QS Study

The pharynx is a wide muscular tube situated behind the nose, the mouth and the larynx. It is a part of the upper respiratory tract. It is a five-inch-long tube that starts near our nose and ends at our windpipe. It receives food and air from the mouth, and air from the nasal cavities.

Blood Supply –

Arterial supply: The arteries supplying the pharynx are –

  1. Ascending pharyngeal branch of the external carotid artery.
  2. Ascending palatine and tonsillar branches of the facial artery.
  3. Dorsal lingual branches of the lingual artery.
  4. Greater palatine, pharyngeal and pterygoid branches of the maxillary artery.

Venous drainage: The veins form a plexus on the posterolateral aspect of the pharynx which drains into the internal jugular and facial veins. Venous drainage is achieved by the pharyngeal venous plexus, which drains into the internal jugular vein. The pharyngeal plexus is responsible for the venous drainage of the entire region.

  • Pterygoid venous plexus
  • Facial vein
  • Internal Jugular Vein.

Blood Supply of Pharynx 1

Fig: Blood Supply of Pharynx

Nerve supply

(A) Motor supply:

(a) All of the muscle except stylopharyngeus.

– supplied by cranial part of the accessory nerve, via the branch of the vagus to pharyngeal plexus.

(b) Stylopharyngeus – by glossopharyngeal nerve.

(B) Sensory supply:

  1. Nasopharynx – by maxillary nerve,
  2. Oropharynx – by glossopharyngeal nerve,
  3. Laryngopharynx – by an Internal laryngeal nerve.

Motor fibers are derived from the cranial accessory nerve through the branches of the vagus, supply all muscles of pharynx except stylopharyngeus which is supplied by the glossopharyngeal nerve.

Sensory fibers from the pharynx mostly pass through the glossopharyngeal nerve and partly by the vagus nerve. Taste sensations pass through the internal laryngeal branch of the vagus. The parasympathetic secretomotor fibers are derived from the greater petrosal nerve.

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