Quiz 4 Flashcards
1
Q
define oral mucosa
A
The moist mucous membrane lining
the oral cavity
2
Q
what are the functions of thr oral mucosa?
A
Propulsion of food (bolis)
* Initiation of digestion (in saliva)
* Sensation and Secretion (pain, temp, Propreosention)
* Protection
* Protects deeper tissues
* Immune function
* Tonsils
* Forms impermeable barrier (exception: floor of the mouth)
3
Q
what are the three thypes of oral mucosa?
A
- Masticatory mucosa (25%)( related to chewing)
- Lining mucosa (60%) most
- Specialized mucosa (taste buds 15%)
4
Q
what is parakeratinized epithelium?
A
similar to keratinized except that superficial cells have nuclei, cytoplasm does not stain as intensely with eosin
5
Q
describe masticatory mucosa
A
-Stratified squamous keratinized or parakeratinized epithelium
-Lamina propria ( loose CT)
-Location: Covers gingiva, hard palate (some sources include dorsal surface of the tongue)
6
Q
describe the lining mucosa
A
-Stratified squamous non-keratinized epithelium
-Covers inner surface of lips, cheeks, soft palate, inferior surface of the tongue, floor of the oral cavity
-Connective tissue layers have elastic fibers
-Permeability: Floor of the oralcavity is thinnest epithelium with permeable cells (under the tonge)
* Sublingual medications are rapidly absorbed
7
Q
describe the specialized mucosa
A
-Based on function of carrying taste sensation to the central nervous system
-Dorsal surface of the tongue (tastebuds are associated with lingual papillae and have a role in chemical sensation of taste)
8
Q
what is this pointing to?
A
taste buds
9
Q
what is this pointing to?
A
apical taste pore
10
Q
what is the skin and oral mucosa of the lip
A
Skin: thin keratinized epithelium with hair follicles
Oral mucosa: thick liningmucosa with minor salivary glands
11
Q
Mucocutaneous border (vermillion border)
A
-no glands, deep connective tissue papillae have blood vessels and nerves responsible for color and sensitivity
-the lack of glands is why lips may get dry
12
Q
what is the gingiva
A
the gums
13
Q
what are the two parts of the gingiva?
A
-The part facing the oral cavity (masticatory epithelium)
-the part facing the tooth
14
Q
the gingiva facing the tooth has two parts what are they
A
-inner basal lamina that binds calcified tissue
-external basal lamina that binds connective tissue
2 basement membranes
15
Q
what are the Four types of papilla
A
filiform
fungiform
circumvallate
foliate
16
Q
describe the filiform papillae
A
keratinized projections with mechanaical function (no taste buds)
17
Q
describe the fungiform papillae
A
mushroom-shaped with taste buds on the dorsal surface
18
Q
describe the circumvallate tastebuds
A
large, dome-shaped structures surrounded by a moat-like invagination with numerous taste buds
19
Q
descibe the folate papillae
A
greater number in younger individuals, many taste buds
20
Q
what is this pointing to
A
filiform papillae
21
Q
what are the lines pointing to
A
22
Q
what is the line and arrows pointing to?
A
taste buds on apical
23
Q
A
taste buds on lateral
24
Q
which papille has no taste buds
A
filiform
25
where are filiform papillae located
Anterior 2/3 of the tongue
26
where are fungiform papillae located
Tip and two sides of tongue
27
where are circumvallate papillae located
In a V-shaped row just anterior to the terminal sulcus
28
where are foliate papillae located?
Posterior lateral surface of the tongue
29
how many baby teeth and grown up teeth do we have
Normally 32 permanent teeth and 20 deciduous teeth- embedded in the alveolar processes of the maxilla and mandible
30
what are the hard tissues of the teeth
-Enamel
-Dentin
-Cementum
31
what is the crown?
part covered with enamel
32
label
33
describe enamel
-Acellular, avascular, nonvital/insensitive
tissue
-Derived from epithelium (ectoderm) of oral cavity
-Enamel is produced by ameloblasts become squamus (degenerate after enamel is fully formed)
34
desscibe dentin
-Avascular, sensitive tissue (capable of
repair)
-Forms bulk of tooth
-Dentin is produced by odontoblasts
-Closely packed dentinal tubules traverse the entire thickness and contain cytoplasmic extensions of odontoblasts
35
where are odontoblasts formed from
derived from neural crest cells
36
describe cementum
*Covers root of tooth, Avascular
* The central pulp chamber called pulp cavity:
-Richly vascularized, Abundant nerves
-Odontoblasts cell bodies
37
Describe the Periodontal ligament (PDL)
-Specialized connective tissue between cementum and bone
-Principal fiber groups(type I collagen fibers) insert into bone and cementum as Sharpey’s fibers
38
what is the function of the peridontal ligament and what amkes it unique?
