Unit 2 Flashcards
1
Q
SG’s are these types of glands:
A
exocrine, merocrine, compound (numerous acini)
2
Q
Parenchyma of the sg’s:
A
acini
3
Q
6 stages of SG development:
A
BEBLLD: bud, epi cord, branching, lobule, lumen, differentiation
4
Q
initiates sg formation:
A
thickening of oral epi
5
Q
What is the inital bud surrounded by after evagination?
A
condensed mesenchyme that has an endo plexus (6-8wks)
6
Q
Shape of oral epi cells that form initial bud:
A
hexagonal
7
Q
TF? Growth of initial bud stops with development of the epi cord.
A
F. continued growth of epi cord
8
Q
When does the epi of the epi cord become innervated?
A
onset of development
9
Q
These form the PSG:
A
neural crest-derived neurons, come together at primary duct
10
Q
Branching is successive rounds of:
A
end bud clefitng, epi proliferation, secondary duct formation
11
Q
Signals involved in branching:
A
fibronectin (from mesenchyme), FGF-10, signals from PSG
12
Q
Lobules are formed from:
A
CT
13
Q
functional unit of salivary gland:
A
acinus
14
Q
Responsible for formation of duct lumen:
A
VIP
15
Q
Source of VIP
A
PSG
16
Q
Stages of lumenal development:
A
Proliferation, Condensation, polarization, lumen formation, lumen expasion
17
Q
drives expansion of the lumen:
A
fluid movement through vessel
18
Q
Cell lining lumen:
A
K19+ luminal cell
19
Q
of cell types that make up terminal bulb
A
- MAD: myoepi, acinar, and ductal
20
Q
Structures derived from terminal buds:
A
intercalated duct, myoepi cells, acinar cells
21
Q
These become acinar cells:
A
proacinar cells
22
Q
Protein involved in epi-mesenchyme reactions:
A
integrin
23
Q
Steps in gland/ innervation development:
A
Initiation, gangliogenesis, innervation of branching epi, lumenization
24
Q
Involved in the proliferation of initial bud and duct cells:
A
FGF-10
25
involved in acinus/ branching morphogenesis
epi-mes interactions (I SEcrete: intercalated, striated, excretory)
26
Mucus cells are filled w:
mucus granules
27
Serous cells distal or proximal to mucous acini?
distal
28
Closer to the intercalated ducts, serous or mucous cells?
mucous
29
Serous cells are connected to lumen via:
secretory (intercellular) canaliculi, bw mucous cells
30
Location of myoepi cells:
bw basolamina and acinar or duct cells (extend to intercalated ducts)
31
Tissue origin of myoepi cells:
ectoderm, oral epi
32
How to id intercalated duct cells:
low cuboidal, central nucleus, few organelles ,secretory granules
33
How to id striated duct cells:
columnar, central nucleus, basal striations-mito in parallel, small secretory grnaules
34
Assoc w small secretory granules of striated duct cells:
EGF, fibronectin, kallikrein
35
Lumen of striated duct cells, permeable to water?
no
36
Function of mito in striated duct cells:
active transport/ reabsorption of Na+
37
Na+ enters here after reabsorption in striated duct cells:
duct cells and CT
38
How to id prximal excretroy duct:
simple or pseudostratified epi, basal cells bw columnar, some w lipofuscin granules, amorphous saliva in center
39
How to id distal segment of excretory duct:
stratified columnar epi, goblet cells, amorphous saliva in center
40
Relative contributions of major Sg's:
SM: 60%, P: 25%, SL:7%, minor: 7%
41
SMg opens here:
either side of frenulum of tongue
42
SLg opens here:
near SMg opening, ducts of Rivinus
43
Striated ducts of the major SG's:
P and SM: prominent, SL: Short
44
Intercalated ducts of the major Sg's:
P: Long, SM: shorter, SL: absent
45
Relative mucus/ serous contribution of SMg:
more serous than mucus
46
Minor sg's are not found here:
gingiva, vent tongue, central hard palate (sg tumors will not be found in these spots)
47
Location of minor sg's:
SUBmucosa, loose CT
48
TF? All minor sg's are mucus.
F. all except von Ebner's (pos tongue)
49
Ducts of minor sg's:
short
50
% contribution of minor sg's to total mucus secretions:
70%
51
TF? Minor sg's play a role in mucosal immunity.
