STEP PREP: Pharynx

Pharynx is commonly known as the

throat

Pharyngeal cavity includes the

nasopharynx, oropharynx, and laryngopharynx which are found behind their respective cavities.

Valleculae

A natural pocket in the pharynx

Is located where the tongue root and back of the epiglottis meet.

Serves as a reservoir where food or liquid briefly collects.

Pyriform sinuses

A natural pocket in the pharynx

Is located as a pocket on the outer edge of the arytenoids and pharynx walls.

Serves as a reservoir where food or liquid briefly collects.

At the epiglottis the bolus

typically divides into two pieces and moves around the piglottis and aryepiglottic folds toward the pyriform sinuses which then divert around the airway into the pyriform sinuses.

Pharyngeal constrictors have

"C-shaped" walls: posterior, right lateral, left lateral with an open anterior.

horizontally aligned fibers

Pharyngeal constrictors: contraction

= smaller diameter of c-shaped tube

3 sections (superior, inferior, and middle) sequentially contract to squeeze bolus downward.

Pharyngeal constrictors: Anterior attachments

Superior constrictor connects to the buccinator bilaterally via th pterygomandibular raphae.

Middle courses anteriorly and attach to the greater horns bilaterally.

Inferior courses anteriorly and attach to the oblique line of the thyroid cartilage bilaterally.

Longitudinal pharyngeal muscles

long narrow muscles that run vertically from structures above the pharynx through the pharynx.

Includes the salpingopharyngeous, palatopharyngeous, and stylopharyngeus.

Are the pharyngeal shorteners.

Interdigitated and attached to the pharyngeal constrictors.

When the longitudinal pharyngeal muscles contract

they elevate and thus shorten the pharynx as well as aid in elevating the constrictors.

Contraction of both the longitudinal pharyngeal muscles and constrictors result in

pharyngeal shortening and constriction.

the longitudinal pharyngeal muscles and constrictors attach to the

hyoid bone and larynx

Another function of the pharynx is to aid in

hyo-laryngeal elevation via pharyngeal shortening (airway protection during swallowing)

Epiglottis inverts to

protect the airway from food.

Pharyngeal mucosa

Pink layer of mucous membrane tissue that is soft and moist.

It lines body cavities and surrounds several organs.

Motor Innervation

All muscles of the pharynx, except stylopharyngeus, are innervated by the Pharyngeal Plexus: Pharyngeal branch of Vagus (CNX) Glossopharyngeal (CNIX)

stylopharyngeus is innervated by the glossopharyngeal (CNIX)

Sensory Innervation

Nasopharynx

Glossopharyngeal - CN IX

Oropharynx and Laryngopharynx

Pharyngeal Plexus CN IX and CNX