Mouth and Swallowing Flashcards
What are the 4 roles of saliva?
Lubrication (of mouth and food) and cleaning
Facilitation of taste
Protection against acid and bacteria
Digestion
Which autonomic nervous system type activates secretion of watery saliva?
Parasympathetic
Which autonomic nervous system type activates secretion of mucoid saliva?
Sympathetic
What three factors is the 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)
In a ‘salivon’ what does the initial isotonic fluid mainly contain?
NaCl, protein and/or mucus
As the initial isotonic fluid passes along the duct, salt reabsorption and HCO3- (and K+) secretion leads to what?
A hypotonic, alkaline fluid
The major salivary glands are the sublingual gland, the submandibular gland and which other?
Parotid gland
As the largest salivary gland, the parotid gland accounts for what percentage of salivary volume?
about 25%
What type of secretion does the parotid gland predominantly secrete?
Serous secretion
The parotid gland is the main source of what?
Salivary amylase and proline-rich proteins
The parotid gland receives ________supply via CN IX (glossopharyngeal) and
________ supply from the superior cervical ganglion.
Parasympathetic - CN IX (glossopharyngeal)
Sympathetic - superior cervical ganglion
What percentage of salivary volume does the submandibular gland account for?
about 70%
What is the submandibular gland the main source of?
Lysozyme and lactoperoxidase
Which nerve provides parasympathetic supply to the submandibular gland?
CN VII (facial)
What type of secretion does the sublingual gland predominantly secrete?
mucous
What is the sublingual gland the main source of?
lingual lipase
At what pH are a-amylases denatured?
4
Which sites can a-amylases cut at?
a-1,4 sites, not at a-1,6 sites
What is the function of lingual lipase?
initial digestion of triglycerides
What is the optimum pH of lingual lipase?
pH 4
What are lingual lipases denatured by?
Pancreatic proteases
What enzyme does lingual lipase work together with?
gastric lipase
When lingual lipase cleaves the outer fatty acids off triglycerides, what does it leave?
diacyl glycerol
What are the three types of papillae?
Foliate, circumvallate, fungiform
What are the two taste sensors (specialized epithelial cells) called?
Ion channel-based sensor
GPCR-based sensor
Whilst taste sensors are specialized epithelial cells, what kind of cells are odour (olfactory) receptors?
nerve cells
What happens in the pharyngeal phase of swallowing?
nasopharynx closes
pharynx wall contracts
contraction of the glottis
What are the dimensions of the average oesophagus?
25cm long and 2cm wide
What type of cells line the oesophagus?
stratified squamous epithelial cells
Control of GI motility and secretion is mediated by which parasympathetic nerve?
Vagus nerve (CN X)
Vagus also carries afferent fibres which contribute – feedback system.
Salivary secretion is mediated by which parasympathetic nerves?
Facial and glossopharyngeal nerves (CN VII and IX)
Chewing involves mandibular
- Elevation and ________
- Protraction and ________
- Medial and _______ movement
Chewing involves mandibular
Elevation and depression
Protraction and retraction
Medial and lateral movement