T
52
Sg's that are only serous:
von Ebner and P
53
intercellular juncitons of acinar cells:
Tight junc, adherens junc, and desmosomes
54
Proteins assoc with tight junctions:
occludins, claudins
55
Proteins assoc with adherens junctions:
E-cadherin, catenin, p120, connected with actin
56
Proteins assoc with desmosomes:
desmoglein, desmoplakin, plakoglobin, connected with keratin
57
Which region of the intercellular junction is the the apical portion found in?
lateral (NOT baso-lateral!)
58
Fxns of tight jun, adh jun, and desmosomes:
permeability barrier, cell shape, stability
59
p120 knockout mice get:
duct cell tumors
60
3 factors in sg secretion:
gustatory stimulation, chewing, neuronal control
61
Para to SM/SL glands:
sup s. nuc. (brainstem), glossopalatine nerve, geniculate gang, chorda tympani n. (CNVII), lingual n., subm gang, glands
62
Para to P gland:
inf sal nuc (brainstem), CNIX, jugular gang, tympanic n., otic gang, p gland
63
Sym to glands:
T1 and T2 (thoracolumbar region), sup cervical gang, (middle meningeal a. to otic gang, to P) OR (maxilary a. to subm gang, to glands)
64
2 groups of nerve endings to acinar cells:
bw acinar cells and next to BL, all unmy
65
dictates the type of saliva produced:
neurotransmitter
66
Receps for sym and para nerves:
S: a/beta adrenergic. P: cholinergic
67
NT that leads to protein rich secretions, nt that leads to watery saliva:
NE, AcH
68
signal to help maintain branching:
neuturin, given after radiation
69
Leads to reduced expression of neuturin, and results of the reduced expression:
Apoptosis because of diminished para fxn, reduced neuturin leads to increases neuronal apoptosis
70
Tx with neutrurin:
red neuronal apoptosis, restores para fxn, inc epi regeneration
71
Leads to red para innervation:
HaN radiaiton
72
Gross comp of saliva:
99% water, 0.5% inorganic, 0.5% organic (crevicular fluid, bacteria, food, cellular debris, epi cells, pmns)
73
Crevicular fluid is:
serum exudate
74
of oral bac:
100 million (10^8)
75
Watery to viscous of the sg's:
P, SM, then SL
76
pH of saliva:
6.7 (5.6 - 8.0) 5.5 is the critical point for caries formation
77
of swallows per day and amt of bac swallowed each day'
2,500, 1-2.5g
78
__ml swallowed with each swallow:
0.3ml
79
Minor sg's:
labial, palatal, lingual (von Ebners), buccal
80
Resting contribution to total saliva:
SM/SL: 70%, P: 20%, Minor: 10%
81
Stimulated contribution to total saliva:
SM: 35%, P: 50%, SL: 7%, SM: 7%
82
Influence salivary flow:
body position, chemical stimulation, irritation of esophagus/ stomach
83
Gallons of saliva produced in a lifetime:
10,000
84
kg of protein produced in a lifetime:
190kg
85
Digestive function of saliva in regards to commensal microbes:
colonization, adhesion, nutrient
86
Proteective function of saliva in regards to pathogens:
Clearance, agglutination, Killing
87
Fxns of saliva:
water balance, excretion, antimicrobial, remineralization, form enamel pellicle, produce biological active substance
88
subtratum for bacterial adhesion
enamel pellicle (proteins adsorption to tooth surface)
89
Inorganic components of saliva:
CaPO4, KCl, NaHCO3, F, SCN, MgSO4, I, CO2, N2, O
90
Increased conc's of Ca and PO4 can lead to:
mineralized plaque/ tartar
91
Low mol w8 organic components:
urea, uric acid, free amino acids, lipids, creatinin, ammonia, glucose, cAMP, corticosteroids
92
Intrinsic proteins:
derived from acinar cells
93
List intrinisic proteins:
Sal amylase, Acidic PRP, Basic PRP, proline-rich glycoprotin, cistatin, histatin, mucins, peptides, statherin
94
Fxn in remineralization:
Cistatin, histamine, statherin,
95
Gs that release acidic PRP's:
P and SM
96
Highest to lowest composition of intrinsic proteins:
amylase, PRP, prloline-rich glycoprotein, statherin/cistatin, mucins
97
Extrinsic proteins in saliva:
sIgA, Lysozyme, lactoperoxidase, lactoferrin, cytokines, albumin, IgG, IgM, lipoproteins, serumproteins, and enzymes
98
how does sIgA enter the sg's?
