GI physio Flashcards
what is the digestive function of saliva
taste
Lubricant
Initiate digestion of starch
initiates digestion of fat
where are the locations of the salivary glands
parotid: cheak
Submandibular salivary gland - back of mouth
sublingual salivary gland- font of mouth
what is the duct is associated with the parotid gland
stensen’s duct
where does the stensen’s duct open up
upper second molar
what kind of gland is the parotid gland
serous gland (watery)
what does the parotid gland produce to aid in digestion
amylase
what is the duct associated with the submandibular gland
wharton’s duct
where does wharton’s duct open
beneath the base of the tongue
what kind of gland is the submandibular gland
Serous and mucous
what does the submandibular gland secrete
water/electrolytes
mucin
when is the submandibular gland active
at rest
what is the duct associated with the sublingual gland
lesser sublingual (Rivinus’s) duct
where does the sublingual gland secrete
anterior floor
what does the sublingual gland secrete
mostly mucous
where are the minor glands int eh oral cavity
Labial Palatine Buccal Lingual Sublingual mucosae
what are the lingual salivary glands
Von Ebner gland
what do the minor salivary glands secrete
mostly mucous except von ebner
how much salivary contribution do the minor salivary glands add
5-10% total saliva
what cells tend to hang out in the minor salivary glands
lymphocytes
what are the rolls of Von ebner’s glands
Taste
Secrete lingual lipase
how do von ebner glands aid in aste
facilitates contact with taste buds
rinses duct of circumvallate and foliate papillae
what is the roll of lingual lipase
fatty acid digestion
does lingual lipase only work in the mouth
Continues into stomach (fundus)
why would the mouth secrete mucous
help with food bolus movement and respiration
what is an acinus made of
acinar cells (blind sac) Myoepithelial cells
what cells are included in acinar cells
Serous cells
Mucous cells
what do acinar serous cells secrete
enzymes
what do acinar mucous cells secrete
Mucin
what are the ducts of a salivon from the acinus
Intercalated duct
Striated duct
excretory duct
what is saliva made of
water (99.5%)
inorganic salts
organic compnents
what are the inorganic salts of the saliva
Sodium Potassium Chloride Bicarb calcium phosphate magnesium sulfate
what are the organic ompents of the saliva from acinar cell origin
amylase Lipase Mucoproteins Proline-rirch proteins Tyrosine-rich proteins (others)
what are the organic compnents of nonacinar cell origin
Lysozymes
Immunoglobulin
Growth factors
Regulatory peptires (NGF)
how is pH of the saliva controlled
highly buffered between 6.7 and 7.4
what is the primary mechanism for how saliva is secreted into the lumen
Cl- flows through the cell into the lumen
Na passes between the cell into the lumen
how does the body regulate movement of ions to get saliva to flow into the lumen
non lumen side: K pumped out of cell 2 k pumped in and 3 Na pumped out of cell na and K pumped in with addition of 2 Cl Lumen side: Cl pumped into lumen
what does water follow for the primary mech for saliva secretion
NaCl
what does the alternative mechanism for substational fluid secretion include
take into CO2 from the nonlumen side to make HCO3
HCO3 pumped out and CL- pumped into the cell
(also pumps out HCO3 to the lumen
what is the intracellular Na concentration of salivary cells
Kept low
what is the intracellular K concentration of salivary cells
kept high
what is the intracellular Cl concentration of salivary cells
High
what is the Ca in unstimulated salivary cells
Low
what does the low ca of unstimulated salivary cells do
K and Cl channels are closed
what does stimulation of salivary cells lead to
Ca opens Cl and K channels
how does Na get into the lumen salivary glands
Na leaks through tight junctions to follow Cl
how do ion concentrations change with flow rate
Na increases most
HCO3 increase middle
Cl increases slightly bellow
K stays the same concentration
where does primary secretion occur
Acini
where does Secondary modifacion occur
in the duct
where in the duct is H2O permiable
in the acini but not permiable in the duct
how does concentrations change in the ducts of the salivary glands
