HISTOLOGY Flashcards
(193 cards)
1
Q
In contact with the lumen, which layer do we find?
A
Mucosa
2
Q
The submucosa is formed by
A
Connective tissue
3
Q
After submucosa, which layer do we find?
A
Muscularis, after it we find adventitia/serosa
4
Q
gastroesophageal reflux, what does it mean?
A
Food is moving up from the esophagus. The esophagus does not have protection from acids and it is being damaged.
5
Q
What type of epithelium do we find in the esophagus?
A
Stratified squamous epithelium
6
Q
Define what you see in this image
A
7
Q
Muscle in the digestive system allows…
A
Contraction for food movements.
8
Q
Mucosa of esophagus is composed of epithelium, laminate propia and …
A
Muscularis mucosa
9
Q
Function of Muscularis mucosa in mucosa of esophagus
A
Contraction that allows that all food content is in touch with the epithelial cells of the organ and we guarantee that nutrients are absorbed. We also make sure that the content is mixed up.
10
Q
Which organ is this one?
A
11
Q
What structure is this? Describe it
A
12
Q
Name the following structures
A
13
Q
Difference between the upper part and the lower part of the esophagus.
A
There is a difference in the Muscularis: in the upper part we find striated skeletal muscle (with striations and sarcomeres, as well as multinucleated cells), in the bottom part smooth muscle (no striations, cells connected through dense bodies, mononucleated).
14
Q
Epithelial cells in the mucosa of the esophagus is connected by…
A
Desmosomes
15
Q
Function of basal cells in mucosa…
A
Regeneration
16
Q
What do we find in this photo, in the middle?
A
17
Q
What is a plexus?
A
Several nerves outside de nervous system.
18
Q
Possible cause of death?
A
The physiological sphincter of this patient is not working.
If the patient has a large meal, and then they lay down, the food will move upwards and the esophagus will be irritated. The food can move to the trachea and the respiratory airways can be blocked.
Possible cause of death: LACK OF O2.
19
Q
Gastric duodenum sphincter is a … sphincter
A
Real (it has muscle)
20
Q
Glands are deep. The upper part of the gland produces …., and lower parts produce…
A
Mucous, acids
21
Q
The stomach is a mixed … organ: food digestion and hormones secretion. Which hormones does it secrete?
A
Exocrine-endocrine.
Hunger hormones.
22
Q
Scanning electron microscope GASTRIC MUCOSA
A
23
Q
Main layers of walls of the digestive tract
A
24
Q
Name the structure and its parts
A
25
Name the parts of the oral cavity
Tongue, teeth, major and minor salivary glands, tonsils.
26
Name the structure
27
The tongue is covered by a nonkeratinizing … supported by a lamina propria associated with interlacing bundles of striated muscle
… extend across the laminate propria and the muscles
stratified squamous epithelium, serous and mucus glands.
28
Name the structure
Tongue
29
Name the structure
X-section of the tongue
30
Name the structure
31
Name the structure
32
Name the structure
33
What types of mucosa do we find in oral mucosa?
1. Lining Mucosa: lip, cheek, floor of mouth, soft palate, ventral surface of tongue
Epithelium - non-keratinized
Submucosa contains salivary glands
2. Masticatory Mucosa: gingiva, hard palate
Epithelium - keratinized or parakeratinized
Submucosa - absent
3. Specialized Mucosa: dorsal surface of tongue
1. FiliformPapillae–keratinizedepithelium
2. FungiformPapillae-non-keratinizedepithelium
3. (FoliatePapillae)-rudimentaryinhuman
4. Circumvallate Papillae – non-keratinized epithelium
with associated taste buds and von Ebner’s salivary glands
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Saliva stimulation is carried out by…
The autonomic nervous system
36
Composition of saliva
Water ions, glycoproteins, proteins, cells (dequamated epithelial cells and leukocytes), pH of 7.
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Myoepithelial cell
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Submandibular and sublingual glands
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Parotid gland
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Serous (parotid) acinar cells
44
What can we see in this image?
Exocytosis
45
In the hypotonic section of striated ducts in saliva production,…
46
Name the following parts of the esophagus
47
Length of the esophagus
25 cm
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Name the structure and its parts
Esophagus
49
In the upper one third of the esophagus we find… muscle
Striated
50
In the middle third of the esophagus we find… muscle
Striated and smooth
51
In the distal third of the esophagus we find… muscle
Smooth
52
Esophagus, mucosa.
