Saliva

Question 1

3 functions of saliva

Answer 1

• Lubricant for mastication
• Maintaining oral pH: needs to be maintained at about pH 7.4 (slightly alkaline) this is achieved by the bicarbonate/carbonate buffer system for the rapid neutralisation of acid
• Release digestive enzyme - salivary alphaamylase is released from the parotid gland for starch digestion

Question 2

how much saliva do adults secrete everyday

Answer 2

Daily secretion = 800 -1500ml in adults

Question 3

what does pH of saliva range between

Answer 3

pH ranges from 6.2 to 7.4

Question 4

what is Serous secretion

Answer 4

alpha amylase for starch digestion

Question 5

what is Mucous secretion

Answer 5

mucins for lubrication of mucosal surfaces

Question 6

is the parotid gland serous or mucous

Answer 6

serousb

Question 7

Submandibular gland serous or mucous

Answer 7

mucous & serous (M for mandibular AND for mixed secretions)

Question 8

Sublingual glands serous or mucous

Answer 8

mucous & serous - but mainly mucous

Question 9

Are minor glands serous or mucous

Answer 9

Minor glands are predominantly mucous but SOME are serous

Question 10

Factors affecting the composition & amount of saliva produced (9)

Answer 10

• Flow rate
• Circadian rhythm (sleep cycle)
• Type & size of gland
• Duration and type of stimulus that causes saliva to be produced
• Diet
• Drugs
• Age
• Gender
• Time of day

Question 11

Defences of the oral cavity are provided by (3)

Answer 11

• The mucosa - physical barrier
• Salivary glands - saliva washes away food particles which bacteria or viruses may use as metabolic support
• Palatine tonsils - act as the “surveillance system” for the immune system

Question 12

What are the salivary glands surrounded by

Answer 12

Salivary glands are surrounded by lymphatic system (linked to thoracic duct and blood) - which contains a broad range of functional immune cells

Question 13

What glands are always active

Answer 13

Submandibular, sublingual & minor glands are CONTINUOUSLY active

Question 14

Unstimulated components of the salivary system are dominated by

Answer 14

submandibular components

Question 15

dp parotid glands become the main source of saliva ?

Answer 15

Parotid glandONLY becomes main source of saliva when STIMULATED

Question 16

Three major pairs of salivary glands, contribute to 80% of salivary flow:

Answer 16

• Parotid
• Submandibular
• Sublingual

Question 17

-Minor salivary glands contribute to 20% of salivary flow - they are found in the

Answer 17

submucosa or the oral mucosa of the lips, cheeks, hard & soft plate and thetongue

Question 18

The parotid gland has a Superficial triangular outline between:

Answer 18

• Zygomatic arch
• Sternocleidomastoid
• Ramus of mandible

Question 19

Parotid duct Also called Stenson’s duct - enters the oral cavity how

Answer 19

crosses masseter muscle and pierces through the buccinator muscle where it enters the oral cavity near the second upper molar

Question 20

Where can the parotid duct be palpated

Answer 20

Can be palpated a fingers breadth below the zygomatic arch

Question 21

Sympathetic sensory innervation of the parotid gland

Answer 21

Sympathetic sensory innervation (inhibits/minimises secretion) is provided by the auriculo-temporal nerve which is a branch of the mandibular nerve (V3 - this division of the trigeminal nerve exits the skull through the foramen ovale)

Question 22

parasympathetic innervation of the parotid gland

Answer 22

Parasympathetic innervation is supplied by glossopharyngeal nerve (IX) - stimulates secretion

Question 23

Structures passing through the parotid:

Answer 23

• External carotid artery
• Retromandibular vein
• Facial nerve (VII - exits skull through the stylomastoid foramen) - supplies the muscles of facial expression

Question 24

What are the parotid glands made of

Answer 24

The parotid glands are entirely made up of serous acini with ducts interspersed

Question 25

How is the submandibular gland arranged

Answer 25

Two lobes separated by mylohyoid muscle - larger superficial lobeand a smaller deeplobe in the floor of the mouth

