Region 6: Prevertebral Region and Pharynx Deep Cervical Fascia



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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.





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