The Mouth Flashcards
What are the 3 overall processes occurring due to the mouth?
- Salivation
- Mastication (formation of a bolus)
- Swallowing
What epithelia line the tongue? What other mechanisms does the tongue have to perform its sensory and motor role?
Stratified squamous non keratinized
- Has dorsal papillae - some with taste buds
- Movement/Skeletal muscle: fibres oriented in multiple planes with the intrinsic muscles ingurgitating directly with the CT of the tongue
How much saliva do we produce a day? Name 3 of its general functions
- 5L
- Lubrication
- Starts digestion of carbs (amylase)
- Protects the oral environment (Contains many potent anti-bacterial substances)
Name 5 mechanisms saliva uses to protect the oral environment
- Keeps mucosa moist
- High calcium concentration washes and protects the teeth
- Maintaining a highly alkaline environment neutralizes the acid produced by bacteria
- Proteolytic enzymes (lysozyme, lactoperoxidase) attack/destroy the bacteria
- Secretory antibodies like IgA destroy some microbes in the mouth
What enzymes does each of the major salivary glands produce if any? What is the structure of each of the glands?
Parotid: a-amylase, acinar glands
Submandibular: a-amylase and lysozyme, tubuloacinar
Sublingual: purely mucous (no enzymes), tubuloacinar
What does the acinar secretion and ductal modification determine about the saliva?
Acinar secretion: determines the volume
Ductal modification: determines the composition
What is the primary role of ductal modification?
To make hypotonic saliva by reducing the [Na+]
What determines the [HCO3-] in the saliva?
Whether it is saliva at rest or saliva being produced when stimulated, when saliva is stimulated the [HCO3-] rises dramatically
What is the primary difference between resting and stimulated saliva? Name 3 characteristics of each
In stimulated, the saliva has to do more work and requires more enzymes. It is also needed much quicker so there is less time for modification:
Resting: low volume, very hypotonic (a lot of Na+ removed), neutral or slightly acid
Stimulated: high volume, less hypotonic (less time to remove Na+), more alkaline
What are the two main parasympathetic nerves that control salivary secretion? Which structures do they act upon?
CN IX Glossopharyngeal: Parotid via the otic ganglion
CN VII Facial: submandibular and sublingual
Where does the afferent information that inevitably triggers salivation come from?
Taste receptors in the mouth and tongue (especially stimulated by acid), the nose and conditioned reflexes all travel to the centres in the medulla via CN IX and VII
How does the efferent information affect salivation? What is the sympathetic and parasympathetic output?
Stimulates the acinar cells, the ductal cells to promote HCO3- secretion (so the [HCO3-] rises)
Sympathetic: reduces blood flow so the mouth is drier and saliva is thicker
Parasympathetic: the release of fluid secretions and increased bloodflow
What cell type surrounds the acini and helps saliva move towards the oral cavity
Myoepithelial cells
Name 4 muscles that aid in mastication and how they act on the mandible
- Masseter: elevates
- Temporalis: elevates and retracts
- Medial pterygoid: elevation and side-side movements
- Lateral pterygoid: protrusion and side-side movements
What innervates the mandible muscles?
The V3 mandibular nerve (branch of trigeminal (V) nerve) and the facial nerve VII
