OB S2- Control of salivary secretion Lecture 4 Flashcards
What is the neural control of salivary secretion?
- Efferent nerves (secretomotor)
- Parasympathetic nerves (ACh release)
- Sympathetic nerves (NA)
what do peptidergic nerves affect?
acinar, ductal & myoepithelial cells
Name 3 possible neuropeptide transmitters.
- Substance P
- Vasoactive intestinal peptide (VIP)
- Calcitonin gene related peptide (CGRP)
What does myoepithelial cells receive?
Receive innervation from parasympathetic and sympathetic neurones
What nuclei does the initating signal go to before parasympathetic nerves?
brainstem salivary nuclei
Where does the initating signal go to before sympathetic nerves?
thoracic spinal cord
What is a reflex?
innate, automatic, predictable, goal-directed response involving the CNS, to a known stimulus
What is an adequate stimuli for salivary reflex?
usually associated with feeding
what type of innervation does reflex control of salivary secretion have?
Complex secretomotor and vasomotor innervation
what is salivary secretion dependant on?
reflex activity
what is the stimuli for gustatory-salivary reflex delivered to?
gustatory receptors in Taste Buds
what is the order of magnitude of secretion for different tastes?
SOUR > SALT > BITTER & SWEET
when in maximal flow achieved?
5% Citric Acid (up to 7 ml per min)
What do mechanoreceptive afferent neurones innervate?
- Periodontal ligament
* Oral mucosa •Temporomandibular joint •Muscle
What is used to collect salvia?
Lashley cup and cannula
On which side is the greater flow of salvia?
chewing side
How long does salvia secretion continue?
as long as the stimulus is there
What reflex does not exist in humans?
olfactory-parotid salivary reflex
What reflex does exist in humans?
olfactory-submandibular salivary reflex
what is the difference between salvia produced from the parotid and the submandibular?
the salvia produced from the parotid glqnd is more for the fucntion if chewing whereas slavia from submandibular gland is to prepare mouth for food
What do higher centres do for initiating the signal for salivation?
- facilitate
- also inhibit (not at will) – i.e. dry mouth with anxiety
- but cannot enhance response
What is the conditioned stimuli -role of higher centres?
An association of the stimulus with actual food intake rather than the direct oral stimulus of food intake
what is the sensation of mouthwatering due to?
sudden awareness of saliva already present in the mouth
how is the preformed salvia secreted?
Contraction of either salivary myoepithelial cells or facial musculature of the floor of the mouth
what was the conditioned reflex demonstrated by?
Pavlov in the dog (and ourselves in the rabbit) in which a certain set of conditions normally accompany a natural stimulus
