Salivary Glands

1
Salivary Glands

• Major salivary glands
• Lie at some distance from the mucosa and
  communicate with one or more ducts.
• Three paired masses of the parotid,
  submandibular, and sublingual glands.
• Minor Salivary glands
• Lie in the mucosa or submucosa and open directly
  or indirectly via many short excretory ducts.

2
Salivary Glands

• Function
• Lubrication of food, assisting swallowing.
• Moistening of the buccal mucosa, essential for
  speech.
• Provision of an aqueous solvent, necessary for
  taste.
• Provision of a fluid seal, necessary for sucking.
• Secretion of digestive enzymes, amylase.
• Secretion of hormones, Glucagons-like protein and
  ? serotonin

3
Salivary Glands
The Parotid gland

• The Parotid gland
• The largest of the salivary and is predominantly
  serous with few scattered mucous acini.
• It lies below the external auditory meatus in a
  deep hollow between the ramus, the mastoid and
  the styloid process.

4
Salivary Glands
The Parotid gland

• It is roughly wedge shape, with an upper and
  lower poles with the base above and the apex
  below behind the angle of the mandible.
• It is also wedge shaped in the horizontal plan
  with three surfaces, lateral, antero-medial and
  postero-medial, the base is the lateral and apex
  lies against the pharyngeal wall

5
Salivary Glands
The Parotid gland

• The parotid sheath
• is a tough capsule, derived from the investing
  layer of the deep cervical fascia
• Superficial layer is attached to the zygomatic
  arch
• The deep part to the styloid process, the
  mandible (stylo-mandibular ligament) and the
  tympanic part of temporal bone

6
Salivary Glands
The Parotid gland

• The upper pole
• adhere to the cartilage of external auditory and
  the TMJ capsule
• The lower pole
• is rounded and lie below and behind the angle of
  the mandible.
• The facial nerve
• divide it into superficial and deep parts or lobes

7
Salivary Glands
The Parotid gland

• Lateral surface
• is flat and covered with skin and superficial
  fascia containing great auricular nerve.
• Lymph nodes lie within the substance or under
  the sheath.
• The duct and the five branches of the facial
  nerve emerge from its anterior border

8
Salivary Glands
The Parotid gland

• Anteromedial surface
• U-shaped clasping the posterior border of the
  ramus with masseter laterally and medial
  pterygoid medially and inferiorly, separated by
  the stylomandibular ligament from the
  submandibular salivary gland

9
Salivary Glands
The Parotid gland

• The posteromedial surface
• Indented by the mastoid process and its muscles
• Lie against the styloid process with its three
  muscles and two ligaments
• The accessory gland
• Lies on the masseter between the duct and the
  zygomatic arch

10
Salivary Glands
Parotid gland

• The Parotid duct
• Emerge from the convex anterior border of the
  superficial part and pass anteriorly over the
  masseter muscle.
• At the anterior border of the muscle it turn
  medial and pierce the buccal pad fat and
  buccinator muscle, pass for a short distance
  under the mucous membrane before it opens
  opposite the upper second molar

11
Salivary Glands
Parotid gland

• Structures within the gland
• Facial nerve
• enter the gland from the deep surface and emerge
  from behind the anterior border.
• Retromandibular vein
• Deep to the branches of the nerve

12
Salivary Glands Parotid gland

• The capsule
• Derived from the deep cervical fascia which split
  at the lower pole to encase the gland
• The deep layer pass beneath the gland and ie
  attached to the skull base
• Part is inserted to styloid process and angle of
  mandible is thickened, stylomandibular ligament
  separating the gland from the submandibular one
• The superficial layer pass anterior on the
  masseter muscle and is attached to the lower
  border of the zygomatic arch
• Tight insertion will lead to sever pain on
  inflammation and swelling of parotid

13
Salivary Glands
Parotid gland

• External carotid artery
• With its two terminal branches it is the deepest
  structure
• Periauricular lymph nodes
• Lies within the gland or under the capsule

14
Salivary Glands
Parotid gland

• Blood supply
• External carotid artery and retomandibular vein
• Nerve supply
• Secretomotor fibres
• from the inferior salivary nucleus to the
  glossopharyngeal nerve, tympanic branch, tympanic
  plexus, lesser superficial petrosal to otic
  ganglion, to the Auriculotemporal nerve
• Sympathetic fibres
• From the superior cervical plexus
• Vasoconstrictor
• Sensory fibres
• Gland, auriculotemporal
• Capsule, greater auricular (C2)

15
Salivary Glands Parotid gland

• The capsule send septa to the interior of the
  gland separating it into lobules and making
  surgical removal difficult.
• Submandibular gland is loosely enveloped and can
  be shelled out easily
• Medially, the capsule is closely related to the
  pharynx and the great vessels in the carotid
  sheath
• Break through by tumour or sharp instrument