* Tooth attachment/fixation and support
* Unlike typical ligaments:
- Highlycellular
- Rich blood supply
- Lots of nerves
- Collagen fibers have a high turnover rate (produced all the time
* Poor nutrition causes atrophy
39
why can you see vitamin c deffiency showing up in the teeth first
because of the high collagen turnover
40
what happens at the begining stages of tooth development
neural crest cells migrated into the mesoderm layer in the cranial region of the embryo and form ectomesenchyme
41
what is the Initiation phase of tooth development
A U-shaped ectoderm ridge called the primary epithelial band forms the dental lamina on upper/lower jaws
The mesenchyme of the oral cavity that has been invaded by neural crest cells is called ectomesenchyme
42
what stage of tooth development is this
bud stage
43
describe the bud stage of development
-The tooth buds grow into the underlying ectomesenchyme
-Period of cellular proliferation (rapid)
44
what stage of development is this?
the cap stage
45
describe the cap stage of oral development
-The deep surface of the bud invaginates and becomes cap shape
-enamal organ is ectoderm and gives rise to enamal
-remaining ectmesenchymal cell become dental sac
46
what does the enamel organ give rise to?
gives rise to
enamel
47
what does the dental sac give rise to?
cementum, PDL, Bone
48
what does the dental papilla give rise to?
gives rise to dentin
49
in the cap stage the enamal organ consists of what 4 components?
-outer enamel epithelium
-inner enamel epithelium
-stellate reticulum
-stratum intermedium
50
decribe what happens in the bell stage?
The under surface of the enamel organ deepens
* The enamel organ has four distinct regions:
1)Outer enamel epithelium
2) Stellate reticulum-mechanical role(protects dental tissues, produces signaling molecules, supports shape)
3) Stratum intermedium-flattened cells overlying inner enamel epithelium, role in producing proteins for inner enamel epithelium
* Inner dental epithelium-produces enamel
51
what is the cervical loop?
-Inner and outer enamel epithelium are continuous at the cervical loop
-This is where the outer epithelium bends to meet the inner epithelium
-Gives rise to the epithelium that will signal root development
52
what does the cervial loop give rise to?
hertwig's rooth sheath
53
describe the physiological erruption that takes place in tooth development
-The dental lamina begins to degenerate as each developing tooth reaches the bell stage
-The connection to the oral cavity now requires a physiological break in the lining epithelium
-programmed cell death
54
describe how ameloblasts and odontoblasts form?
-Cells of the inner dental epithelium differentiate into ameloblasts and signal the differentiation of odontoblasts from cells in dental papilla
-Cells of the dental papilla will differentiate into odontoblasts and secrete predentin which becomes dentin (dentin formation always precedes enamel formation)
55
what is reciprical induction
back and forth signalling process
56
what do ameloblasts secrete?
enamel
57
what are dentinal tubules
Long apical processes of the odontoblasts
58
label
59
what is cementum
a thin layer of hard tissue similar to bone, covering the roots of the teeth beginning at the cervial portion of the tooth (where cervial loop was)
60
where does root development begin?
at the epithelial root sheath (Hertwig epithelial root sheath)
61
how is cementum formed
When the root dentin has formed, the ectomesenchymal cells from the dental sac differentiate into cementoblasts, and produce cementum
62
what forms the PDL
Fibroblasts from the dental sac begin to form the PDL
63
what produces alveolar bone?
oateoblasts
64
label
A: crown
B: enamel
C: dentin
D: pulp
E: alveolar bone
F: periodontal ligament
G: gingiva
H: cementum
I: apical foramen
65
the oral cavity lined by epithelium gives rise to
the dental lamina and enamel organ
66
what two layers is the cementum divided into?
divided into acellular and cellular layers
67
what stage of development is this and where is everything dervived from
68
what is this and where is it derived from
stellate recticulum derived from surface ectoderm
69
what is the GAG filled extracellular fluid
the stellate recticulum
70
what kind of cells are in the inner enamel epithelium
columar cells
71
what kind of cells are in the outer enamel epithelium
cuboidaal
72
how are stellate reticulum cells linked
desmosomes
73
what are Cementocytes
Cementocytes are cementoblasts that become trapped in lacunae within the cementum.
74
label
75
label
76
label
77
Bolus
a lump of chewed and swallowed food
78
Chyme
bolus + stomach juices “a liquefied bolus”
79
Feces
undigested remnants of chyme (once chyme enters the colon)
80
what is the gut derived from?
the endoderm
81
what does the forgut turn into?
Esophagus, stomach,
proximal duodenum
82
what does the midgut turn into?
