Region 6: Prevertebral Region and Pharynx
Deep Cervical Fascia
--Investing fascia of the deep cervical fascia (superficial or anterior layer)
*splits to inest the trapezius, sternomastoid, omohyoid, and infrahyoids
--Prevertebral fascia of the deep cervical fascia (deep or posterior layer)
*extends into the axilla as the axillary sheath
*surrounds 7 muscles in the prevertebral region: ant. scalene, middle
scalene, post. scalene, longus capitus, longus colli, rectus capitus ant., rectus
capitus lateralis
*the compartment enclosed within the prevertebral layer of fascia is know as
the prevertebral region
--Carotid sheath
*condensation of fascia which encloses the carotid arteries, internal jugular
vein, and vagus nerve
--Visceral fascia
*surrounds the viscera of the neck
Spaces in the Head and Neck
--Retropharyngeal Space
*located behind pharynx
*important b/c of downward spread of infection
Pharynx
--muscular tube lined with mucous membrane that extends from the base of the
skull down to the level of C6
--lies posterior to the nose, mouth, and larynx
--divided into 3 parts
a. Nasopharynx: nasal part
*communicates with the nasal cavities through the choanae
*auditory/Eustachian tube opens into it
*torus tubarius: elevation made by auditory tube
*salpingopharyngeal fold: with underlying muscle of same name
*pharyngeal tonsils/adenoids: mass of lymphoid tissue embedded in
the mucous membrane of the upper posterior wall (enlarged
pharyngeal tonsils are known as adenoids)
*torus levatorus: fold of mucous membrane produced by the levator
veli palatini muslce
b. Oropharynx: oral part
*posterior to the mouth and tongue
*communicates with the mouth through the oropharyngeal isthmus
(fauces)
*contains the palatine tonsils (located lateral to the tongue, below the
soft palate, and b/w the palatoglossal and palatopharyngeal folds,
lymphatic ring formed by pharyngeal tonsil aove, palatine tonsils
laterally, and lingual tonsils below (Waldeyer’s ring)
*mucous membrane of the epiglottis is reflected onto the base of the
tongue (one median and 2 lateral glossoepiglottic folds, depression
b/w them are valleculae)
c. Laryngopharynx: laryngeal part
*posterior to the larynx
*anterior wall includes back of the larynx and piriform recesses
*branches of the internal laryngeal nerve and superior laryngeal
vessels are located under the mucous membrane of piriform recess
--Buccopharyngeal Fascia: contains pharyngeal plexus of nerves
--Pharyngeal Muscles
a. Constrictors: all of them insert into a median raphe
*Superior pharyngeal constrictor muscle: origin from medial
pterygoid plate, hamulus, pterygomandibular raphe
*Middle pharyngeal constrictor muscle: origin from hyoid bone
*Inferior pharyngeal constrictor muscle: origin from thyroid and
cricoid cartilages
b. Stylopharyngeus Muscle
*origin from styloid process
*enters pharynx b/w superior and middle constrictor muscles
*inn. by glossopharyngeal nerve
c. palatopharyngeus muscle
d. salpingopharyngeus muscle: origin from auditory tube
--Structures Related to Pharyngeal Constrictor Muscles
a. glossopharyngeal nerve and stylopharyngeus muscle: pass b/w superior
and middle constrictor muscles
b. internal laryngeal nerve and superior laryngeal artery: pass b/w middle
and inferior constrictor muscles
c. recurrent laryngeal nerve and inferior laryngeal artery: b/w inferior
constrictor and esophagus
--Nerves Related to the Pharynx
a. glossopharyngeal nerve (CN IX)
*exits jugular forament
*supplies: carotid sinus (baroreceptors), stylopharyngeus muscle
(motor), posterior 1/3 of tongue (with taste and general sense)
b. Vagus Nerve (CN X)
*exits jugular forament and parallels carotid artery
*superior laryngeal nerve
--internal branch: pierces the thyrohyoid membrane, sensory
and parasympathetic to supraglotti mucosa
--external branch: motor to the cricothyroid and inferior
pharyngeal constrictor muscles
*pharyngeal nerves: motor to pharynx and soft and hard palate
* inferior laryngeal nerve/recurrent laryngeal nerve
--major motor nerve to intrinsic laryngeal muscles with
sensory and parasympathetic nerves to the subglottic mucosa
c. Spinal Accessory nerve (CN XI)
*exits jugular forament
*spinal part: originates from upper cervical spine (motor to SCM and
trapezius mm.)
d. Hypoglossal Nerve (CN XII)
*exits the hypoglossal canal
*enters the tongue b/w mylohyoid and hyoglossus muscles
*motor nerve to the tongue
e. Sympathetic trunk
*POSTganglionic fibers in internal carotid nerve or plexus follow the
internal carotid artery into head
f. pharyngeal plexus
*formed by fibers from glossopharyngeal nerve (CN IX), vagus nerve
(CN X), and sympathetic trunk
--Blood Vessels Related to the Pharynx
a. Carotid arteries
*internal carotid arteries
--NO branches in neck
*External carotid arteries: Anterior Branches
--superior thyroid artery
--lingual artery
--facial artery
*External carotid arteries: Medial Branch
--ascending pharyngeal artery
*External carotid arteries: Posterior Branches
--occipital artery
--posterior auricular artery
*External carotid arteries: Terminal Branches
--maxillary artery
--superficial temporal artery
b. Internal jugular vein
*retromandibular v. + posterior auricular form the external jugular v.