Pharynx: Definition, Location, Function, Structure, Facts, Topics

Definition of the Pharynx

The pharynx is a muscular tube that is part of the throat connecting the mouth and nasal cavity to the larynx and esophagus. It acts as a passage into both digestive as well as the respiratory system. It participates in respiration, digestion, and immune defence.

Position of the Pharynx

The pharynx is the cavity located at the back of oral and nasal cavities. In the digestive system, the pharynx opens into the oesophagus while in the respiratory system, it leads into the larynx. Changes in form and structure may occur in different organisms in accordance. It may be thick and muscular in some and turned outward or rotated in others.

Anatomy and Regions of the Pharynx

The pharynx is divided into three related regions as follows:

Nasopharynx

• Uppermost part behind the nasal cavity that establishes the airway through the nose.

• Oropharynx joins the nasopharynx through an isthmus which makes respiration through the mouth possible.

Oropharynx

• Part behind the oral cavity

• Extends from the soft palate down to the level of the hyoid bone.

• Opens to the anterior using the mouth and posteriorly to the nasopharynx.

Laryngopharynx

• Lowermost part of the pharynx

• Extending from the epiglottis downwards to the oesophagus.

Musculature of the Pharynx

The pharynx contains both sets of muscles, longitudinal and circular, which by their contraction change the shape of its lumen.

Circular Muscles

• Push food downward by peristalsis.

Longitudinal Muscles

• Lift and widen pharynx during swallowing

General Features Of The Pharynx

Functional parts of such parts may be enumerated as follows:

Pharyngeal Tonsils (Adenoids)

• These are mucous membranes having lymphoid tissues along the wall of the nasopharynx, hence forming part of the immune host response.

Eustachian tubes

• Providing an anatomic equilibration of air pressure from the middle ears opening into the pharynx.

Epiglottis

• A flap of muscle closes the entrance to the pharynx from the larynx thereby preventing food from entering the trachea.

Waldeyer's Ring

• An obliquely oriented ring including the pharyngeal, tubal, palatine and lingual tonsils which work as a barrier against the micro-organisms which enter the body both by the digestive and respiratory tracts.

Functions of the Pharynx

The pharynx performs several important functions. For example, this structure acts as a:

• Passage for Air and Food: It allows the passage of air to the lungs and food to the oesophagus.

• Speech: It acts as a resonating chamber; sounds from the larynx are amplified in the pharynx.

• Immune Defence: Pharynx lymphoid tissues act as the first line of defence against many pathogens in the body.

• Warming and Humidifying Air: The air becomes warmed and humidified during its passage to the lungs.

• Deglutition: Circular and longitudinal muscles will push the food down by peristalsis. Longitudinal muscles lift and flare the walls for the food to pass through.

Disorders Of The Pharynx

Following are some common disorders of the pharynx:

Pharyngitis

• An infection that causes inflammation of the pharynx, whether viral or bacterial.

Tonsillitis

• The infected tonsils in those cases where infections cause all other irritation and trouble, including tenderness or difficulty in swallowing.

Pharyngeal Cancer

• A successive growth of cancerous tissue in the pharynx.

Sleep Apnea

• The most basic variety of blocked airflow in an individual happens during rest and is brought about by the collapsing of the pharynx.

Pharynx NEET MCQs (With Answers & Explanations)

Important questions asked in NEET from this topic are:

• Anatomy of the pharynx

• Disorders of the pharynx

Practice Questions for NEET

Q1. The nasopharynx is involved in

1. Breathing and speech

2. Breathing and digestion

3. Digestion and speech

4. Digestive process

Correct answer: 1) Breathing and speech

Explanation:

The nasopharynx is the superior subdivision. It lies superior to the soft palate and ends at the uvula. It is involved only in breathing and speech. It communicates laterally with the middle ear through the eustachian tube.

Hence, the correct answer is option 1) Breathing and speech.

Q2. Which of the following structures prevents the entry of food particles into the trachea during swallowing?

1. Glottis

2. Uvula

3. Epiglottis

4. Both a & c

Correct answer: 3) Epiglottis

Explanation:

The Glottis is the opening of the pharynx into the trachea and is always open during the process of respiration. The uvula is a soft muscular structure preventing the entry of food into the nasal cavity during swallowing. The Glottis is covered by a flap-like structure called epiglottis which helps prevent the food particles from moving into the trachea during swallowing instead of the food pipe.

Hence, the correct answer is option 3) Epiglottis.

Q3. Larynx consists of ________ cartilage.

1. 6

2. 3

3. 1

4. 9

Correct answer: 4) 9

Explanation:

The larynx, commonly known as the "sound box," plays a crucial role in the respiratory system as it is responsible for producing sound for speech. It is made up of nine cartilages, which include three unpaired and three paired cartilages. The unpaired cartilages consist of the thyroid cartilage, cricoid cartilage, and epiglottis. The paired cartilages include the arytenoid, corniculate, and cuneiform cartilages.

Hence, the correct answer is option 4) 9.

Also Read:

• MCQs on Pharynx

• Pancreas

• Intestinal Glands

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