Question 26

How does the submandibular duct enter the oral cavity

Answer 26

The submandibular duct (Whartons duct) begins in the superficial lobe, wraps around the free posterior border of the mylohyoid, then runs along the floor of the mouth and empties into the oral cavity at the sublingual papillae - located more posteriorly than the sublingual gland`

Question 27

What is whartons duct

Answer 27

submandibular duct

Question 28

stensons duct

Answer 28

the parotid duct

Question 29

Sympathetic innervation of submandibular gland

Answer 29

is supplied via the lingual nerve which is derived from the facial nerve (VII)

Question 30

Parasympathetic innervation of submandibular gland

Answer 30

is supplied by the chorda tympani branch of the facial nerve (VII)

Question 31

how are the sublingual glands located in comparison to the submandibular glands

Answer 31

located more anteriorly than the submandibular glands

Question 32

where is the sublingual gland located

Answer 32

Located in the floor of the mouth between mylohyoid muscles and oral mucosa of floor of mouth

Question 33

How is the saliva transmitted to the oral cavity from the sublingual gland

Answer 33

Saliva is transmitted via the submandibular/ whartons duct as well or small ducts that pierce oral mucosa floor of mouth

Question 34

Which one is smaller sublingual or submandibular

Answer 34

sublingual is Much smaller than submandibular - but size is variable

Question 35

sympathetic innervation of sublingual gland

Answer 35

Sympathetic innervation is supplied via the lingual nerve which is derived from the facial nerve (VII)

Question 36

Parasympathetic innervation of sublingual gland

Answer 36

Parasympathetic innervation is supplied by the chorda tympani branch of the facial nerve (VII)

Question 37

Where are the minor salivary glands concentrated

Answer 37

Concentrated in the; buccal labial, palatal & lingual regions Also found at; superior pole of tonsils (Weber’s glands), tonsillar pillars & at the base of the tongue (von Ebner’s glands - underlying circumvallate papillae)

Question 38

Are minor salivary glands mucous or serous

Answer 38

Allminor salivary glands are mucous EXCEPT for the serous glands of von Ebner

Question 39

How do the minor salivary glands secrete saliva

Answer 39

They lack a branching network of draining ducts so each salivary unit has its own simple duct

Question 40

sympathetic innervation of minor salivary glands

Answer 40

inhibits salivary secretion (but some baseline secretion)

Question 41

parasympathetic innervation of minor salivary glands

Answer 41

stimulates salivary secretion

Question 42

what is Xerostomia and why does it happen

Answer 42

dry mouth - May be a consequence of cystic fibrosis or Sjorgren’s syndrome (autoimmune condition where immune cells attack glands resulting in little or no saliva produced - affects mainly women) - Most common causes - medication and irradiation for head and neck cancers

Question 43

what is obstruction of the salivary glands and where does it most commonly occur

Answer 43

- Saliva contains calcium & phosphate ions that can from salivary calculi (stones) - Most common in submandibular gland (80% incidence) - they block the duct at the bend around the round mylohyoid or at exit at the sublingual papillae

Question 44

causes of gland inflammation

Answer 44

- Caused by infection secondaryto obstruction | - Infections caused by; mumps (viral infection) - results in fever, malaise, swelling of the glands

Question 45

Why can degeneration of the salivary glands happen

Answer 45

Complication of radiotherapy to head and neck for cancer treatment

Question 46

what is Sjorgren’s syndrome who does it affect

Answer 46

autoimmune condition where immune cells attack glands resulting in little or no saliva produced mainly in post-menopausal females, also affects lacrimal glands (tears)

Question 47

what are the Effects of salivary gland dysfunction

Answer 47

-If salivary output falls to less than 50% of normal flow = Xerostomia (dry mouth): •Low lubrication - oral function becomes difficult •Low natural oral hygiene - poor pH control = accumulation of plaque = dental caries or increases incidence of opportunistic infections especially fungale.g candida - thrush