Glands

• Glandular tissue


  Includes the lacrimal, salivary, thyroid, parathyroid, and thymus glands
• Gland


  A structure that produces a chemical secretion necessary for normal body functioning
• Exocrine gland


  Has a duct associated with it
• Endocrine gland


  Ductless gland, with the secretion being poured directly into the vascular system
• Lacrimal glands


  • Paired almond-shaped exocrine glands that secrete lacrimal fluid or tears
  • Lubricates the eye
  • Contains epithelial and lymphatic tissue
• Tear production and drainage

  1. Lacrimal gland

  2. Conjunctiva

  3. Lacrimal punctum

  4. Lacrimal sac

  5. Nasolacrimal duct

  6. Inferior nasal concha
• Lacrimal sac


  The duct can form a mucocoele or become clogged
• The lacrimal bone contains the duct which drains the eye, so when you cry your nose runs
• Lacrimal gland innervation


  • Parasympathetic fibers from the greater petrosal nerve (CN VII) provide efferent innervation
  • Preganglionic fibers synapse at the pterygopalatine ganglion, and postganglionic fibers join maxillary branches (V2) of the trigeminal nerve
  • The lacrimal nerve serves as an afferent nerve
• CN VII parasympathetic pathways

  • Lacrimal
  • Submandibular
  • Sublingual
  • Mucous membranes of nose, palate, oropharynx
• Lacrimal gland lymphatic drainage and blood supply


  • Drains into the superficial parotid lymph nodes
  • Supplied by the lacrimal artery, a branch of the ophthalmic artery of the internal carotid artery
  • Venous blood returns by way of the superior ophthalmic vein
• Dry eye syndrome (DES) or keratoconjunctivitis sicca (KCS)


  Persistent dryness, scratching, and burning in the eyes
• Saliva


  Immune system IgA, salivary amylase, lubricates and cleanses the oral cavity, helps in digestion, prevents decay, contains biomarkers/DNA
• Salivary glands


  Exocrine glands controlled by the autonomic nervous system (ANS)
• Major salivary glands


  • Parotid glands
  • Submandibular glands
  • Sublingual glands
• Parotid salivary gland


  • Largest encapsulated major salivary gland
  • Serous only
  • 25% of total volume
  • Has superficial and deep lobes
• Parotid duct or Stenson's duct


  Duct associated with the parotid salivary gland
• Parotid gland innervation


  • Efferent (parasympathetic) nerves of the CN IX or glossopharyngeal nerve by way of the lesser petrosal nerve to otic ganglion to join V3 auriculotemporal pathway
• Parotid gland lymphatic drainage and blood supply

  • Drains into the deep parotid lymph nodes
  • Supplied by branches of the external carotid artery, the transverse facial artery
  • Venous return is by the retromandibular vein
• Parotid gland pathology - Mumps


  Contagious viral infection usually involves inflammatory enlargement or parotitis of both glands, first one side and then the other, giving the characteristic "chipmunk" cheeks
• Parotid gland pathology - Cancer

  • Can change the consistency of the gland to bony hard
  • Can cause unilateral facial pain on the involved side because the seventh or facial cranial nerve travels through the gland
• 90% of all salivary gland cancers are parotid salivary gland cancers
• Submandibular salivary gland


  • Second largest encapsulated major salivary gland
  • Serous and Mucous
  • 60% to 65% of saliva production
• Submandibular duct or Wharton duct

  Duct associated with the submandibular salivary gland
• Submandibular gland innervation, lymphatic drainage, and blood supply

  • Innervated by efferent (parasympathetic) fibers of the chorda tympani CN VII
  • Drains into the submandibular lymph nodes
  • Supplied by branches of the facial and lingual arteries
  • Venous return is mainly by the facial vein
• Sublingual salivary gland


  • Smallest and only unencapsulated major salivary gland
  • 10% of total salivary volume
  • Serous and Mucous (mostly mucous)
• Sublingual gland innervation, lymphatic drainage, and blood supply


  • Same innervation as the submandibular salivary gland, CN VII (efferent parasympathetic) chorda tympani
  • Drains into the submandibular lymph nodes
  • Supplied by the sublingual and submental arteries, with venous return paralleling the arterial supply
• Minor salivary glands


  • Small and more numerous (600-1000) than major glands
  • 10% total salivary volume
  • Not encapsulated but surrounded by connective tissue within the submucosa
  • Exocrine, one short duct per gland
  • Innervation is based on location
• Von Ebner glands


  • Serous only glands at the base of the large circumvallate lingual papillae on the posterior dorsal surface
• Minor Salivary Glands


  • Small and more numerous (600-1000) than major glands
  • 10% total salivary volume
  • Not encapsulated but surrounded by connective tissue within the submucosa
  • Exocrine, one short duct per gland
  • Innervation is based on location
• Minor Salivary Glands in Circumvallate Papillae

  • Von Ebner glands at base of the large circumvallate lingual papillae on the posterior dorsal surface
  • Serous Only
• Minor Salivary Glands are mostly Mucous, some serous
• Salivary stone (or sialolith)

  Most common in submandibular gland
• Mucocele


  Often from lip biting, duct damage and gland fills with saliva. Surgical removal must be done carefully or more will be created
• Ranula


  Blocked major gland, floor of mouth
• Pleomorphic adenoma


  Slowly enlarging mass in the lower pole of the parotid salivary gland, but the appearance is not specific and any benign and some low-grade malignant neoplasms could appear the same
• Sjögren syndrome


  Bilateral parotid salivary gland enlargement, a systemic autoimmune disease in which immune cells attack and destroy the exocrine glands that produce tears and saliva
• Nicotinic stomatitis


  Hard palate is whitened by hyperkeratinization caused by the heat from tobacco use or hot liquid consumption
• Surgical removal of salivary glands for biopsy can be done if histological diagnosis needed
• Thyroid Gland


  • The largest endocrine gland
  • Secretes thyroxine directly into the vascular system
  • The gland consists of two lateral lobes, right and left, connected anteriorly by an isthmus
  • Moves with larynx during swallowing
  • Should feel symmetrical both sides