PAROTID GLAND

Parotid Gland

The parotid gland is a major salivary gland located in the face, responsible for producing saliva that helps in digestion and mouth hygiene. It is a compound gland, meaning it has both serous and mucous secretory units.

Surfaces, Borders, and Relations

• The parotid gland has three surfaces: anterior (in front), posterior (at the back), and inferior (below).
• Anterior surface: It lies over the masseter muscle and is covered by the skin.
• Posterior surface: It is in contact with the mastoid process of the temporal bone.
• Inferior surface: It is related to the digastric muscle and the styloid process.
• Borders:
  • Superficial border: It is marked by the zygomatic arch.
  • Deep border: It is in contact with the ramus of the mandible.
• Relations:
  • Above: The superficial temporal artery and vein.
  • Below: The digastric muscle and the styloid process.
  • Medially: The posterior belly of the digastric muscle and the styloid process.
  • Laterally: The external auditory meatus.

Blood and Nerve Supply

• Blood supply:
  • The parotid gland is supplied by the external carotid artery through its branches: the maxillary artery and the superficial temporal artery.
  • The gland also receives blood from the internal maxillary artery.
• Nerve supply:
  • The parotid gland is innervated by the glossopharyngeal nerve (cranial nerve IX).
  • The sympathetic fibers are supplied by the plexus present in the gland.

Structures Inside the Parotid Gland and Parotid Duct

• The parotid gland contains:
  • Serous secretory units: They are surrounded by myoepithelial cells.
  • Mucous secretory units: They are present in the interlobular ducts.
• The parotid duct (Stensen's duct) opens into the oral cavity on the buccal mucosa, opposite the upper second molar tooth.
• The parotid duct is about 5 cm long and 1 cm wide.
• The parotid duct is lined by a stratified epithelium.

Clinical Aspect

• The parotid gland is involved in several clinical conditions:
  • Parotitis: Inflammation of the gland.
  • Parotid tumor: Malignant or benign growths in the gland.
  • Sjögren's syndrome: An autoimmune disease that causes dry mouth.
  • Frey's syndrome: A condition caused by damage to the auriculotemporal nerve, leading to excessive sweating and flushing in the affected area.