Rest of duodenum, jejunum, ileum, cecum, asc. Colon, prox. transverse colon
83
what does the hinfgut turn into
Distal transverse colon, descending colon, sigmoid colon, rectum, upper anal canal
84
what is the vascular supply of the foregut?
Supplied by Celiac axis
85
what is the vascular supply of the midgut?
supplied by superior mesenteric artery
86
what is the vascular supply of the hindgut
Supplied by the mesenteric artery
87
what is the mesentery
the point where the visceral and parietal mesoderm meet
88
describe the type of cell, and pupose of the GI tract mucosa
protection (SSNK)
absorption and/or secretion
movement of villi
89
what is the purpose of the muscularis externa of the GI tract
mechanical breakdown
peristalisis
sphincter
90
what is the mesentery
-suspends organs
-a double-fold of visceral peritoneum
-CT from organs both sides serosa + blood
of the vessels
91
omentum
the mesentery of the stomach
92
Does it have a serosa or an
adventitia?
esphagus
mostly adventitia
93
Does it have a serosa or an
adventitia?
stomach
serosa
94
Does it have a serosa or an
adventitia?
duodenum
mostly adventitia
95
Does it have a serosa or an
adventitia?
jejunum and ileum
serosa
96
Does it have a serosa or an
adventitia?
colon
varies
97
Does it have a serosa or an
adventitia?
lower rectum and anal canal
adventitia
98
Enteric nervous system
the “gut brain”
99
what is the enteric nervous system derived from?
neural crest cells
100
what parts of neurons are in the enteric neurvous system
-Cell bodies and fibers of postganglionic parasympathetic
-Cell bodies and fibers from local connections between cells (local reflexes exclude the CNS)
101
what is the organization of the enteric nervous system?
2 layers of ganglia organized into plexus
102
Myenteric plexus
branched network of interconnect fibers in CT space that controls peristalsis
103
what are the functions of the enteric neurvous system?
-Stretch receptors
-Secretion of digestive juices (stomach, liver,
pancreas)
-Peristalsis(waves of rythmic)
-Control of sphincters
-Defecation
-Local blood flow
-Immune systeminteractions
104
what do meissner's plexus do?
regulates glandular secretions and movement of villi (projections into lumen)
105
toxic megacolon
lack of development of enteric nervous system
106
hirschsprung disease
failure of neural crest cells to migrate to hindgut during development
107
chagas disease
acquired in adulthood
loss if distal neurons of the enteric neurvous system
108
what kind of epithlium is in the esophagus
SSNK
109
what kind of glands are in the esophagus?
-Cardiac glands of the mucosa
- Esophageal glands of submucosa
110
what kind of muscle is in the esophagus?
-Smooth and striated muscle in muscularis externa
-only part of the GI tube with skeletal muscle
111
what is an anatomical sphincner
a thickening
112
what is a physological sphincner
↑muscle tone
113
Mallory- Weiss syndrome and Boerhaave syndrome
-when esophagus enters the peritoneal
cavity there can be submucosal + longitudinal
tears
-a full rip is called boerhaave syndrome
114
Esophageal Submucosal Glands
*Mostly mucous cells, some serous cells
* Function similar to salivary glands
* Seromucous secretions to lubricate the lumen of the esophagus to ease passage of bolus
115
Esophageal Cardiac Glands of the
Mucosa
Located in the lamina propria and resemble cardiac glands of the stomach Secrete pH – neutral mucin
116
what is this showing
Esophagogastric Junction and
cardia of stomach
117
Barrett’s Esophagus
a metaplasia
irration of esophagus epithelium
118
Rugae
highly folded section of mucosa & submucosa
119
what are the glands of the Stomach
cardiac glands
gastric glands
pyloric glands
120
what do suface mucous cells do
keep a neutral pH and protect cells
121
what do mucous neck cells do
short with a basal flatten nuclei
more acidic mucous
122
what do perietal cells do
very eosinophilic
secret H+, intrinsic factor, Cl-
123
what do chief cells do?
basophilic
secrete pepsinogen
decreased activation by an acidic envirment
124
what do neuroendocrine cells do?
