Laryngopharynx Anatomy

🔍 What is the Laryngopharynx?

The laryngopharynx is the lowermost part of the pharynx, also known as the hypopharynx.

It forms the junction between the oropharynx and the esophagus.

📍 Location

• Lies behind and partly on the sides of the larynx.
• Lies opposite C3, C4, C5, and C6 vertebrae.
• Communicates with the larynx through the laryngeal inlet.

What are the boundaries of the Laryngeal Inlet?

📏 Extent of the Laryngopharynx

• Upper limit: Plane passing through the body of hyoid bone and superior margin of epiglottis

• Lower limit: Lower border of the cricoid cartilage (at the level of C6 vertebra) where it continues as the esophagus

🧩 Parts of the Laryngopharynx

The laryngopharynx is divided into three regions — the 3 Ps:

• Pyriform sinus
• Posterior pharyngeal wall
• Postcricoid area

1- Posterior Pharyngeal Wall

• Extends from the superior margin of hyoid bone to the inferior border of cricoid cartilage.
• Horizontal extent: From the apex of one pyriform recess to the other.
• Formed by the superior, middle, and inferior constrictor muscles up to the level of the vocal cords.

What is Killian’s Dehiscence and what is it's clinical importance?

2- Pyriform Sinus

• Located on either side of the laryngeal inlet.
• Extends from the lateral glossoepiglottic fold to the upper end of the esophagus.
• Wider superiorly and narrower inferiorly.

What are the boundaries of Pyriform Sinus?

3- Postcricoid Area

• Extends from the arytenoid cartilages and aryepiglottic folds to the inferior border of cricoid cartilage
• Forms the anterior wall of the hypopharynx

Which carcinomas are associated with Postcricoid area?

🧫 Lymphatic Drainage of Laryngopharynx

• Pyriform sinus: Drains through the thyrohyoid membrane into the upper jugular chain

• Posterior pharyngeal wall: Drains into lateral pharyngeal or parapharyngeal nodes, then into deep cervical nodes

• Postcricoid area: Drains into parapharyngeal nodes, supraclavicular nodes, and paratracheal nodes

🧠 Nerve Supply of Laryngopharynx

• Motor and sensory supply by the Pharyngeal Plexus, formed by the IX (Glossopharyngeal) and X (Vagus) cranial nerves

🩸 Blood Supply of Laryngopharynx

• From the Superior Thyroid Arteries along with collaterals from the Lingual and Ascending Pharyngeal arteries

⚙️ Functions of the Laryngopharynx

• Common pathway for air and food
• Provides part of the vocal tract, aiding in voice resonance
• Crucial for deglutition