Posterior Triangle and Suboccipital Region



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Pharynx and Larynx


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The pharynx functions in respiration and ingestion and is divided into three sections: nasopharynx, oropharynx, and laryngopharynx. The nasopharynx is posterior to the nasal cavity and superior of the oral cavity. The oropharynx is from the back of the oral cavity down to the larynx. The laryngopharynx is the lowest area dorsal to larynx.

Nasopharynx

Border

Structures

Inferior

Soft Palate

Superior/Posterior

Sphenoid and Occipital bones, Sup. constrictor muscle

Lateral

Auditory tube, Torus tubarius


Structures found in the nasopharynx: choanae (openings to nasal cavity), auditory tube, torus tubarius, pharyngeal tonsil, salpingopharyngeal fold, pharyngeal tonsil, salpingopharyngeal fold.


  • Auditory Tube:

  • levator veli palatini: origin: floor of auditory tube and petrous ridge of temporal bone; insertion: soft palate

  • tensor veli palatini: origin: cartilage of auditory tube and medial pterygoid plate

Fun Fact: you pop your ears by contracting the tensor veli palatini and salpingopharyngeus and levator palatini to open up the auditory tubes (also open when you swallow)

Oropharynx



Border

Structures

Inferior

Epiglottis & larynx

Superior

Soft palate

Posterior

wall of throat

Anterior

terminal sulcus

Structures found in the oropharynx: back of the tongue, lingual tonsil, palatoglossal fold, palatopharyngeal fold, salpingopharyngeal fold, palatine tonsil

  • Vascular supply from: lesser palatine a., ascending pharyngeal a., facial a., lingual a.

  • Waldeyer's ring:lymphoid tissue

    • pharyngeal tonsil

    • palatine tonsil

    • tubal tonsil

    • lingual tonsil

Laryngeopharynx

Structures found in the laryngeopharynx: Epiglottis, epiglottic valleculae (little valleys at base of tongue), pyriform recess (swallowed foreign bodies may be lodged here), circumferential muscles: superior, middle, and inferior pharyngeal constrictors (superficial; overlap like shingles), longitudinal muscles: palatopharyngeus, salpingopharyngeus (luminal side), stylopharyngeus (this muscle along with CN IX passes between superior and middle constrictors).

Note: Understand that while swallowing voluntary muscles do the work initially but then gradually involuntary muscles take over the process (larynx is elevated; pharynx is widened).

Muscle

Origin

Insert

Innervated By

Function

Circumferential mm (Pharynx)













Sup. Pharyngeal Constrictor

Medial Pterygoid Plate, pterygomandibular raphe

Median Pharyngeal Raphe

CN X




Mid. Pharyngeal Constrictor

Greater and Lesser Horns of Hyoid

Median Pharyngeal Raphe

CN X




Inf. Pharyngeal Constrictor

Oblique line of thyroid cartilage, cricoid cartilage

Median Pharyngeal Raphe

CN X




Longitudinal mm (Pharynx)













Salpingopharyngeus

Medial Auditory Tube

Palatopharyngeus m

CN X

Elevates pharynx, opens auditory tube

Palatopharyngeus

Aponeurosis of Soft Palate

Dorsal border of Thyroid Cartilage

CN X

Constricting pharynx, depresses soft palate, elevates pharynx and larynx

Palatoglossus

Aponeurosis of Soft Palate

Posterior Lateral Tongue

CN X

Elevates sides of tongue, depresses soft palate

Stylopharyngeus

Styloid Process

Dorsal Border of Thyroid Cartilage

CN IX

Elevates pharyngeal wall and thyroid cartilage

Intrinsic mm (Larynx)













Cricothyroids

Anterior Cricoid Cartilage

Inf. Thyroid Cartilage

External laryngeal

Rotates thyroid cartilage ant & inf, tenses vocal folds

Lateral Cricoarytenoids

Cranial margin of Cricoid Cartilage

Muscular Process of Arytenoids Cartilage

Recurrent laryngeal

Adducts vocal folds

Transverse Arytenoids

Posterior concave surface of arytenoids cartilage

Post concave surface of arytenoids cartilage of opposite side

Recurrent laryngeal

Adducts vocal folds

Oblique Arytenoids

Muscular process of arytenoids cartilage

Apex of arytenoid cartilage of opposite side

Recurrent laryngeal

Adducts vocal folds

Posterior Cricoarytenoids

Posterior cricoid cartilage

Muscular process of arytenoids cartilage

Recurrent laryngeal

Abduction of vocal folds

Thyroarytenoids

Inside lamina of thyroid cartilage

Lateral margin of arytenoids cartilage

Recurrent laryngeal

Relaxes vocal folds, antagonist of cricothyroid

Vocalis

Inner surface of thyroid cartilage

Vocal process of arytenoids cartilage

Recurrent laryngeal

Relaxes vocal ligaments



Larynx


Surface features

epiglottis, vestibule, aryepiglottic folds, false vocal cords (a.k.a. ventricular fold), ventricle, true vocal folds, vocal ligaments, rima glottidis

Palpable landmarks



  • hyoid bone

  • thyroid cartilage

  • cricothyroid ligament

  • cricoid cartilage

Artery / Nerve Pairings

  • Superior laryngeal artery runs with internal

    • laryngeal nerve

  • Inferior laryngeal artery runs with recurrent

    • laryngeal nerve

Nerves

Nerve

Innvervates

Type

Internal laryngeal n

True vocal cords

Sensory

External laryngeal n

Cricothyroid m

Motor

Recurrent laryngeal n

All other portions of larynx

Sensory and Motor

CN X and symp trunk

Smooth muscle

Autonomics



Unpaired cartilages

  • epiglottis

  • thyroid cartilage

  • crycoid cartilage

Paired cartilages

  • arytenoids cartilages

  • corniculate cartilages

  • cuniform cartilages

Ligaments

  • thyrohyoid membrane

  • cricothyroid lig.

  • vocal lig.

  • vestibular lig.

  • conus elasticus (cricovocal lig.)

Extrinsic muscles

  • infrahyoid and suprahyoid

Infrahyoid muscles

  • 3 adductors (speech):

    • lateral cricoarytenoids

    • oblique arytenoids

    • transverse arytenoids.

  • 1 abductor (breathing)

    • posterior cricoarytenoids

  • 1 tensor

    • cricothyroids

  • 2 relaxers

    • thyroarytenoids

    • vocalis

  • 1 vocal ligament

    • ummm, self descriptive

Review Questions

1) Damage to the external laryngeal nerve during thyroid surgery could result in the inability to



  • a. relax the vocal cords

  • b. rotate the arytenoid cartilages

  • c. tense the vocal cords

  • d. widen the rima glottidis

  • e. abduct the vocal cords

2) If the patient is unable to abduct the vocal cords during quiet breathing, which of the following muscles is paralyzed?

  • a. Vocalis m.

  • b. Cricothyroid m.

  • c. Oblique arytenoid m.

  • d. Posterior cricoarytenoid m.

  • e. Thyroarytenoid m.

3) Which of the following pairs of muscles is most instrumental in preventing food from entering the larynx and trachea during swallowing?

  • a. Sternohyoid and sternothyroid mm.

  • b. Oblique arytenoid and aryepiglottic mm.

  • c. Inferior pharyngeal constrictor and thyrohyoid mm.

  • d. Levator veli palatini and tensor veli palatini mm.

  • e. Musculus uvulae and geniohyoid mm.

Answers
1) C


2) D
3) B (Remember that the vocal cords dominate the epiglottis in preventing food and other material from going down the trachea)




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