Anatomy Lecture 8 The Pharynx and Esophagus Pharynx is divided into 3 regions



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Anatomy Lecture 8 – The Pharynx and Esophagus


  • Pharynx is divided into 3 regions:

    • Nasopharynx – Nasal cavity above the Soft Palate

    • Oropharynx – From Soft Palate to Epiglottis

    • Laryngopharynx (Hypo) – From Epiglottis to Cricoid Cartilage

  • Muscles of the Pharynx

    • Superior Constrictor Muscle (attached by Pterygo-Mandibular Raphae) to the Buccinator Muscle

    • Middle Constrictor Muscle – Attaches to Hyoid Bone

    • Inferior Constrictor – Attaches to Thyroid Cartilage

  • Structures found in the Retropharyngeal Space (behind the Pharynx)

    • Thyroid Gland

    • Sympathetic Chain (Superior Cervical Ganglion)

    • Spinal Accessory Nerve

    • Glossopharyngeal Nerve

    • Hypoglossal Nerve

    • Carotid Sheath

      • Common Carotid

      • Internal Jugular

      • Vagus Nerve

    • Stylopharyngeus Muscle – CN IX – Elevates Larynx for swallowing

    • Superior, Middle, Inferior Constrictor Muscles

  • Nasopharynx:

    • Torus Tubarius: cartilaginous ring around the opening of the Eustachian Tube (auditory tube)

    • Eustachian Tube: tube that links the Nasopharynx to the Middle Ear – equilibrates pressure (ROOT OF INFECTION, esp. in children)

    • Salpingopharyngeus Muscle: Acts to raise the Pharynx during swallowing – CN X

    • Levator Veli Palatini Muscle: Elevates the Soft Palate – CN IX

    • Tensor Veli Palatini Muscle: Tenses the Soft Palate – CN V3

    • Velo-Lingual Seal – When you’re breathing, the Uvula sits on the tongue

    • Velo-Pharyngeal Seal – When you swallow, the Tensor and Levator open the Eustachian Tube

    • Adenoids: one of the filters that remove particles from the air before it moves into the trachea (from the nose)

    • Velum: The Soft Palate

  • Oropharynx:

    • Muscles: Elevate the tongue to push food up and back

      • Palatoglossus Muscles: CN X

      • Palatopharyngeous Muscles: CN X

    • Tonsillar Fossa with Palatine Tonsils

      • Severe bleeding can occur via External Palatine Vein (From Facial Vein)

    • Lingual Tonsils: Posterior 1/3 of the tongue. Enlargement can cause gag reflex and dysphagia

    • Waldeyer’s Ring: The ring of lymphoid tissues (tonsils) that protext the oro-nasal region from infection

      • Adenoids

      • Tubal Tonsils

      • Palatine Tonsils

      • Lingual Tonsils

  • Laryngopharynx

    • Piriform Recesses: extend inferior the Lateral Glossopiglottic Folds on either side of the larynx. Food and liquid can be stuck in these recesses upon deglutition

      • Cancers can develop here

    • Zenker’s Diverticulum:

      • Killian Laimer Triangle: triangle made from the Inferior Constrictor Muscle meets the Cricopharyngeal Muscle (weak spot) – herniations occur here

      • Leads to outpouching of the Posterior Pharyngeal Wall just above the Cricopharyngeal Muscle

      • Causes dysphagia

      • Vagus runs through here – so hoarseness can occur

  • Reflexes:

    • Carotid Reflex from the Carotid Body (O2-CO2) and Carotid Sinus (Baroreception) -- Glossopharyngeal

      • Afferent: CN IX

      • Efferent CN X

    • GAG Reflex:

      • Afferent: CN IX

      • Efferent: CN X

  • Enteric Nervous System:

    • Peristalsis

  • Barrett’s Esophagus:

    • Persistent GERD (Acid Reflux) can lead to changes the esophageal lining

      • Lower Esophageal Sphincter opens too frequently

    • The Z-Line was shifted up.

    • Causes Dysphasia

  • Achalasia

    • The Lower Esophageal Sphincter (LES) opens less frequently (primary) or is completely paralyzed (secondary).

    • This leads to reduced or absent peristalsis, which then causes esophageal obstruction

    • Loss of Enteric Innervation, which normally relaxes the LES

    • Can use Botox Injections

  • Esophageal Varices

    • Veins in the esophagus that can swell and occlude the lumen

  • Mallory-Weiss Syndrome:

    • Tear at the Esophago-Gastric Junction caused by vomiting

    • Can happen during pregnancy

    • Patients vomit blood

  • Boerhaave’s Syndrome

    • Caused by sudden rupture of esophagus allows entry of air into the peritoneal or pericardial cavities

    • Symptoms: Dyspnea (shortness of breath), Tachypnea (Rapid Breathing), Cyanosis, Shock



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