Parotid Gland Disorders: Anatomy And Clinical Relevance

Parotid Gland Disorders: Anatomy And Clinical Relevance

Classify salivary glands and describe the parotid gland briefly.
Answer:

Classification of salivary glands:

1. Based on the size of the glands:

1. Major glands:
   1. Parotid gland
   2. Submandibular gland Sublingual gland
2. Minor glands:
   1. Glossopalatine.
   2. Palatine
   3. Von Ebner’s gland
   4. Labial and lingual gland Posterior lingual gland.

2. Based on the location of the glands:

• Labial glands
• Lingual glands.

3. Based on the nature of secretion:

1. Serous glands:
   • Parotid gland
   • Von Ebner’s gland
2. Mucous glands:
   • All minor glands except von Ebner’s gland.
3. Mixed.
   • Submandibular gland
   • Sublingual gland.

Parotid gland:

Anatomy:

• It is the largest major salivary gland.

Parotid gland Parts:

1. Superficial part.
   • Located subcutaneously in front of the external ear.
2. Deeper portion.
   • Lies behind the ramus of the mandible.

Parotid gland Size:

1. 5.8 cm craniocaudally.
2. 3.4 cm ventrodorsally.
   1. Weight: Between 14 and 28 grams.
   2. Duct: Stensen’s duct.
   3. Runs forward across the masseter muscle, and turns inward at the anterior border of the masseter.
   4. It opens into the oral cavity at a papilla opposite the maxillary second molar.
   5. Accessory gland:
   6. Located just anterior to the superficial portion of the parotid gland.

Blood supply:

• From branches of the external carotid artery.

Nerve supply:

• Parasympathetic nerve supply from the glossopharyngeal nerve.
• Preganglionic fibers synapse in the otic ganglion.
• Postganglionic fibers reach the gland through the auriculotemporal nerve.
• The sympathetic innervations from the superior cervical ganglion.

Nerve supply Histology:

• Secretory end prices are spherical and serious.
• Acinar cells.
• Pyramidal shaped.
• Have a basally situated nucleus
• The nucleus is surrounded by a small, central lumen.
• The basal cytoplasm is basophilic.
• Secretory granules are acidophilic.
• Fat cell spaces are seen.

Ducts:

• Intercalated duct.
• Numerous and long.
• Slightly acidophilic.
• Consist of a simple columnar epithelium with round, centrally placed nuclei.
• Faint striations representation infoldings and mitochondria may be visible below the nucleus.