Anatomy of the Pharynx

Anatomy

• The pharynx is a muscular tube that extends from the base of the skull to the cricoid cartilage (C6)
• It is divided into three parts:
  1. Nasopharynx: lies behind the nasal cavity and above the soft palate
  2. Oropharynx: lies behind the oral cavity and below the soft palate
  3. Laryngopharynx: lies behind the larynx and extends to the cricoid cartilage
• The pharynx is lined with mucous membrane and contains lymphoid tissue (e.g., tonsils and adenoids)

Functions

• Respiratory function: allows air to pass from the nasal and oral cavities to the larynx
• Digestive function: allows food to pass from the oral cavity to the esophagus
• Speech function: plays a role in the production of speech sounds
• Immune function: contains lymphoid tissue that helps to filter out pathogens and other foreign substances

Swallowing

• The pharynx plays a crucial role in the swallowing process
• Phases of swallowing:
  1. Oral phase: food is chewed and mixed with saliva in the oral cavity
  2. Pharyngeal phase: food is propelled through the pharynx by the tongue and the pharyngeal muscles
  3. Esophageal phase: food is propelled through the esophagus and into the stomach
• Swallowing reflex: a complex reflex that involves the coordination of multiple muscles and nerves to ensure safe and efficient passage of food and air through the pharynx

Anatomy of the Pharynx

• The pharynx is a muscular tube extending from the base of the skull to the cricoid cartilage (C6)
• It consists of three parts: nasopharynx, oropharynx, and laryngopharynx
• The nasopharynx lies behind the nasal cavity and above the soft palate
• The oropharynx lies behind the oral cavity and below the soft palate
• The laryngopharynx lies behind the larynx and extends to the cricoid cartilage
• The pharynx is lined with mucous membrane and contains lymphoid tissue, including tonsils and adenoids

Functions of the Pharynx

• The pharynx has a respiratory function, allowing air to pass from the nasal and oral cavities to the larynx
• It has a digestive function, allowing food to pass from the oral cavity to the esophagus
• The pharynx plays a role in the production of speech sounds
• It contains lymphoid tissue that helps filter out pathogens and other foreign substances, serving an immune function

The Pharynx in Swallowing

• The pharynx plays a crucial role in the swallowing process
• The oral phase of swallowing involves chewing and mixing food with saliva in the oral cavity
• The pharyngeal phase involves propelling food through the pharynx by the tongue and pharyngeal muscles
• The esophageal phase involves propelling food through the esophagus and into the stomach
• The swallowing reflex is a complex reflex that coordinates multiple muscles and nerves to ensure safe and efficient passage of food and air through the pharynx

Pharynx Anatomy

• The pharynx is a muscular tube located behind the nose and mouth, approximately 5 inches (13 cm) long.

Parts of the Pharynx

• The pharynx is divided into three parts: nasopharynx, oropharynx, and laryngopharynx.

Nasopharynx

• The nasopharynx is the upper part of the pharynx, extending from the base of the skull to the soft palate.
• It contains adenoids, which help fight infection.
• Nasal passages open into the nasopharynx.

Oropharynx

• The oropharynx is the middle part of the pharynx, extending from the soft palate to the hyoid bone.
• It contains the tonsils, which help fight infection.
• Mouth and nasal passages open into the oropharynx.

Laryngopharynx

• The laryngopharynx is the lower part of the pharynx, extending from the hyoid bone to the cricoid cartilage.
• It is a common passage for food and air.
• It leads to the esophagus and larynx.

Muscles of the Pharynx

• The pharynx has two types of muscles: intrinsic and extrinsic muscles.
• Intrinsic muscles, also known as constrictor muscles, help swallow food.
• Extrinsic muscles, also known as elevator muscles, help open the upper esophageal sphincter.

Blood Supply and Innervation

• The pharynx receives its arterial supply from the pharyngeal arteries, which branch from the external carotid artery.
• Venous drainage is via the pharyngeal veins to the internal jugular vein.
• The pharynx is innervated by the pharyngeal plexus of nerves.