VAN 221: Veterinary Splanchnology and Applied Anatomy (1+1)

PHARYNX ( OX )

Ox

• The pharynx is a musculo-membranous passage common to both the digestive and respiratory systems
• It is a funnel shaped organ, the broad end of which continuous with the mouth and nasal cavities, while the oesophagus continues the narrow portion
• It is directed obliquely downwards and backwards and is attached by muscles to the palatine, pterygoid and hyoid bones and to the cricoid and thyroid cartilages of larynx

Relations

• Dorsally the base of cranium and supra-pharyngeal lymph glands, and Ventrally the larynx, Laterally, the medial pterygoid muscles, great cornua of the hyoid bone, external carotid and external maxillary arteries, the glosso-pharyngeal, cranial laryngeal and hypoglossal nerves, mandibular salivary glands and para-pharyngeal lymph glands

The cavity of the pharynx presents seven openings

• One and two - Two caudal nares situated at the antero-dorsal part communicating with the nasal cavities
• Three - The Isthmus faucium below the caudal nares communicating with the mouth cavity
• Four - The auditus laryngis opening into the larynx
• Five - Auditus oesophagi opening into the oesophagus
• Six and Seven - Two Eustachian orifices behind the caudal nares at the dorso-caudal part communicating with the tympanic cavity of middle ear, through Eustachian tubes
• The vault or fornix on the roof of pharynx is divided here into two cul-de-sac by a median fold of mucous membrane., which is the continuation of the septum nasi
• Structure
  • Pharyngeal muscles
  • Aponeurosis - attached to the bones at the base of the cranium
  • Mucous membrane- continuous with that of the several cavities which opens into it