via lymphocytes in surroundings in acini, taken into acinar cell
99
indicator of contribution of serum exudate to whole mouth saliva:
serum albumin
100
Fxns of mucins:
digestion, lubrication, tissue coating, anti-viral/ bacterial
101
Fxns of histatins:
anti-fungal/ bacterial, buffering, mineralization
102
Fxns of cystatins:
anti-viral, mineralization, tissue coating
103
Fxn of statherin:
tissue coating, lubrication, mineralization
104
Fxns of PRP:
mineralization, tissue coating
105
Fxn of amylases:
digestion, tissue coating, antibacterial
106
Antibacterial fxns:
CHAMP: cystatin, histatins, amylases, mucins, peroxidases
107
Anti-viral fxn:
Cystatins, mucins
108
Anti-fungal:
histatin
109
Tissue coating:
CAMPS: cystatins, amylases, mucins, PRP, statherins
110
Fxn in lubrincation:
mucins, statherin
111
Fxn in mineralization:
CHPS: cystatins, histatins, PRP, statherins
112
Fxn in digestion:
amylases, mucins
113
Fxn in buffering:
carbonic anhydrase, histatins
114
Most abundant protein in saliva:
amylase
115
Amylase breaks:
alpha 1-4 lycosidic bonds
116
pH range of amylase:
3.8-9.2 (stomach 3.5)
117
TF? Salivary amylase in functional in the stomach.
F
118
How do isoenzymes of salivary amylase differ?
glycosylation
119
MG1 is aka:
muc5b
120
Mucins:
high mol. w8, high CHO (carb side chains/glycans), sulfate groups, hard and soft tissue, enamel pellicle, bacterial adhesion (colonization), bacterial aggregation (clearance), blood group antigens (secretors), lubricant
121
Structure of MG1:
over 1000kD, multiple subunits, about 85% CHO, complex oligosaccharides (ABH, Lea, Leb blood group antigens)
122
Structure of MG2:
200-250 kD, single apomucin, about 70% CHO, O-glycosidic linkages
123
This mucin is evolutionarily younger:
MG2, only in mammalian lineage
124
Responsible for mucous lubrication:
negative charge on glycans
125
Salivary agglutination is aka:
gp-340
126
gp-340:
in pellicle, adhesion and aggregation of S. mutans, same as lung glycoprotein, spliced from DMBT1, TSG, member of scavenger receptor cysteine-rich superfamily (SRCS), 45% carb - 6% sialic acid (a2,3 linked), 12 fucose (a1,2 linked), innate response, made by sgs
127
Blood group and Lewis-antigens depend on:
secretor status
128
Basic PRP'sL
bind membranes, protect against tannins
129
Acidic PRP's:
Ca2+ binding proteins, , remineralization, bacterial adhesion counter receptors
130
Proline-rich glycoprotein:
adsorbs to tooth, lubrication, bacterial adhesion counter-receptor
131
Fxn of Statherin:
stabilize CaPO4 in solution
132
2 bacterial adhesion counter-receptors:
Acidic-PRP's, proline-rich glycoproteins
133
PRP's and statherin, high or low m.w.?
low
134
carrier proteins of Ca2+ in oral cavity:
acidic PRP's
135
Protein to fight C. albicans:
Histatic
136
Histatin 1, 3, 5:
38, 32, 24
137
TF? sIgA is bacteriacidal.
F.
