Saliva II and III Flashcards
What are the details about the parotid gland?
- largest
- serous
- compound
-tubulo-alveolar
-Stenson’s Duct
-passes through
buccinator
-opens into
vestibule - opposite 2nd
upper molar
Doesn’t add a ton to the lubrication of the oral cavity.
Parotid duct aka stenson’s duct.
At rest only about 20% of saliva but when stimulate about 50% of saliva. Because it’s the biggest,
What are the details abut the submandibular gland and sublingual gland?
Submandibular: - mixed compound alveolar or tubulo-alveolar Wharton’s Duct
Sublingual: mucous compound alveolar or tubulo-alveolar numerous ducts
What are some minor salivary glands and what percent composition of the saliva do these produce?
labial buccal palatine glossopharyngeal lingual (glands of Von Ebner)
together make less than 10% final salivary composition
Wat is the salivary gland unit composed of?
Acinus, Intercalated duct, granular duct, striated duct, excretory duct.
What determines the amount of proteins, and ions that are secreted? What does this have to do with morning and night?
Flow rates determine the amounts of proteins, ions that are secreted
Total Volume per day = 750ml (to 1,500 ml…)
There is an underlying circadian rhythm that controls saliva flow
- greatest during the day
- lowest during the night
As well the concentrations of ions can vary at any particular flow rate
What controls the variables for gland dynamics?
What controls these variables? type of stimulation (Obj. #3) type of duct system the gland contains: intercalated ducts - cuboidal striated ducts - columnar excretory ducts - pseudostratified
We won’t need to know the shape of these ducts. But we may need to know how to draw a gland.
What type of transport occurs across duct systems of a gland?
Transport across duct systems of a gland:
intercalated ducts - ??? striated ducts - mainly active* excretory ducts - mainly passive
Sodium pumped out and bicarbonate pumped in (this is in and out of the striated ducts)
What is stage one of the duct system? Stage 2?
Stage 1: Acinus -primary saliva Plasma – like Content not dependent on flow rate - Active transport Sodium actively removed Bicarbonate in, chloride ion out of lumen of gland.
Stage 2: Duct
What have micro-puncture experiments shown about the duct system?
Micro-puncture experiments have shown that concentrations of ions vary along the duct system
What does sodium do with increase in flow rate?
it increases by a lot so if you weren’t taking it out there would be a lot of it in there. Chlorine and bicarbonate also increase with flow rate.
How is most salivary secretion in humans induced?
Most salivary secretion in humans is stimulation dependent. Stimuli include:
- mechanical - taste - muscular pressure on teeth - sight/ olfaction are less involved - reflexes - *nervous stimulation*
The salivary glands are controlled by the two types of autonomic stimulation which are? and what do they do?
The salivary glands are controlled by both types of autonomic stimulation
parasympathetic = volume sympathetic = protein production
Parasympathetic will increase the volume (rest and digest, like eating something)
What are the four main components of the duct system
There are four main components of the duct system:
Acinus: (1º saliva, isotonic)
2) Duct system proper
- modification of electrolytes in saliva
3) Blood vessels (dilate/ constrict)
4) Myoepithelial cells (contractile)
Isotonic is like plasma.
What should we know about nervous innervation?
This is the extent of what she wants us to know about the nervous innervation.
Parasympathetic comes from cranial nerves
Sympathetic comes from the spinal cord
For the parasympathetic innervation pathway of the parotid gland, what is the PreGanglionic? What is the postganglionic?
PreGanglionic - inf. Salivatory nucl.
- IXth Cranial nerve
Postganglionic - enters gland
For parasympathetic innervation pathway for submandibular/sublingual, what is the preganglionic and postganglionic?
PreGanglionic - sup . Salivatory nucl.
- VII th Cranial nerve
Postganglionic - enters gland
For the sympathetic innervation pathway for the parotid, wher e is the preganglionic and postganglionic?
PreGanglionic - Lateral Horn - spinal gray
- Superior Cervical Ganglion
Postganglionic - via major blood vessels
- enters gland
For the submandibular/sublingual where is the preganglionic and postganglionic located?
PreGanglionic - Lateral Horn - spinal gray
- Superior Cervical Ganglion - synapse
Postganglionic - via major arteries
- enters gland
In the acinar cell where are the neurotransmitters receptors located? and what occurs when this receptor is received?
Acinar cell. Neurotransmitters receptors are on basolateral side.
Start making proteins from the ATP cAMP cycle thing and secrete them as this is activated.
In the parotid acinar cell secretory events diagram, what occurs with the sympathetic and the parasympathetic?
The protein production occurs via the beta receptors and the salivary volume production mainly occurs via parasympathetic stimulation of the muscarinic receptors.
The same cell makes protein and transports water.
Point is that sympathetic and parasympatehtic systems for making protein and secreting water act on the same cell.
When you have things happening in the same cell, they all cross talk. So it’s hard to develop drugs to treat these things.
Remember the two receptors above. Muscarinic receptors. DAG PIP2 pathway for water.
How is salivary secretion primarily controlled?
Salivary secretion 1° controlled by autonomic neurotransmitters
Parasympathetic transmitters acting on acinus
- acetylcholine (ACh)
- Substance P (SubP)
- Vasoactive Intestinal Peptide (VIP)
Sympathetic
- norepinephrine (NE)
Saliva is formed by a 2 stage mechanism which is
Saliva is formed by a 2 stage mechanism:
- stage 1 at the level of the acinus
\_\_\_\_primary isotonic saliva\_\_\_\_\_
- stage 2 modified at the level of the duct
\_\_\_\_modification of electrolytes (hypertonic, compared to plasma)\_\_\_\_\_\_\_\_\_\_\_
To compound things there are two transduction mecanisms at the cellular leve, these are?
To compound things;
there are two transduction mechanisms at the cellular level
- Type 1 - b adrenergic and VIP activated
(increase in cAMP levels) - Type 2 - a adrenergic, Sub P and muscarinic/cholinergic activated
(increase in calcium ion levels)
You have one pathway regulated through cAMP (sympathethics), and the other pathway is through calcium levels.
Do both parasympathetic and sympathetic increase the salivary flow?
BOTH INCREASE THE SALIVARY FLOW BUT THE SYMPATHETIC IS SHORT LIVED.
It peters off after a bit while the parasympathetic continues to increase.
What factors then effect saliva?
1 - CNS Salivary Centres
- neuroses, emotions, tumours, drugs
2 - Autonomic Outflow Alterations
- encephalitis, accidents, drugs, surgery
3 - Gland problems - irradiation, excision, obstruction, infection, Xerostomia
4 - Alterations to Electrolyte balance
- dehydration, diabetes, uremia, odema, cardiac failure
If you’re stressed and nervous, eventually the sympathetic will decrease salivary flow.
