Oropharynx Anatomy

🍽️ What is the Oropharynx?

The oropharynx is the second part of the pharynx, lying in continuation with the nasopharynx.

It lies opposite the oral cavity, communicating with it via the oropharyngeal isthmus.

What are the boundaries of Oropharyngeal Isthmus?

📏 Extent of the Oropharynx

• Upper limit: Horizontal plane at the level of the hard palate.

• Lower limit: Horizontal plane through the hyoid bone (at the level of the vallecula, upper border of the epiglottis, and pharyngoepiglottic folds).

🌍 Boundaries of the Oropharynx

1. Roof

• Formed at the level of the hard palate.

2. Floor

• Formed by the floor of the vallecula.
• Also corresponds to the upper border of the epiglottis and the pharyngoepiglottic folds.

3. Posterior Wall

• Lies adjacent to the retropharyngeal space.
• Lies opposite C2 and upper part of C3 vertebrae.

4. Anterior Wall

• Deficient superiorly, allowing communication with the oral cavity via the oropharyngeal isthmus.

• Below, lined by the following structures:

  • Posterior third of the dorsum of the tongue
  • Lingual tonsils
  • Vallecula
    • Cup-shaped depressions between the base of the tongue and the anterior surface of the epiglottis.

What are the boundaries of Vallecula?

Which type of cyst is commonly formed in Vallecula?

5. Lateral Walls

Main structures:

• Palatine Tonsils
  • Part of Waldeyer’s ring.
  • Located in the tonsillar fossa.

Name all the structures forming the Waldeyer's Ring.

• Anterior pillar (Palatoglossal arch)

  • Formed by the Palatoglossus muscle.

• Posterior pillar (Palatopharyngeal arch)

  • Formed by the Palatopharyngeus muscle.

🩸 Lymphatic Drainage of Oropharynx

• Jugulodigastric lymph nodes (Primary node for tonsils and oropharynx)
• Retropharyngeal and Parapharyngeal lymph nodes → Jugulodigastric and posterior cervical groups
• Base of tongue may have bilateral drainage.

🧠 Nerve Supply of Oropharynx

• Vallecula: Supplied by the Internal Laryngeal nerve (branch of Superior Laryngeal nerve, which is a branch of Vagus nerve).

• Rest of oropharynx mucosa:

  • Predominantly by the Glossopharyngeal nerve (CN IX).
  • Partially by the Lesser Palatine nerve.

⚙️ Functions of the Oropharynx

• Air and Food Conduction
• Deglutition
• Speech
• Taste Appreciation

Which areas are taste buds found in?

• Local Immunity