Dissection 10 - Pharynx and Larynx

Dissection Guide

Pharynx

• Fibromuscular tube that is closed posteriorly and laterally

  • 3 openings: nasal cavity, oral cavity, larynx

• Superior, middle, and inferior pharyngeal constrictors are located within the pretracheal fascia

• Stylopharyngeus located between ICA and gap between superior and middle constrictors

  • Angles obliquely and inferiorly from styloid process

  • CN IX wraps around m.

• ID superior cervical ganglion (superior end of each sympathetic trunk)

Diverticulum

• Can happen at the mucosa located at the juncture between pharyngeal constrictors and esophagus

  • M. have different orientations

Inside pharynx

• Nasopharynx: Sphenoid → uvula

  • Opening into nasal cavity = Choanae

• Oropharynx: Uvula → Superior tip of epiglottis

• Laryngopharynx: Epiglottis → Inferior margin of cricoid cartilage

  • Laryngeal outlet = opening into larynx

  • Areyepiglottic fold = next to laryngeal outlet

• Note that sharp objects gets stuck in the piriform recess

• Posterior cricoarytenoids and transverse and oblique arytenoid m. exposed

  • Posterior surface of cricoid lamina and arytenoid cartilage

  • Functions

    • Posterior cricoarytenoid: abduct vocal folds

    • Transverse and oblique m.: adduct vocal folds

Bisecting the head

• ID frontal, maxillary, and sphenoid sinuses

• Supraglottic = above vocal fold

• Infraglottic = below vocal fold

  • Innervated by recurrent laryngeal n.

Bolded Terms

Aryepiglottic folds

• Located next to laryngeal outlet

• Extends from epiglottis to paired arytenoid cartilage

Arytenoid cartilage

• “Cat ear” cartilage posterior to epiglottis

• Superior to cricoid cartilage

Atlanto-occipital joint

• Joint between occipital condyle and superior articular facet

Carotid body

• Chemoreceptor

• Located around CCA bifurcation

Carotid sinus

• Baroreceptor

• Located at CCA bifurcation

Cervical sympathetic trunks

• Path for sympathetics to enter head and neck

Common carotid a.

Cricoid cartilage

• Inferior to arytenoid cartilage

Cricothyroid m.

• Muscle that goes from cricoid cartilage to thyroid cartilage

• Innervated by external branch of superior laryngeal n. of CN X

• Contraction → Lengthen vocal cords (high pitch sounds)

Dens

Epiglottic valleculae

• On either side of midline in space between epiglottis and posterior tongue

• Place for food and liquid accumulation during swallowing and where food may be lodged

Epiglottis

• Marks transition between oropharynx and laryngopharynx

External branch of superior laryngeal n.

Foramen magnum

Frontal, maxillary, and sphenoid sinuses

Genioglossus

• Fan-like muscle of tongue

• Involved in protrusion and depression

Geniohyoid

• Inferior to genioglossus

• From genu to hyoid

Glossopharyngeal n.

• Innervates stylopharyngus

Glottis

• R and L true vocal folds and the space between them

Hard palate

Inferior constrictor

Infraglottic region

• Below vocal fold

Internal branch of suoerior laryngeal n.

Laryngeal outlet

• Opening into laryngopharynx

Laryngopharynx

• Epiglottis → inferior margin of cricoid cartilage

Larynx

• Most inferior opening into pharynx

Medial pterygoid plate

• Thin, elongated bony projection that descends from the sphenoid bone as part of the pterygoid process

• Important site for muscle attachment

Nasal choanae

• Opening into nasal cavity from nasopharynx

Nasopharynx

• Most superficial pharynx

• Sphenoid → Uvula

Oblique artyenoid m.

• Adducts vocal folds

Oropharynx

• Uvula → Superior end of epiglottis

Piriform recess

• Common place for sharp objects to get stuck

• Lateral to laryngeal outlet

Posterior arch of the atlas and the vertebral a.

Posterior cricoartytenoids

• Abduct volcal folds

Pterygoid hamulus

• A hook-like process around which the tendon of the tensor veli palatini muscle glide

• End of medial pterygoid plate

Recurrent laryngeal n.

• Innervates intrinsic laryngeal m. except for cricothyroid

Retropharyngeal space

• Space between buccopharyngeal fascia and prevertebral fascia

Semispinalis capitis

• Muscle fibers orient vertically

Soft palate

Stylopharyngeus

• Pierces into superior and middle pharyngeal constrictors

• Innervated by CN IX

Superior and middle pharyngeal constrictors

Superior cervical ganglion

• Most superior ganglion of sympathetic trunk

Transverse arytenoid m.

• Adducts volcal folds

Uvula

• Primarily innervated by CN X

Ventricle

• Space between vestibular and vocal folds

Vestibular folds

• Located superior to true folds

Vocal folds

• Located below vestibular folds