basophilic
in the base of glands
125
Gastric pits
-Lined by luminal epithelium
-Surrounded by surface mucous cells
-More superficial than glands
126
gastric glands
Branch from gastric pits, deep into the mucosa, all the way to the muscularis mucosae (but are still made of epithelium
* Contain a variety of cells (mucous, digestive,
endocrine, stem)
127
what cells are in gastic pits and glands
pits dont have periental or chief cells
128
what is the shape of a chief cell
euchromatic nuclus
low columar to cuboidal in shape
zymogen granules
129
what is the shape of perietal cells
*Large, wedge-shaped, and rounded
* Centrally located nucleus
* Most abundant in the isthmus of gastric glands
* Abundant surface area for ion pumps
* Secrete gastric acid and intrinsic factor
130
where are the gastric pits and gastric glands
131
Mucosa of Pyloric Stomach
* Glands are shallow
* Lack parietal and chief
cells
* Secrete mostly mucous
* Also contains enteroendocrine (G) cells – secrete the hormone, gastrin
132
what is special about the muscle in the stomach
Muscularis externa has a
third layer called the oblique layer(inner most)
133
what is the purpose of the Pyloric Sphincter?
restricts the movement of food
134
what are the most common cells of the intestinal epithelium?
enterocytes and goblet cells
135
what are the anatomical segaments of the small intestine
* Duodenum
* Jejunum
* Ileum
136
what are the three surface area specializations of the small intestine?
circular folds
villi
microvilli
137
what is the most efficent surface specalization?
microvilli
138
where does most digestion and absorption take place?
the small intestine
139
Epithelial Cells of Intestinal Villi
1. Enterocytes – oldest at tips of villi
2. Goblet cells – mucin
140
Epithelial Cells of Crypts of
Lieberkühn
1. Enteroendocrine cells
2. Paneth cells – secrete lysozyme
3. Stem cells
141
what do Endocrine cells secrete
hormones
142
what do paneth cells secrete
grandules to kill bacteria
143
what is a cental lacteal?
central lacteals, which are lymphatic vessels specialized to carry absorbed lipids in the form of chylomicra.
144
what is this the cross section of?
villi
145
what is the main cell of the small intestine
enterocyte
146
what absorbs fat
lacteals absorb fat
147
Hepatic Portal Circulation
Absorbed amino acids and sugars move from one capillary network in the villi to the hepatic portal vein, to the capillaries of the liver
148
duodenum key characteristics
-Circular folds less pronounced than jejunum
* Brunner Glands of submucosa
149
key characteristics of the jejunum
plain with the most prominent folds
150
key characteristics of the IIeum
has the most goblet cells
fewer circular folds
peyer's patches
151
what are peyer's patched
clusters of lymphoid follicles GALT
152
Celiac Disease causes
-Loss of villi
-increased immune cell presence (lymphocytes and plasma cells)
-Elongated crypts with increased stem cell activity
153
how are Fibroblasts involved in the intestine?
involved in pattering signal gradients that form crypts or gradients
154
Special features of the large intestine
- Rich in GALT (appendix)
- Teniae coli & haustra
155
what is the purpose of the large intestine?
The large intestine serves chiefly to absorb liquid and concentrate waste
156
does the large intestine have villi
no
157
what is this a cross section of
crypt
158
what is this pointing to
teniae coli
Thickened OLL of muscularis externa
159
what is the Structure of the Appendix
* Simple columnar epithelium
* Lacks villi
* Short crypts
* Prominent GALT in submucosa and lamina propria
* serosa
160
what is the epithelium transition at the pectinate line?
simple columnar to SSNK
161
Identify the following regions
Gastroesophageal junction
162
Identify the following regions.
fundic stomach
163
Identify the following regions.
pyloric stomach
164
Identify the following regions
Duodenum
165
Name the labeled cells and describe their functions.
Which organ is this? and which region is being studied?
A. Surface mucous cells secrete alkaline fluid containing mucin
B. Parietal cells secrete HCl and intrinsic factor
C. Chief cells secrete pepsinogen
This is the fundic stomach.
166
Q3. Which of the following is an effective strategy that the digestive system uses
to maintain a barrier between the internal milieu of the body and the external
environment?
A. Composition of saliva
B. Acidic environment of the stomach
C. Large volume of mucus produced into the lumen of the large intestine
D. Close and abundant immune defense structures and mechanism (Peyer’s
patches and GALTs)
E. All of the above
E. All of the above
167
Which of the following structure includes the submucosa?
A. Microvilli
B. Villi
C. Plicae circulares
D. Taeniae coli
C. Plicae circulares
168
what is outlined
169
this is the fundic stomach what cells are the lines pointing to?
170
this is the pyloric stomach what is this pointing to?
171
what is this pointing to?
Paneth cells with
eosinophilic granules in the
crypts of Lieberkuhn
172
where is this and what are the arrows pointing to?
jejunum
173
what is this pointing to?
plicae circulares
174
peyer's patches in the submucosa of the ileum
175
176
identify the cell
surface mucus cell
177
what is this pointing to
neurons of the enteric nervous system
178
in the duodenum what is this pointing to
bottom crypt
top brunner's glands
179
what section of the GI tract is this
appendix
