle

Infraglottic cavity

•  Vocal folds and ligaments

•  Quadrangular membrane

Muscle Origin Insertion Innervation Action

Cricothyroid Antero-lateral part of cricoid cartilage

Inferior margin and inferior horn of thyroid cartilage

External laryngeal nerve

Stretches and tenses vocal ligament

Thyro-arytenoid Lower ½ of posterior aspect of angle of thyroid laminae and cricothyroid ligament

Anterolateral arytenoid surface

Inferior laryngeal nerve (terminal part of recurrent laryngeal nerve from vagus)

Relaxes valocal ligament

Posterior Crico-arytenoid

Posterior surface of lamina of cricoid cartilage

Vocal process of arytenoid cartilage

Abducts vocal folds

Lateral crico-arytenoid

Arch of arytenoid cartilage

Adducts vocal folds

Transverse & Oblique arytenoids

One arytenoid cartilage

Contra-lateral arytenoid cartilage

Adducts arytenoid cartilages

Vocalis Lateral surface of vocal process of arytenoid cartilages

Ipsilateral vocal ligament Relaxes posterior vocal ligament while maintaining tension of anterior part

•  Superior Laryngeal artery

Supplies the internal surface of the larynx

•  Cricothyroid artery

Supplies the cricothyroid muscle

•  Inferior Laryngeal artery

Supplies the mucous membrane and the muscles of the inferior part of the

larynx