Na, Cl, HCO3 reabsorbed
K secreted
is H2O absorbed along the ducts
No
what is the flow rate along the salivary ducts
slow (allows for more reabsorption)
is electrolyte composition affected by flow rate in primary secretion
No
what is the composition of primary secretion
Plasma like (isotonic)
is electrolyte composition affected by flow rate in secondary secretion
yes, much so
how does the concentration of K and Na change in secondary secretion due to flow rate
high [K]: low flow rate
High [Na]: high flow rate
what is the tonicity of secondary secretion
Hypotonic
where does primary and secondary secretions occur
primary: acinar
Secondary; ductal
why does bicarb level off in concentration during an increase in flow saliva
to keep from getting too basic
what is the most abudnace protein in saliva
Mucin
what glands produce mucin
sublingual and submandibular glands
what is mucin rich in
Carbs
what is the roll of mucin
salivary viscosity
what galnds produce amylase
parotid gland
how is amylase packaged
Zymogen granules
what is the roll of amylase
breakdown of starch
what are the immun associated proteins of the saliva
Muramidase
Immunoglobulin
Lactoferrin
what is the action of muramidase
lyze muramic acid in the cell wall of many bacteria
what is the roll of lactoferrin
Binds iron
what are the Calcium binding proteins of saliva
PRP, TRP, cystatins, histatins
what is the roll of calcium binding proteins
promote mineralization of enamel
what is the roll of EGF in saliva
stimulates gastric growth
what is the roll of NGF in saliva
important for sympathetic nervous system
how does the sympathetic system affect the salivary glands
acts on the blood vessels
what does the parasympathetic gland ac on
Glands of palate and nose sublingual gland submandibular gland Parotid glands Lingual glands
what does CN VII (facial nerve) innervate
Glands of the palate and nose
Sublingual
Submandibular galnd
what does the glossopharygneal (CN IX) innervate
parotid glands
lingual glands
what parts of the glandular system does the ANS act on
Acinar cells
Ductal cells
Blood vessels (vaso dilation and constriction)
Myoepithelial cells (contractive properties)
what is the neurotransmitter for parasympathetic
Acetylcholine
what is the neurotransmitter for sympa
norepinephrine
what are the other neurotransmitters for salivation
Substance P and vasoactive intestinal peptide
Neuropeptide Y and calcitonin Gene relate peptide
what are the mechanoreceptors of the salivary reflex
periodontal ligaments
taste buds
where do afferent impulses of the salivary reflexes travel
Trigeminal
Facial
Glassopharyngeal
where do silvary reflexes synpase
trigeminal and solitary nucleus
what does parasympathetic stimulation do to salivary acinar cells
release Ach onto salivary acinar cells and results in a watery plasma like secretion via a secondary messenger pathway
what are the important internal signals for salivary secretion in response to parasympa
Ca released in the cell vauses K and Cl channels to open icnrease luminal Cl concentraion Intercellular sodium follows Water follows
what is the mehanisms of protein secretion intracellularily
Uses GTP with PKA
what receptors are activated for salivary secretion
Muscarinic or alpha-adrenergic receptor activation
what is the primary neurotransmitter for salivary secretion
Acetylcholine (some effect of norepinephrine via alpha adrenergic receptor)
binding of acetylcholine leads to
Opening of Ca sensitive Cl and K chennel
increase flow rate and decreased ductal modifiaction
what channels does aceylcholine act on
Muscarinic
Alpha-adrenergic
what knid of saliva does norepinephrine produce
Protein rich
what receptor does Noepinephrine act on
Beta-adrenergic receptor
what are the causes of Xerostomia
Aging
drugs (diueretics, antidepressats, antihistamines, antihypertensives, anti-cholinergic drugs)
radiation
Sjorgren’s sydrome
how does one manage xerostomia
stimulate muscarinic receptors (Pilocarpine - ach agonist)
treat symptoms
wheree is most water absorbed
into blood in small intestine followed by large intestine
what is the structure of GI tissue
Villus
Microvilli
what fills the villus of GI
Lacteal
Capillaries
