Mouth and swallowing Flashcards
What is the function of the hard palate?
To provide an ‘anvil’ against which the tongue can crush food.
Why are the canine teeth also known as cuspids?
They have a single root.
What function do the canines serve?
Tearing.
What function do the incisors serve?
Cutting.
What function do the premolars/molars serve?
Grinding.
Describe the roles of saliva.
Lubrication (of mouth and food) and cleaning
-Serous fluid, mucus
Facilitation of taste
Protection against acid and bacteria
-Antibacterial enzymes (e.g. lysozyme, IgA)
-Bicarbonate
-Calcium ions
Digestion
-Salivary amylase (ptyalin), lingual lipase
Describe the regulation of saliva production.
Almost entirely due to neural control
Both parasympathetic (watery) and sympathetic (mucoid) activity increase secretion
PS controlled by salivatory centre in the brain stem, driven by:
-Local stimuli (taste and touch in the mouth)
-Central stimuli (smell & sight of food, etc)
-(learned) reflex – think of Pavlov’s dogs
Describe saliva secretion.
Initial isotonic fluid, containing (mainly) NaCl, protein, and/or mucus
As it passes along the duct, salt reabsorption and HCO3- (and K+) secretion leads to a hypotonic, alkaline fluid.
Name the major salivary glands.
Parotid
Sublingual
Submandibular
Describe the innervation of the parotid gland.
Parasympathetic supply via CN IX (glossopharyngeal)
Sympathetic supply from superior cervical ganglion
Is the parotid gland predominantly serous or mucous?
Serous
What percentage volume of saliva is produced by the parotid?
25%
Describe the innervation of the submandibular gland.
Parasympathetic supply via CN VII (facial)
Sympathetic supply from superior cervical ganglion
Is the submandibular gland predominantly serous or mucous?
Mixture.
What percentage volume of saliva is produced by the submandibular?
70%
Describe the innervation of the sublingual gland.
Parasympathetic supply via CN VII (facial)
Sympathetic supply from superior cervical ganglion
Is the sublingual gland predominantly serous or mucous?
Mucous.
What percentage volume of saliva is produced by the sublingual?
5%
Which salivary gland is the predominant producer of amylase and proline-rich proteins?
Parotid?
Which salivary gland is the predominant producer of lysozyme and lactoperoxidase.
Submandibular.
Which salivary gland is the predominant producer of lingual lipase?
Sublingual.
What kind of linkages make up starch?
α-1,4 and α-1,6
At which site can α-amylase cut?
α-amylases can only cut at α-1,4 sites, and not adjacent to the α-1,6 sites
How does lingual lipase work?
Cleave the outer fatty acids off triglycerides, leaving diacyl glycerol.
Name the ion channel-based taste receptors.
Salty and sour.
Name the GPCR-based taste receptors.
Sweet, bitter and umami.
What is the cephalic phase?
The cephalic phase of gastric secretion occurs even before food enters the stomach, especially while it is being eaten. It results from the sight, smell, thought, or taste of food, and the greater the appetite, the more intense is the stimulation. Neurogenic signals that cause the cephalic phase of gastric secretion originate from the cerebral cortex and in the appetite centers of the amygdala and hypothalamus.They are transmitted through the dorsal motor nuclei of the vagi and then through the vagus nerve to the stomach. This phase of secretion normally accounts for about 20 percent of the gastric secretion associated with eating a meal.