138
Salivary proteins involved in acquired immunity:
sIgA, IgG
139
Salivary proteins in innate immunity and host defense:
agglutinating factors, antimicrobial proteins, and cationic antimicrobial peptides
140
List agglutinating facotrs:
sIgA, mucins, and salivary agglutinins
141
List antimicrobila proteins:
cystatins, von Eb gland proteins, P secretory gland proteins (PSP, SPLUNC2), Prolactin induced protein (PIP), secretory leukocyte peptidase inhibitor (SLIP), lysozyme, lactoferrin, lactoperoxidase
142
List cationic antimicrobial peptides:
histatins 1,3,5, a/beta defensins, cathelicidin, LL-37
143
mucin w more promiscuous bacteria binding:
MUC7
144
Source of lysozyme, lactoferrin, lactoperoxidase:
inflammatory cells
145
sIgA:
heavy/light/J chains, secretory component (heaviest), first line defense in all mucosal tissues, agglutination of microorganisms, netralize viruses, toxins, enzymes, opsoniztion and mediation of bactericidal activity, interactes with mucin, renders bacteria "mucophilic",
146
Secretory component of sIgA is composed of:
N- and O-linked oligosaccharides (carries all Lewis, siallyl La-epitopes)
147
Fxn of heavy chain of sIgA:
binding site ofr certain bacteria (E. coli, Actinomyces naeslundii, Strep. gordonii)
148
Lysozyme is derived from:
mainly from granulocytes and monocytes, but also sg's
149
Fxn of lysozyme:
hydrolysis of peptidoglycans in cell wall of gram + bacteria (lysis, cidal)
150
indicator of ongoing inflammation, could be periodontitis or cancer:
lactoferrin
151
lactoferrin is derived from:
granulocytes
152
Lactorferrin:
transferrin family, iron-binding glycoprotien, made by epi cells of sg ducts, in colostrum, milk, tears, bacteriostatic through sequestration of iron, bactericidal through membrane disturbances, host modulation, assoc w pd and caries
153
Is lactoferrin bacteriostatic or cidal?
can be either
154
lactoferrin is bactericidal through:
membrane disturbances
155
lactoferrin is bacteriostatic through:
sequestration of iron
156
Lactoperoxidase is derived from:
sg's (salivary peroxidase) and granulocytes (myeloperoxidase, 30-75%)
157
Lactoperoxidase-thiocynate-H2O2 system is involved in:
forms hypothiocynate (OSCN-) oxidation of bacterial enzymes (static or cidal)
158
Where does the thiocynate come from?
saliva
159
Where does the H2O2 come from?
non-cariogenic bacteria
160
How do cationic antimicrobial peptides kill?
inserting into membrane (facilitated by charge), modulates host cell response, directly attack internal targets
161
Disadv to using saliva as a diagnostic tool:
lower amt than in blood, conc's changes, components can be modified
162
miniaturized test devices;
micro-arrays, sensors, fluidics, nantoechnology "lab on a chip"
163
What we can measure in saliva:
elctrolytes (Ca, K), Ab's (HIV, Hep A-C), Cytokines, hormones (androgen, cortisol, stradiol, grogesterone, testosterone), Nucleic acids (DNA, RNA, human, mito, microbial, viral), drugs metabolites toxins (alcohol, cotini, phenytoin)
164
Uses of saliva in emergencies:
self diagnosis, on site monitoring, epidemics, bioterrorism
165
Pd inflammatory mediators in saliva:
IL-1B, IL-6, TNF-a, PGE2
166
Collagen and bone resorption markers in PD:
MM8 (collagenase 2), osteoprotegrin (OPG)
167
of proteins in salivary proteome:
over 2,000
168
2 forms of SS:
primary (sicca syndrome) and secondary (w other AId's, lupus, RA)
169
Form of SS that is systemic:
primary
170
Prevalence of SS:
0.2%-0.7% of pop
171
Oral mani of SS:
secondary to dry mouth: cervical caries, dry, leathery mucosa
172
Salivary d. mani:
swollen sg, parotitis secondary to xerostomia (children)
173
TF? All SS pts lose salivary flow.
F
174
Pts w SS may have:
blood dyscrasias/ lymphomas, cutaneous vasculitis, lymphadenopathy, primary biliary cirrhosis
175
most serious sequela of SS:
lymphoma
176
Dx criteria for SS:
2 of 3: dry eyes (ocular staining score), sg inflammation (minor sg biopsy), + serum Ab's
177
AutoAb's of SS are produced by:
B cells
178
Presence of autoAb's tells us:
patient has disease, levels dont tell us how active the d. is
179
Focus score greater than or equal to __ is indicative of SS:
50 lymphocytes / 4 mm2
180
TF? Inflammation is main determining factor in whether a pt will experience dry mouth.
F
181
other factors besides inflammation that may cause dryness:
apoptosis of epi cells, autoAb's that inhibit M3R activation
182
Factors contributing to SS:
gender, env (viral), genes, innate immune dysfunction, B and T cell abnormalities (adaptive)
183
Why does it affect women more?
many immune genes are expressed on X chomosome, mouse wo estrogen shows sg inflammation and increased apoptosis of salivary epi
184
Viruses induce secretion of:
Type 1 IFN (elevated in SS salivary tissue), IFN gene dysregulation (inducible gene, labial sg and peripheral blood)
185
Viruses that may play a role in SS:
CMV, EBV, HHV6, Human T lymphotropi virus 1, Hep C and D, Enterovirus
186
SS involves both innate and acquired immunity.
T
187
These produce high levels of type i IFN following viral activation:
dendritic cells in SS salivary tissues express TLR-7 and 9
188
Major producer of inflammatory mediators in SS:
macs (inc levels)
189
secrete inflammatory cytokines and express factors that activate adaptive immune cells in SS pts:
Salivary gland epi cells (SGEC)
190
Cell type(s) found in Sg biopsy:
B and T (% B increases with progression of disease)
191
TF? Both innate and adaptive immunity serve to promote chronic inflammation.
T
192
T cells produce:
inflammatory mediators, which are elevated in SS salivary tisue
193
Types of T cells in SS tisseu:
Th1, Th2, Th17
194
B cell abnormalitites in SS:
inc levels of cytokine BAFF (blood and saliva), many different autoAb's, abnormalities in expression of chemokine receptors that direct B cell migration, high risk of B cell lymphoma
195
Fxn of BAFF:
B cells that should die kept alive, secreting their Ab's, may explain being more prone to lymphoma, may become malignant
196
Biologics (biological products):
blood and blood components, gene therapy, tissues, and recombinant therapeutic proteins, may reduce inflammation in SS, diminish cell activation and/or reduce B cell numbers
197
Unstimulated and stimulated salivary flow:
0.3-0.4ml/min, 1.5-2.0 ml/min (5 times unstimulated)
198
Easy way to remember relative contributions of the glands:
60% subman for unstim and 35% subman or stimulated. 7% for minors always, the rest is parotid
199
Objective criteria for xerostomia/ hypofunction:
un: less than or equal to 0.1ml/min, stim: less than or equal to 0.7ml/min
200
Pts will have discomfort/ decay at this salivary flow rate:
0.2 ml/min
201
Causes of xerostomia:
salivary gland aplasia, water/metabolite loss, iatrogenic (meds, chemo, radiation)
202
Local factors that cause xerostomia:
decreased chewing, smoking, mouth breathing
203
Systemic diseases assoc with xerostomia:
SS, DM, DI, Sarcoidosis, HIV, HepC, graft vs. host, psychogenic disorders
204
Prevalence of xerostomia:
about 30% of pop 65+
205
Mucosal signs of SS:
mucositis, desquamation/ sloughing, atrophic mucosa, allergic or contact and lichenoid lesions, candidiasis
206
Signs of SS on tongue:
loss of papillae, crenations/ scalloped borders, redness, atrophy, fissures, lobulation
207
Signs of SS on lips:
dryness, peeling, fissuring, angular chelitis
208
angular chelitis:
fungal infection in corners of mouth, patients who are overclosed, vertical collapse, constant pooling at the side of the mouth
209
Candidiasis:
pseudomembranous, red or white, can be scraped away, red underneath, related to hyposalivation, cream cheese consistency, irritated, bleeds at times
210
Classic locations of candidiasis:
tongue and soft palate
211
Candidiasis is especially freuqent with patients that use:
corticosteroid inhaler
212
Med induced xerostomia;
over 500, neural mechanimss, stop drug, regain function, most don't damage glands,
213
Drugs that lead to xerostomia:
anti- cholinergic, hypertensive (ACE inhibitors, angiotensin rec blockers, a/beta adrenergic blockers, diuretics, histamines, opioids, relaxants, antidepressants, antipsychotics
214
Tricyclic anti-depressants block:
histaminic, cholinergic, and adrenergic rec sites
215
Antihypertensives that lead to reduced protein in saliva
non-selective and beta 1-selective adrenoceptor antagonists
216
Appetite suppressants:
inhibit uptake of noradrenaline (NE) and serotonin
217
Pseudophedrine:
sympathometic drug, acts directly on alpha-adrenergic receptors
218
central inhibition of salviary output:
block signals from forebrain/ hypothalamus going toward the salivary nuclei with a-2-adrenoceptor agonists, serotonin transporters, and NE transporters
219
Peripheral inhibition:
anticholinergic muscarinic receptor blockers
220
Radiation is most frequently used for this cancer:
scc, malignant epithelial proliferation
221
Tissue that is particularly sensitive to radiation:
acinar tissue
222
Flow from these sg's decreases rapidly in 1st wk after radiation:
P and SM, 50-60%, barely measurable at 6-8wks, further decrease for up to 3y
223
Acute phase after radiation:
loss of glandular cells and acinar shrinkage
224
Cause of permanent loss of sg function:
loss of acinar cells, then fibrosis
225
More sensitive to radiation, serous or mucous?
serous (P and SM)
226
TF? Mucous glands typically recover 100% of function.
F. 50%
227
Neg effects of sialorrhea:
pooling, choking, perioral dermatitis (sores around mouth and chin), infected, tx: drugs or surgery
228
Causes of sialorrhea:
GERD, rabies, heavy metal poisoning, anti-psychotics (clozapine), cholinergic agents (AZ, M. gravis,)
229
Tx for sialorrhea
botox, surgical removal of part of gland, reposition duct opening
230
Diff dx if salivary flow is greater than or equal to 0.2m/min:
Taste disturbances, burning mouth syndrome
231
Diff dx if salivary flow is less than or equal to 0.1m/min:
MIX, radiation, SS, other AI d., neurologic and endocrine, infectious d., congenital exocrine gland deficiences
232
Palliative tx for xerostomia:
water, biotene, saliva substitutes, oralbalance, different Rx, sugarless candy
233
Required for wax to simulate salivary fxn:
neural reflex, requires residual acini
234
Salivary substitutes we can Rx:
pilocarpine (salagen), cevimeline HCl (Evoxac)
235
MOA and SE's of pilocarpine:
para agonist, sweating, diarrhea
236
MOA of and SE's of cevimeline:
AcH derivative (activates entire para system), nausea, vomiting, bloating (last only 30m)
237
Most important tx for xerostomia:
fluoride: varnish, gel-kam (0.4% Stannous F), prevident (1.1% NaF Rx only), rinses wo alcohol
238
Brought into the lumen through striated ducts:
K+
239
AcH pw in acinar cells:
AcH, M3R, Gq, PLC, PIP2, DAG and IP3, Ca2+ release from ER
240
NE pw in acinar cells:
NE, B-adrenergic, Gs, AC, cAMP
241
Salivary secretion is driven by:
electrochemical stimulation
242
Exchangers involved in AcH mediated secretions:
Na/H (Nhe1) and Cl/HCO3 (Slc9a1?)
243
Cl- channel into lumen:
Tmem16A
244
K+ channel taking K out of BL mem:
Ik1 or Sk4 and Maxi-K or Slo (Kcnn4 Kcnma1)
245
Na/K/Cl cotransporter:
NKcc1 (slc12a2)
246
basolateral side:
Regulation of ion balance
247
apical side:
Water channel
248
Tight junctions in acini:
leaky, allow passage of water and sodium
249
Drives the flow of Na and water along gradient, creating energy:
Cl-, Na bw cells, water bw and through
250
Ca activates:
Chloride, K, and Na/K/Cl channels
251
Req for fluid and electrolyte secretion from acinar cells:
Ca release
252
Where are ions pumped in bicarbonate mediated secretions?
H+ BL, bicarbonate apical
253
bicarbonate mediated secretions, ligand dep or indep?
Ligand independent bc we are not talking about a nt
| Na/K pump and Na/H exchanger involved.
254
Rec for protein rich secretions:
beta adrenergic
255
active ___ leads to protein secretion in the symp pw to protein secretion
PKA
256
2 types of protein secretion:
exocytosis and vesicular transport
257
Required for packaging high conc of proteins into granules:
Ca2+ to shield high density of neg charges (esp. mucins: lare, highly glycosylated, neg charged proteins)
258
Vesical transport:
no loss of storage granules, occurs in absence of fluid secretion, can lead to build up of secretory proteinsin duct system, protein composition differs bw granules and vesicles (selective sequestration)
259
Para receptors:
M3, M1, alpha-2 adrenergic, Substance P
260
Sym receptors:
B2 adreneric or VIP
261
Na is removed principally by:
striated duct cells, into glnadular interstitium
262
Degree of hypotonicity is dependent upon:
salivary flow rate, stim = higher flow = higher salt conc
263
Removal of NaCl by ductal cells is dependent on:
transmembrane gradient for Na by the Na/K ATPase (pump) located in BLl membrane
264
How are Na ions absorbed by ductal cells?
from ductal lumen through a Na channel in apical membrane, also remove Cl from saliva in ductal lumen, Cl moves across ductal cell and into interstitium
265
Ion movements in striated duct:
Na and H out, K and bicarbonate in
266
What is required for taste recognition?
concentrations that reach their taste recognition threshold
