Ingestion Of A Meal

Question 1

What muscles are used in closing the mouth?

Answer 1

Temporalis and massester

Question 2

Describe the temporalis muscle

Answer 2

Arises from the temporal fossa and inserts onto the coronoid process of the mandible

Question 3

Describe the masseter

Answer 3

Arises from the zygomatic process of the maxilla and inserts into the angle and ramus of the mandible

Question 4

Which muscles open the mouth?

Answer 4

Lateral pterygoid, digastric and infrahyoid

Question 5

Describe the lateral pterygoid

Answer 5

Arises from the sphenoid and inserts onto the condyloid process of the mandible

Question 6

Describe the digastric muscle of mastication?

Answer 6

Posterior; arises from the mastoid notch
Anterior; arises from the lower border of the mandible
Inserts onto the hyoid

Question 7

Describe the infrahyoid muscles of mastication

Answer 7

4 pairs of muscles, arise from hyoid and insert onto clavicle

Question 8

What controls mastication?

Answer 8

Brain stem pattern generator
Fine tuning via sensory feedback through periodontal ligaments and proprioceptors
Change in occlusion will change chewing pattern

Question 9

What are the 3 movements of mastication?

Answer 9

The temperomandibular joint (TMJ) allows three movements of mastication: open/close; protrusion/retraction; lateral

Question 10

What activates salivation?

Answer 10

Mastication, taste, smell, anticipation

Question 11

What inhibits salivation ?

Answer 11

Fear

Question 12

Where are salivary nuclei activated?

Answer 12

Superior (pons)

Question 13

Where are salivary nuclei inhibited?

Answer 13

Inferior ( medulla )

Question 14

Which salivary glands are activated and by what carnival nerve?

Answer 14

Submandibular sublingual salivary glands activated by cranial nerve VII

Question 15

Which salivary glands are inhibited and by what cranial nerve?

Answer 15

Parotid by cranial nerve IX

Question 16

What are the functions of saliva?

Answer 16

Tooth maintenance
Lubrication: allows speech, mastication and deglutition
Antibacterial/antifungal
Digestive; salivary amylase; lingual lipase

Question 17

What are the muscles of mastication innervated by?

Answer 17

The mandibular branch of the trigeminal nerve

Question 18

What control are the muscles that move the mandible under?

Answer 18

Voluntary

Question 19

What are the reflexes of the jaw?

Answer 19

Jaw unloading reflex and jaw jerk reflex

Question 20

What are the main functions of saliva in preserving the teeth?

Answer 20

Dilution, clearance and buffering

Question 21

What happens on the Stephan curve?

Answer 21

Plaque pH plummets from 7 to about 5 before climbing back up - sugar had been added
ph less than 5.5 teeth demineralise due to acid produced by bacteria
Saliva dilutes the sugar
Clear it by swallowing
Saliva has bicarbonate in it to neutralise the acid

Question 22

How does saliva lubricate?

Answer 22

Salivary glycoproteins are sticky and move freely in a plane rubbing over each other side to send, but don’t move upwards
Make a thin film to coat all oral surfaces and food

Question 23

Describe the oral/buccal phase of deglutition?

Answer 23

Voluntary
The bolus is pushed to the back of the mouth by the tongue
The teeth are brought together
The soft palate elevated to close the nasal cavity
The larynx rises to close the airways
(Inspiration is inhibited)

Question 24

Describe the pharyngeal stage of deglutition

Answer 24

Involuntary (reflex)
cricopharyngeal sphincter relaxes to open the oesophagus
The epiglottis steers the bolus over the trachea and the peristalsis starts

Question 25

Describe the oesophageal phase of deglutition

Answer 25

Peristalsis takes food down towards the stomach | All of changes in the oral / buccal and pharyngeal phases reverse

Question 26

What is the function of amylase?

Answer 26

Breaks down starch

Question 27

How is saliva antibacterial/antifungal?

Answer 27

Protection barrier Secretory IgA Lysozyme

Question 28

How many pairs on salivary glands are there and what are they called?

Answer 28

3 pairs Parotid - biggest by ear Submandibular - under and further back from tongue Sublingual - under the tongue

Question 29

What type of saliva do parotid glands produce?

Answer 29

Serous

Question 30

What type of saliva do sublingual glands produce?

Answer 30

Mucous | Good for giving resting saliva

Question 31

What type of saliva do submandibular glands produce?

Answer 31

Mixed serous and mucous

Question 32

What type of saliva do minor glands produce?

Answer 32

Mucous

Question 33

What do all salivary glands secrete?

Answer 33

Both protein and fluid

Question 34

What is the consistency of saliva determined by?

Answer 34

The nature of the secreted protein

Question 35

What are the cells that produce saliva called?

Answer 35

Acinar cells

Question 36

What are the 2 types of acinus cells?

Answer 36

Serous acinus and mucous acinus

Question 37

Why does Mucinus acinus stain more heavily than serous acinus cells?

Answer 37

Has more glycoprotein

Question 38

What does saliva produced by acinus cells pass down?

Answer 38

Intercalated duct Striated duct Excretory duct

Question 39

Where is the nucleus located in acinar cells?

Answer 39

Basolateral or blood side

Question 40

What does the acinar contain?

Answer 40

Nucleus, endoplasmic reticulum, secretory vesicles

Question 41

What 2 things do you need for saliva?

Answer 41

Protein and fluid

Question 42

What is the secretion of protein in saliva regulated by?

Answer 42

Secondary messenger cAMP cyclic adenosine monophosohate

Question 43

What is fluid secretion in saliva regulated by?

Answer 43

Calcium

Question 44

What regulates cAMP production?

Answer 44

Sympathetic nervous system | Noradrenalin

Question 45

What regulates Ca2+ secretion

Answer 45

Parasympathetic nervous system | Acetylcholine

Question 46

What happens when noradrenaline binds to the beta adrenergic receptor?

Answer 46

Activates receptor Activated receptor activates alpha subunit of G protein which then activates adenylate cyclase Adenylate cyclase takes ATP and turns it into cyclic AMP

Question 47

What does cyclic AMP do in acinar cells?

Answer 47

Diffuses into the nucleus where it switches on protein transcription Causes maturation of the proteins and the formation of secretory vesicles Stimulates exocytosis in acinar cells

Question 48

How does IgA get from the blood to the saliva?

Answer 48

Receptors for IgA on the basolateral membrane Bind the IgA IgA is internalised and crosses the cell in the vesicles then exocytose off in the apical membrane

Question 49

What receptor does IgA bind to?

Answer 49

Polymeric immunoglobulin receptor | PIgR

Question 50

What receptor is involved in fluid secretion?

Answer 50

M3 muscarinic receptor

Question 51

What happens when M3 muscarinic receptor is activated?

Answer 51

Activated by acetylcholine Causes activation of phospholipase C Phospholipase C makes IP3

Question 52

What does IP3 do?

Answer 52

Releases calcium from the endoplasmic reticulum Ca2+ increases in acinar cells Ca2+ depended ion channels on membrane Apical - chloride and basolateral K+ move out of cell Creates charge imbalance across tissue Drags sodium between cells Moves salt from basolateral side to to apical side Creates and osmotic gradient Moved fluid

Question 53

What happens if salivary glands aren’t working?

Answer 53

Opportunistic infections eg Candida infection | Rampant caries

Question 54

What is xerostomia?

Answer 54

Dry mouth

Question 55

What causes xerostomia?

Answer 55

Analgesics Anti hypertensives Anti depressants Anti histamines