Pharynx Anatomy

The pharynx is located at the base of the skull and ends at the lower border of the cricoid cartilage (C6). The pharynx is divided into three parts and its structure is divided into:

Internal Structure of Pharynx

The diagram of pharynx shows the internal structure comprising of following parts:

Nasopharynx

• The nasopharynx is the uppermost part of the pharynx, located behind the nasal cavity.
• It communicates with the nasal cavity through the posterior nasal apertures also called as choanae.
• The pharyngeal tonsils or adenoids are located on the posterior wall of the nasopharynx.
• The Eustachian tubes also called as auditory tubes open into the lateral walls of the nasopharynx, connecting it to the middle ear.

Oropharynx

• The oropharynx is the middle portion of the pharynx, situated behind the oral cavity.
• It extends from the soft palate to the level of the hyoid bone.
• The palatine tonsils are located in the lateral walls of the oropharynx.
• It serves as a common pathway for both food and air, as it is involved in swallowing and breathing.

Laryngopharynx

• The laryngopharynx is the lowermost part of the pharynx, situated behind the larynx.
• It extends from the hyoid bone to the level of the cricoid cartilage.
• The laryngopharynx is continuous with both the esophagus posteriorly and the larynx anteriorly.
• It moves food and air into their respective passages during swallowing.

Also Read: Difference Between Pharynx And Larynx 

External Structure of Pharynx

The pharynx consists of external parts such as:

Muscles

• Pharyngeal muscles are voluntary striated muscles spanning from the nasopharynx to the esophagus.
• They work together to propel food from the mouth to the esophagus, involving the superior, middle, and inferior constrictor muscles, along with the stylopharyngeus and palatopharyngeus muscles.
• These muscles, comprising the inner pharynx, also play a role in elevating the larynx, shortening the pharynx, and helping in swallowing and speech.

Blood Supply

• The blood supply to the pharynx comes from branches of the external carotid artery, including the ascending pharyngeal artery and branches from the facial and lingual arteries.
• The lower part of the pharynx receives blood supply from the inferior thyroid artery and superior thyroid artery. 
• The rest of the pharynx receives blood from the ascending palatine, tonsillar branches of the facial artery and maxillary artery.

Nerve Supply

• The vagus nerve (cranial nerve X) and the glossopharyngeal nerve (cranial nerve IX) supply the muscles of the pharynx. 
• The vagus nerve supplies all the muscles except the stylopharyngeus, which is supplied by the glossopharyngeal nerve.

Lymphatics

• The pharynx has an extensive network of lymphatic vessels and lymph nodes,
• They play a vital role in immune defense and drainage of lymphatic fluid from the head and neck region.

Also Read: Difference Between Esophagus And Trachea 

The diagram of pharynx helps us to understand its structure and function. The pharynx is a muscular tube in the throat that connects the mouth to the esophagus and the nose to the larynx. The simple diagram of pharynx shows its three main parts: nasopharynx, oropharynx, and laryngopharynx. The diagram of pharynx class 10 is important for examinations.

A well-labeled diagram of pharynx is given below: