Reading; 9/26 Flashcards
1
Q
functional part of mammalian glands develop from:
A
epi interacting with underlying mesenchyme
2
Q
Define proximate tissue interaction
A
presence of mesenchyme in close proximity to epi is required for normal development of the epi
3
Q
proximate tissue interaction is aka:
A
secondary induction
4
Q
epi-mes interactions regulate:
A
initiation, growth, cytodifferentiation
5
Q
Mes is req for development of what part of the adult gland?
A
supporting part
6
Q
Composition of mes:
A
pluripotent CT stem cells and ECM
7
Q
Ex’s of undifferentiated pluripotent CT cells:
A
? fibroblasts, mast cells and macs
8
Q
Composition of ecm:
A
GAG’s and proteloglycans
9
Q
Functions of proteogycans in ecm:
A
give gel-like characteristic (form the hydrated ground substance), filtration, bind signalling molecules (ie Gf’s) in close proximity to their target cells
10
Q
Ex’s of GAG’s:
A
chondroitan sulfate, keratan sulfate
11
Q
How are proteoglycan subunits formed?
A
GAg’s are bound to a core protein
12
Q
How is the bristle brush-like structure in the ecm formed?
A
proteoglycan subunits (core protein bound gags) noncovalently bound to hyaluronic acid (a GAG)
13
Q
Where do proteoglycans function in filtration:
A
renal glomerular bm
14
Q
This makes up the fibrous component that gives the tensile strength to the ecm:
A
collagens
15
Q
These give adhesive support to the ecm:
A
2 glycoproteins: laminin and fibronectin
16
Q
Where are the 2 glycoproteins that give adhesive support to the ecm found?
A
laminin: basal lamina under epi, fibronectin: surrounding ecm
17
Q
This is a supramoleculare mat underlying the epi:
A
basal lamina
18
Q
Basal lamina is composed of:
A
Type 4 collagen, glycoprotieins (laminin, nidogen/ entactin) and proteoglycans
19
Q
laminin and entactin interact with __ and each other thru ___ :
A
integrins, receptors
20
Q
Integrins:
A
family of tansmembrane linker proteins
21
Q
Function of integrins:
A
linkage and communincation bw cells and the ecm, function and development of organs
22
Q
One of the most important fibronectin receptors:
A
transmembrane glycoprotein, connections to both cytoskeleton and ecm allowing communication bw cytoskeleton (in) and fibronectin (out)
23
Q
Receptors that allow cell matrix interactions:
A
fibronectin and laminin receptors (glycoprotein receptors)
24
Q
These facilitate cell-cell communication
A
ICAMs, by linking ecm to cytoskeleton
25
Functions of linkage of cells via ICAMs:
changes in cell shape, motility, migration, prollferation, and differentiation (gland development)
26
This makes the basal lamina:
secreted by epi
27
Function of basal lamina:
support, filtration, migration, polarity and diffferentiation of epi cells
28
This makes the ecm:
ct cells
29
The ecm contains:
collagen types 1 and 3, glycoproteins (fibronectin, entascin) GAGs' (chondroitan sulfate)
30
These are assembled into proteoglycans:
GAGs
31
How do the components of the bl and the ecm differ?
types of glycoproteins and proteoglycans
32
the major process for formation of adult salivary gland:
morphogenesis
33
The ecm provides regulatory cues for:
cell prol, diff, and morphogenesis
34
When does the ecm help to regulate cell prol?
development/ enlargement, cell replacement throughout life
35
Fate of proliferating cells in the glands:
specialization or remain a dividing or stem cell population that continues to proliferate
36
Define morphogenesis:
developmental processes responsible for formation fo shape and form of organ
37
What other developmental processes does morphogenesis require?
proliferation and migration
38
Ex's of morphogenic processes:
proliferation, migration, morphogenesis, glandular branching differentiation
39
Morphogenic process responsible for development of adult architecture:
mophogenesis
40
Morphogenic process responsible for specificity of cell types:
difffernetiation
41
TF? Morphogenesis and differentiation are dependent processes.
F. independent but concurrent
42
Define parenchyma:
functional glandular tissue
43
epi outgrowth of the buccal epi that invades the underlying mes:
glandular bud
44
The ct stroma makes up:
the capsule and septa
45
How does the parenchyma develop?
as a glandular bud that invades underlying mes
46
What form from the mes?
ct stroma (capsule and septa) and bvs
47
Mes is derived from:
neural crest cells
48
TF? Mes is needed for normal diff of sal glands.
T
49
What provide signals that direct morphogenesis and differentiation of the glandular bud?
ecm components synthesized by mes ct cells
50
Parotid glands originate here:
near corners of stomodeum
51
Submandibular glands originate here:
floor of mouth
52
sublingula glands originate here:
lateral to subm primordia
53
Define primordium:
1st beginnings of an organ or part in developing embryp
54
This differentiates into the main excretory duct of the sg:
bud closest to stomodeum
55
most distal portions of the bud form:
secretory end piece or acini
56
Origin of epi buds of parotid and minor sg's
ectodermal
57
Origin of epi buds of subm and subl sg's
endodermal (sub glands are endo)
58
What permits intermingling of the stomodeal ectoderm and cranial foregut endoderm?
breakdown of buccopharengeal membrane in the 4th wk
59
buccopharengeal membrane is aka:
oropharyngeal mem
60
breakdown of buccopharengeal membrane occurs in this wk of development:
4th
61
Why are we not sure about the origin of all sg's?
breakdown of buccopharyngeal membrane and mingling of tissues in 4th wk of develoment
62
Parotid glands originate in this wk of development:
6th
63
Subm glands originate in this wk of development:
end of 6th or beg of 7th wk
64
Subl glands originate in this wk of development:
about 8th wk
65
All minor sg's form from:
epi
66
When do the minor sg's begin to develop?
12th prenatal wk
67
6 stages of sg development:
initial bud, endothelial cord, branching, lobule, lumen, differentition
68
TF? The epi induces the underlying mes to form the bud.
F. reverse, mes induces buccal epi (tissue thickens to bc epi bud)
69
How is the growing epi bud separated from the condensation of mes?
basal lamina secreted by the epi
70
TF? The epi bud forms the epi cord.
F. reverse, cord forms bud *
71
What is happening in the surrounding mes during the formation of the epi bud?
condensation and proliferation
72
Basal lamina is bw:
cord and mesenchyme
73
Basal lamina is made of:
GAG's, collagen, and glycoproteins
74
TF? Both the basal lamina and the mes influence morphogenesis and differentiation of the sg's throughout development
T
75
What is happening during branching?
differentiation of gland and ct around the branches
76
What branches into terminal bulbs?
epi cord
77
These are the presumptive acini:
terminal bulbs
78
What leads to extensive lobulation?
differentiation of ct around the branches (lobulalation occurs during branching)
79
What does the glandular capsule form from?
mes
80
What surrounds the entire glandular parenchyma?
glandular capsule
81
This hollows out to form the lumen:
epi cord
82
lumen formation happens when?
6mo in all 3 major sg's
83
Order of lumen formation:
proximal (oral, terminal), distal, and branch ducts, midportion of main duct, acini, secretory granules
84
What leads to lumen development?
tight junction formation in cells that was initially simpler intercellular space
85
This happens during lumen formation:
extensive branching and growth of ct setpa
86
Final morphologic stage of sg development:
cytodifferentiation of acini and intercalated ducts
87
Mitotic shift during cytodiffferentiation:
from entire epi cord to the terminal bulb portions
88
Where are the stem cells that undergo proliferation and diff into acinar cells, ductal cells, and myoepi cells?
bulb region (terminal bulb cells)
89
When do myoepi cells develop?
During cytodifferentiation of acinar cells
90
TF? Acinar development is the same for mucous and serous.
F.
91
How are the stages of acini formation classified?
morphology of secretory granules and organelles
92
TF? Cytodifferentiation patterns are the same for all the sg's.
F, differs for serous and mucous cells
93
Intercalated duct cells develop from:
terminal bulb cells
94
What continues to mature after cytodifferentiation?
stimulus-secretion coupling and innervation of gland
95
Terminal bulb cells differentiate to become:
MAD: myoepi, acinar, ductal cells
96
These cells function as stem cells during development, adulthood and following injury:
terminal bulb cells
97
Preprogrammed pattern of gene expression specific for each cell type:
intrinsic factors
98
Signals provided by cell-cell / cell-matrix interactions, cytokines, hormones, and gf's in the extracellular milieu:
extrinsic factors
99
What defines boundaries bw groups of cells during development?
extrinsic factors
100
3 categories of fruit fly genes:
maternal, segmentation, and homeotic
101
Maternal fruit fly genes:
expressed: oogenesis, act: oocyte maturation, define broad regions in egg, regulate segmentation genes
102
Segmentation genes in fruit fly:
determine # and/or polarity of segments, define smaller regions of embryo
103
homeotic genes of fruit fly function:
regulate development of discreet body parts
104
What determines pattern of gene and TF expression during formation of sg's in fruit fly?
regulatory cascade
105
Initial polarity in fruit fly is in this axis:
A-P, head to tail, establishes segmentation of embryo
106
What establishes D-V, back to abdomen gradient that translates into specific structures?
Further development within each A-P segment
107
What genes regulate the formation of the sg's in the fruit fly?
homeotic genes, has homeobox domain (60-AA's, DNA binding domain)
108
Homeotic gene in fruit fly that encodes a TF responsible for the location of sg's:
Scr (Sex combs reduced)
109
Where in the fruit fly is Src uniformily transcribed?
posterior head (where sg's will be)
110
Overexpression of Src leads to:
sg development at ectopic sites
111
No expression of Src leads to:
no sg's
112
What establish the limits of sg development?
protein products of other genes
113
How do protein products limit sg development?
inhibit expression of Src
114
What establishes teh D-V boundaries of sg formation in fruit fly?
genes homologous to BMP-4
115
What determines the correct patterning of vertebrate embryos?
appropriate Hox gene expression
116
Responsible for the differentiation of cells along the A-P axis of all metozoans:
hox gene expression and restriction (fruit fly is a metazoan)
117
Where, in vertebrates, does Hox gene expression occur?
nervous system and its derivatives, inc neural crest cells
118
Cells instrumental in formation of sg's, teeth and overall craniofacial morpholoy throughout formation and differentiation of branchial arches:
neural crest cells
119
Scr gene is homologous to:
one of the Hox genes
120
Mammalian Hox genes regulate:
branching organs (sgs's, lungs), cell-cell and cell-matrix communications, cell fate, cell diff
121
Function of BMP-4:
regulate downstream events in differentiating teeth and maybe sg's, limit Scr expression, involved in cascade of gene expression that regulates epi-mes interactions (?) involved in branching and other morphogenetic events
122
TF? Teeth and sg's develop via reciprocal interactions bw epi and mes.
T
123
Primary morphogenetic process in sg development:
branching
124
What initiates branching that is followed by epi proliferation?
Cleft formation
125
Type of collagen that accumulates at branching point:
Type 3, critical for branching to occur
126
Collagen important for maintenance and support of branches:
Type 1 and 4
127
Type __ collagen leads to stabilization
1 and 4
128
Type __ collagen is involved in active branching
3
129
Mes is made of Type _ collagen and the BL is made of Type _
1 and 3, 4
130
GAG's are removed from this surface during cleft formation:
basal surface of epi
131
This causes disruption of the basal lamina during cleft formation:
removal of GAG's from the BL
132
biosynthesis and deposition of this is needed for branching:
proteoglycan
133
TF? Growth of rudiments are required for branching.
F
134
Predominant GAG's in bl of actively branching young rudiments:
Chondroitin sulfates, increases during stabilization
135
This GAG increases during stabilization:
Chondroitin sulfates
136
TF? epi expansion and branching are dependent upon one and other.
F. Independent processes, tunicamycin
137
Function of tunicamycin:
inhibits N-linked glycosylation, dec protein and cell proliferation (smaller rudiment w miniature lobes), normal branching and lobule formation
138
Localization of mitotic activity in the bud:
most peripheral regions
139
Function of hyaluronidase:
No cleft formation, disrupts BL interfering w signal required for
140
Destabilization of this inhibits cleft development and affects cell prol:
BL
141
What happens wo normal BL?
no branching or localization of proliferation/ mitotic activity
142
Functions of BL:
stabilization of epi, initiation and maintenance of lobular morphology
143
How might the Bl regulate morphogenetic changes?
directly or selective filtration or channeling of materials to epi (ions like Ca2+)
144
Affects that changing Ca2+ flow to epi might:
alter function of microtubules, migration, and arangement
145
What synthesizes collagen?
mesenchyme
146
This is required for stabilization after branching:
Type 1 and 4 collagen ( maintenance and support, adult gland) synthesis by mes
147
Function of collagenolyic activity:
selective breakdown of BL and communication bw epi, BL, and surrounding mes
148
Epi can be grown in vitro in this matrix:
Matrigel, artificial matrix
149
Matrigel is made of:
laminin, Type 4 collagen, heparan sulfate, entactin, and nidogen
150
Function of FGF in morphogenetic process:
Stalk elongation
151
Function of EGF in morphogenetic process:
regulation of branching
152
The combo of these added to Matrigel results in morphology similar to in vivo:
FGF and EGF
153
Regulates
| presentation and distribution of Gf's to epi in vivo:
ECM molecules
154
These regulate branching morphogenesis:
ECM and specific GF's (EGF, right?)
155
Initiation of cytodifferentiation of acinar cells is dependent upon:
preprogrammed development, early stages of morphogenesis
156
TF? Mesenchymal factors are required for secretory cell diffferentiation.
F. may be independent
157
What is req for cytodifferentiation?
epi-mes interactions in situ, then exocrine cell diff wo the continued presence of mes
158
What type of coupling is there bw gland morphogenesis and cytodifferentiation?
partial, independently controlled processes
159
When is full differentiation of functional secretory component apparent?
birth
160
When is functional secretory component complete?
onset of solid diet, masticatory stimuli
161
Acinar: mucous, serous, or mixed?
serous
162
tubular: mucous, serous, or mixed?
mucous
163
Tubuloacinar: mucous, serous, or mixed?
mixed
164
Postnatal development process:
maturation of stimulus-secretion coupling, making of neural connections from the ANS
165
What does stimulus-secretion coupling link?
secretagogue-mem receptor to signal transduction pws wiin the cell and controls acinar secretions
166
What is the primary regulator of sg function?
ANS
167
Glands w ducts:
exocrine
168
Sg's, exocrine or endocrine?
exo, but associated with substances that may be secreted by endo mechanism
169
Biologically active substances that sg's are associated w:
nerve GF, EGF (may be secreted via endocrine system)
170
Sg's are classified as what type of glands?
compound tubuloacinar glands, branched duct system and secretory units with both tubular and acinar portions
171
Method of secretion classificaiton of sg:
merocrine (partially secreting), repeatedly functional: vesicle fusion w apical mem, exocytosis, insertion of vesicular mem back into apical mem
172
Volume produced by major sg's per day:
0.5 to 0.75 L
173
location of major sg's:
apart from oral cavity with which they communicate
174
How many major salivary glands are there?
6, 3 pairs
175
Location of minor sg's:
oral cavity, bw hard/soft palate and tongue, behind teeth
176
Name the 5 minor sg's:
buccal, lingual, labial, palatine, glossopalatine
177
Minor sg named as eponym:
Glands of Von Ebner
178
mucous secretions produce:
mucins, lubricant for chewing, deglutition (swallowing) and digestion
179
serous secretions contain:
water, enzymes (amylase and maltase), salts, and organic ions
180
Secretion type of parotid:
purely serous adult, predominantly serous newborn
181
Secretion type of palatine glands:
purely mucous
182
Secretion type of subm and subl glands:
mixed, subm: mostly serous, subl: mostly mucous
183
Function of serous component of saliva:
chewing, debris removal, digestive potential debated
184
pH range of stomach after a meal:
6.7-7.5, allows activity of amylase, DNAase and other enzymes
185
3 ways salivary enzymes aid digestion:
break down to starch/ sucrose/lipid, facilitate access by increasing surface area, clearance of food stuck to teeth and oral mucosa
186
Size order of major glands:
Parotid, sugm, subl
187
Anatomical location of subm gland:
near the angle of mandible
188
Sg's w extensive capsules:
parotid and subm
189
Does the subl gland have a capsule?
yes, minimal
190
% contributions of the 3 major sg's:
Subm: 60%, Parotid: 25%, Subl: 5%
191
Striated duct length, longest to shortest for major sg's:
subm, parotid, subl (same order as % contribution)
192
Sym innervation (vasomotor) to all intercalated ducts:
postganglionics via superiro cervical ganglion
193
Preganglionic para innervation (secretomotor) to long and narrow intercalated ducts:
inf salivatory nuceus via CN 9
194
Preganglionic para innervation (secretomotor) to intercalated ducts that are shorter than in parotid or inconspicuous:
sup salivatory nucleus via chorda tympani (CN 7)
195
Postganglionic para innervation (secretomotor) to long and narrow intercalated ducts:
otic ganglion to auriculotemporal n. to gland
196
Postganglionic para innervation (secretomotor) to intercalated ducts that are shorter than in parotid or inconspicuous:
Subm ganglion to gland
197
Arterial supply to long and narrow intercalated ducts:
external carotid branches
198
Arterial supply to intercalated ducts that are shorter than in parotid:
facial and lingual branches
199
Arterial supply to intercalated ducts that are inconspicuous:
subl and submental
200
diseases characterized by masticatory pain:
glandular inflammatory diseases, ie mumps
201
Location of parotid gland:
ant to external acoustic meatus and mastoid process, inf to zygomatic arch, lateral and pos to the ramus on surface of masseter m.
202
Parotid gland is anatomically closely related to these structures:
facial n., external carotid, sup temporal and maxillary vv. and numerous cervical lymph nodes
203
Relation of parotid to facial n. begins at this wk:
10th wk
204
Duct from parotid:
Stenson's
205
Path of Stenson's duct:
lateral surface of parotid, cross anteriorly across masseter m. and buccal fat pad, sharp medial bend ant to masseter into papilla opposite Max2M
206
Epi of Stenson's duct becomes continuous with:
mucous membrane of mouth
207
Location of subm gland:
medial to and under partial cover of mandible, closely assoc w mylohyoid and medial pterygoid mm., subm lymph nodes and facial aa. and vv.
208
Subm duct:
Wharton's
209
Path of Wharton's duct:
extend anteriorily in floor of mouth, open at subl papilla at side of frenulum of tongue
210
Location of subl gland:
beneath mucous membrane of floor of mouth
211
How is the subl gland different than the other 2 major sg?
large collection of small glands vs. one discreet gland
212
Excretory duct of subl gland:
Bartholin's ducts
213
Path of Bartholin's duct:
join subm duct or open w a separate papilla
214
These, smaller sublingual ducts may join the subm duct or open separately into floor of mouth
Duct of Rivinus *
215
How many acinar cells make up each acini?
5-7
216
What surrounds and divides the sg into separate lobules?
Ct of the glandular capsule and septa
217
How are secretions squeezed out of acini?
myoepithelial cell contraction following neural stimulation
218
name the 3 types of secretory endpieces:
serous, mucous, and mixed
219
2 types of ducts:
intercalated and striated
220
Interlobular ducts:
excretory, bw lobules
221
Function of ct septa:
support and conduit for nerves (mostly autonomic), bvs and lymphatics
222
Pattern of blood supply to sg's:
larger vessels enter each lobe at one point and branch to supply each lobule, duct system drains in similar manner
223
TF? Duct system is the same for each major sg:
F
224
2 main structural parts of duct system:
intralobular and interlobular portions
225
2 types of intralobular ducts:
intercalated and striated (secretory)
226
Major sg with the fewest number of intralobular ducts and greatest number of interlobular
subl glands (both striated and intercalated ducts are very short)
227
Major sg with the largest number of intralobular ducts:
parotid, then subm, then subl (more ducts does not mean more excretion)
228
Major sg with the most endpieces:
subl glands
229
Intercalated ducts:
1st (most distal) part of intralobular system, low cuboidal epi, drain acini
230
Describe the cells of intercalated ducts:
few secretory granules, some RER, mito and round or oval centrally placed nuclei
231
2nd largest intralobular type:
striated ducts
232
Location of striated ducts:
bw intercalated and excretory ducts
233
striated ducts are aka:
secretory or salivary ducts
234
Most specialized sg ducts:
striated
235
Which sg ducts complete most ionic transport functions from acinar lumen to OC?
striated ducts
236
Describe the cells of striated ducts:
tall columnar epi, eosinophilic cytoplasm, spherical, centrally or eccentrically placed nuclie
237
What gives the striated appearance?
basal cytoplasm, striations perpendicular to base of cell, infoldings of basal plasma mem makes cytoplasmic rows w many mito
238
Ion movements in striated duct cells:
Na rebsorption, K excretion
239
Hormones that affect striated duct cells:
adrenal cortical steroid hormones, mainly aldosterone (similar histo and fxn to renal DT)
240
Affect of sodium reabsorption in striated duct cells:
isotonic to hypotonic saliva (excretory duct also involved)
241
Cell type surrounding the central lumen:
striated
242
Cell type of excretory ducts (interlobular):
primarily stratified columnar, some pseudostratified epi
243
Cell type changes as ducts get larger:
simple columnar, to pseudos or stratified, columnar epi, to SSE at entrance to OC, continuous w buccal epi
