Download Anatomy Lecture 8 – The Pharynx and Esophagus

Anatomy Lecture 8 – The Pharynx and Esophagus
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Pharynx is divided into 3 regions:
o Nasopharynx – Nasal cavity above the Soft Palate
o Oropharynx – From Soft Palate to Epiglottis
o Laryngopharynx (Hypo) – From Epiglottis to Cricoid Cartilage
Muscles of the Pharynx
o Superior Constrictor Muscle (attached by Pterygo-Mandibular
Raphae) to the Buccinator Muscle
o Middle Constrictor Muscle – Attaches to Hyoid Bone
o Inferior Constrictor – Attaches to Thyroid Cartilage
Structures found in the Retropharyngeal Space (behind the Pharynx)
o Thyroid Gland
o Sympathetic Chain (Superior Cervical Ganglion)
o Spinal Accessory Nerve
o Glossopharyngeal Nerve
o Hypoglossal Nerve
o Carotid Sheath
 Common Carotid
 Internal Jugular
 Vagus Nerve
o Stylopharyngeus Muscle – CN IX – Elevates Larynx for swallowing
o Superior, Middle, Inferior Constrictor Muscles
Nasopharynx:
o Torus Tubarius: cartilaginous ring around the opening of the
Eustachian Tube (auditory tube)
o Eustachian Tube: tube that links the Nasopharynx to the Middle Ear –
equilibrates pressure (ROOT OF INFECTION, esp. in children)
o Salpingopharyngeus Muscle: Acts to raise the Pharynx during
swallowing – CN X
o Levator Veli Palatini Muscle: Elevates the Soft Palate – CN IX
o Tensor Veli Palatini Muscle: Tenses the Soft Palate – CN V3
o Velo-Lingual Seal – When you’re breathing, the Uvula sits on the
tongue
o Velo-Pharyngeal Seal – When you swallow, the Tensor and Levator
open the Eustachian Tube
o Adenoids: one of the filters that remove particles from the air before it
moves into the trachea (from the nose)
o Velum: The Soft Palate
Oropharynx:
o Muscles: Elevate the tongue to push food up and back
 Palatoglossus Muscles: CN X
 Palatopharyngeous Muscles: CN X
o Tonsillar Fossa with Palatine Tonsils
Severe bleeding can occur via External Palatine Vein (From
Facial Vein)
o Lingual Tonsils: Posterior 1/3 of the tongue. Enlargement can cause
gag reflex and dysphagia
o 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
o 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
o 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:
o Carotid Reflex from the Carotid Body (O2-CO2) and Carotid Sinus
(Baroreception) -- Glossopharyngeal
 Afferent: CN IX
 Efferent CN X
o GAG Reflex:
 Afferent: CN IX
 Efferent: CN X
 Enteric Nervous System:
o Peristalsis
 Barrett’s Esophagus:
o Persistent GERD (Acid Reflux) can lead to changes the esophageal
lining
 Lower Esophageal Sphincter opens too frequently
o The Z-Line was shifted up.
o Causes Dysphasia
 Achalasia
o The Lower Esophageal Sphincter (LES) opens less frequently
(primary) or is completely paralyzed (secondary).
o This leads to reduced or absent peristalsis, which then causes
esophageal obstruction
o Loss of Enteric Innervation, which normally relaxes the LES
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o Can use Botox Injections
 Esophageal Varices
o Veins in the esophagus that can swell and occlude the lumen
 Mallory-Weiss Syndrome:
o Tear at the Esophago-Gastric Junction caused by vomiting
o Can happen during pregnancy
o Patients vomit blood
 Boerhaave’s Syndrome
o Caused by sudden rupture of esophagus allows entry of air into the
peritoneal or pericardial cavities
o Symptoms: Dyspnea (shortness of breath), Tachypnea (Rapid
Breathing), Cyanosis, Shock