lecture 5 - salivary glands

what is a gland

a structure that produces a chemical secretion necessary for normal bodily functions

glandular tissue in the head and neck includes

• lacrimal - tear

• salivary - saliva

• thyroid

• parathyroid - regulate calcium and phosphorus 

• thymus

classification of glands

exocrine and endocrine 

exocrine gland has what associated with  

gland that has a duct associated with it 

exocrine produces what

produces substances (not hormones) that are released through ducts to the exterior of your body, like sweat, saliva, and tears

exocrine passageway allows for the secretion to be…

emptied directly into the location where the secretion is being used

(ex, salivary, lacrimal, sebaceous)

endocrine glands produce 

hormones and release them into your bloodstream 

(ex- adrenal, thyroid, hypothalamus)

are salivary glands are exocrine or endocrine

exocrine gland

salivary glands produce

saliva

salivary gland are controlled

by automatic nervous system, acts unconsciously

saliva is 

a watery secretion with a stable pH of around 7

saliva plays an important role in

bolstering and maintaining the health of oral soft and hard tissues

what saliva is made of

• salivary amylase

• lingual lipase

• mucus

• lysozyme

• immunoglobulin A

• electrolytes

salivary amylase in saliva 

an enzyme that begins starch digestions in the mouth 

lingual lipase of salvia

an enzyme that is activated by stomach acid and digests fat after the food is swallowed

mucus of saliva

binds and lubricates the food mass and aids in swallowing

Lysozyme of saliva

an enzyme that kills bacteria and other pathogens

immunoglobulin of saliva 

an antibody that inhibits bacterial growth 

electrolytes of saliva

including sodium, potassium, chloride, phosphate, and bicarbonate ions

function of saliva

• prepare the bolus of food for easier swallowing

• keep the mucous membranes lubricated

• prevent dehydration; dry mouth stimulus to drink water

• pH buffer

• breaks down starches

• cleanses teeth

• neutralizes acids to prevent tooth decay

• aids in taste

development of a salivary gland

• arise from a cord of epithelium 

• grows to form a tube 

• end of tube either round or tubelike clusters

• acini - cluster of secretory cells forms at the end of the tube 

what are acini

• secretory end pieces

• secrete proteins

• 3 kinds of acinar cells

what are the 3 kinds of acinar cells

• serous acini

• mucous acini

• seromucous acini

serous secretions 

• secretion is thinner and more watery

• less vicous

• no mucins

• primary source our amylase in saliva 

mucous secretion

• secretion is slightly viscous

• 99% water

• inorganic ions

• minor amount of amylase

• has mucins - key characteristic is their ability to from gels

seromucous secretions

has characteristics of both serous and mucous secretions

salivary glands are divided by size 

major and minor glands 

major and minor salivary glands are both

exocrine glands and thus have ducts associated with them

major and minor salivary glands function

help drain the saliva directly into the oral cavity where saliva can function

major salivary glands are

large paired glands and have named ducts associated with them 

what are the 3 major salivary glands

• parotid glands

• submandibular glands

• sublingual glands

parotid salivary gland info

• is the largest encapsulated major salivary gland

• divided into 2 lobes, superficial and deep lobes

• produces 25% saliva

• serous secretions

• innervated by fifth and ninth cranial nerves

parotid salivary gland location

occupies the parotid space, an area posterior to the mandibular ramus, anterior and inferior to the ear

parotid salivary gland ducts

• parotid duct or Stenson’s duct

• opens at parotid papilla - opposite maxillary second molar

parotid gland pathology - mumps

• gland becomes enlarged and tender when patient has mumps

• “chipmunk cheeks”

parotits

inflammatory enlargement of both glands 

submandibular salivary gland info

• second largest encapsulated major salivary gland

• produces 60-65% of saliva

• mucous and serous secretions

• posterior to sublingual gland

• wraps around the mylohyoid muscle

submandibular salivary gland location

occupies submandibular fossa in the submandibular space, mainly in its posterior part 

submandibular salivary gland ducts

• submandibular duct or Wharton’s duct 

• travels along anterior floor of the mouth then opens into sublingual caruncle

submandibular salivary gland innervated by 

VII cranial nerve 

sublingual salivary gland info

• smallest

• most diffuse

• only unencapsulated

• 10% total salivary volume

• mix of serous and mucous secretion

sublingual salivary gland location

occupies the sublingual fossa, near canines

sublingual salivary gland ducts

• sublingual duct or Bartholin’s duct

  • opens directly into the oral cavity 

• Ducts of Rivinus

  • along the sublingual fold

sublingual salivary gland innervated by

VII cranial nerve

Minor salivary glands are

• smaller than the larger major salivary glands

• more numerous in number

• von Enber’s glands

Minor salivary glands location

• found in buccal mucosa, labial mucosa, lingual mucosa, soft palate, posterior part of the lateral zones of hard palate, floor of mouth

• von Enber’s glands - on circumvallate papillae 

• lesser in number on tonsils, supraglottis region, paranasal sinuses, and between muscle gibers

Minor salivary glands ducts 

each minor salivary gland has a single duct directly into oral cavity

all minor salivary gland have a mucous secretion EXCEPT

for the glands of von Ebner which have a mainly serous secretion

minor salivary gland innervation

innervated by various nerves

salivary gland pathology - lesions

• salivary gland may become enlarged, tender, and firmer

• may form salivary stone within gland

• major glands with a ranula or minor glands with a mucocele

• uncomfortable but not dangerous 

ranula

salivary stone on floor of the mouth

mucocele

salivary stone can occur anywhere in the oral cavity, most common on the lips, inner cheeks, and floor of the mouth

sialolith 

salivary stone

sialolithiasis

when salivary stone becomes lodged within the duct causing a blockage of saliva

xerostomia

may result in hyposalivation, which reduces production of saliva , dry mouth

treatment for dry mouth

• good oral hygiene 

• fluoride treatment

• drink water