A funnel-shaped muscular tube about 12 to 14 cm long, shared by the airway and the food passage, ending at the cricoid cartilage
Pharynx — the throat, running from the skull base to C6.
Anatomy · Organs & viscera
Pharynx
About 12 to 14 cm long
Head and neck · digestive and respiratory systems
The pharynx, or throat, is the muscular funnel about 12 to 14 cm long that runs from the base of the skull to the level of the sixth cervical vertebra, where it becomes the oesophagus. It is a shared passage for air and food, divided into three parts: the nasopharynx behind the nose, the oropharynx behind the mouth and the laryngopharynx behind the larynx. Its wall is made of three overlapping constrictor muscles that propel food downwards.
How to spot them
- ▸A muscular tube behind the nasal cavity, mouth and larynx, in front of the cervical vertebrae
- ▸Three parts from top to bottom: nasopharynx, oropharynx and laryngopharynx (hypopharynx)
- ▸The soft palate separates the nasopharynx from the oropharynx; the epiglottis marks the change to the laryngopharynx
- ▸Three constrictor muscles (superior, middle and inferior) overlap like stacked flowerpots
What to know
Its highest part lies behind the nose and contains the adenoids and the openings of the Eustachian tubes
The nasopharynx, the upper part of the pharynx.
A ring of lymphoid tissue including the adenoids, tubal tonsils, palatine tonsils and lingual tonsil, named after a German anatomist
Waldeyer's ring, in the pharynx.
Its walls contain three constrictor muscles that overlap like stacked cups, the lower ones overlapping the upper
The superior, middle and inferior pharyngeal constrictors.
The pear-shaped recesses on either side of the laryngeal inlet where a fish bone often lodges
The piriform fossae, in the laryngopharynx.
A gap between two parts of the lowest constrictor muscle where a pouch may protrude, causing regurgitation of food
Killian's dehiscence and Zenker's diverticulum of the pharynx.
A groove, the fossa of Rosenmüller, behind the tubal opening is a common site of a tumour in southern Chinese populations
The pharyngeal recess of the nasopharynx, a site of nasopharyngeal carcinoma.
Key ideas
- During swallowing, the soft palate lifts to shut off the nose, the larynx rises and the epiglottis tilts to protect the airway, and the constrictors squeeze the food bolus down.
- The pharynx is the crossing point of the respiratory and digestive tracts, which is why food can go the wrong way and cause choking.
Quick-fire facts
- •It extends from the base of the skull to the lower border of the cricoid cartilage at C6, where it continues as the oesophagus.
- •The three parts are nasopharynx, oropharynx and laryngopharynx (hypopharynx).
- •All pharyngeal muscles are supplied by the vagus nerve via the pharyngeal plexus, except stylopharyngeus, which is supplied by the glossopharyngeal nerve.
- •The auditory (Eustachian) tube opens into the nasopharynx and equalises pressure in the middle ear.
- •The pharyngeal tonsil (adenoids) sits in the roof of the nasopharynx; the palatine tonsils are in the oropharynx.
- •The gag reflex is carried by the glossopharyngeal nerve (afferent) and vagus nerve (efferent).
- •The pharynx lies in front of the prevertebral fascia and the upper cervical vertebrae, and the retropharyngeal space lies between.
- •The inferior constrictor has two parts, thyropharyngeus and cricopharyngeus; the latter forms the upper oesophageal sphincter.
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Sources
- TeachMeAnatomy — The Pharynx
- OpenStax — The Mouth, Pharynx, and Esophagus (Anatomy and Physiology 2e, section 23.3)