53
Along the esophagus we can find several…
Lymphoid aggregations
54
Esophagus, mucosa
55
1. Submucosa
2. Submucosal glands
56
1. Muscularis externa
2. The middle third of the esophagus
57
1. The distal third of the esophagus
2. Myenteric (Auerbach’s) plexus
3. Ganglion
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1. Myenteric plexus (Auerbach’s)
2. Adventitia/Serosa
59
The esophagus is lined by a … epithelium
Stratified squamous nonkeratinized
60
In the lamina propria of the esophagus we find…
Mucus-secreting esophageal cardiac glands
61
The muscularis mucosae of the esophagus is a …
Longitudinal layer of smooth muscle
62
In the submucosa of the esophagus we find…
Mucus-secreting esophageal glands
63
Striated muscles are controlled by …
The vagus nerve
64
Smooth muscles are controlled by nerve fibers derived from…
The enteric nervous system
65
The muscularis externa has…
Peristaltic activity: it moves bolus of food from the pharynx into the stomach
66
The esophagus has two physiological sphincters:
pharyngoesophageal and the gastroesophageal
67
Adventitia or serosa is located…
After entering the abdominal cavity (the visceral peritoneum)
68
In the mucosa of the esophagus we find… glands, in the submucosa …
Esophageal cardiac, esophageal glands proper.
They secrete mucus to lubricate and protect the luminal wall.
69
Sphincter which is physiological, we do not have muscles which contract it (it is the diaphragm what closes it).
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Esophageal cardiac glands are:
- similar to cardiac glands of the …
- found in…
- present in the … part of the esophagus
- stomach
- the lamina propria of the mucosa
- terminal
72
Mark the regions of the stomach
73
When empty the stomach:
Rugae. It has longitudinally directed folds that flatten when the stomach is filled with food.
74
The gastric glands of the stomach mucosa deliver their secretions into the bases of…
Gastric pits
75
Gastric mucosa is formed by… epithelium. And there is a very small number of …
Simple columnar (composed of mucinogen-producing surface lining cell).
Taste cells.
76
Small intestine has villi: folding of…
Mucosa
77
In the submucosa of duodenum we find…
Glands
78
Small intestine is … m long
7
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The 3 regions of small intestine are…
the duodenum (proximal), jejunum (middle), and ileum (distal)
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Functions of small intestine
Function: (i) several hormones secretion; (ii) it continues and largely completes the digestion of foodstuffs and absorbs the resulting metabolites
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Function of crypts (small intestine)
Regeneration: cells regenerate and they differentiate from the base to the top
82
Fat is accumulated in the small intestine between … and then it goes to the lymphatic system (it has a different way of being reabsorbed).
LACTEALS
83
Which cells protect the small intestine from bacteria in the lumen?
Paneth cells, located in the crypts.
84
What characterises the large intestine are the villi (T/F)
False, what characterises the small intestine are the villi. The large intestine is flat.
85
The large intestine mostly absorbs…
Water
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Mucous cells in gastric mucosa produce mucus which has the following functions:
Protection: (1) against abrasion from rougher components of the chyme, (2) from the acidic content of the gastric juice (high bicarbonate and potassium concentration).
With prostaglandins (an important role in protecting gastric mucosa).
89
The laminate propria of gastric mucosa contains…
GASTRIC GLANDS
90
Gastric mucosa: luminal surface
91
Structure of the glands of gastric mucosa
- Simple, branched, tubular glands in the lamina propria of the cardia, fundus, and pylorus
- Each gland consists of an isthmus, which connects the gland to the base of a gastric pit; a neck; and a base
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Typically, several gastric glands open into…
A single gastric pit
93
Cell types found in gastric glands
1. Mucous neck cells
2. Chief cells, which produce acids
3. Parietal cells (oxyntic cells), which absorbe vitamin B12.
4. Enterochromaffin-like cell and G cells are enteroendocrine (APUD) cells
5. Undifferentiated adult stem cells
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Characteristics of mucous neck cells
- Located in the neck of the gland
- Short microvilli, apical mucous granules, a prominent Golgi complex, numerous mitochondria, and some basal RER
- Produce soluble mucus: a slippery substance that lubricates the lining of the stomach
97
Mucous (mucigen) granules accumulate in the … of mucous surface cells.
apical cytoplasm
98
Mucous surface cell
99
1. Chief cells
2. Parietal cells
100
Which kind of cell has a lightly eosinophilic cytoplasm that appears granular due to the presence of many mitochondria?
Parietal cells
101
Parietal/ oxyntic cells are … cells concentrated in the upper half of the gland.
Pyramidal
102
What do parietal cells secrete? (Necessary for absorption of vitamin B12 in the ileum)
Hcl and gastric intrinsic factor
103
What is the intracelljlar tubulo-vesicular system of parietal cells?
many mitochondria + secretory intracellular canaliculi (deep invaginations of the apical plasma membrane) lined by microvilli
When the parietal cells are stimulated to secrete HCl, the number and length of microvilli increase and the complexity of the tubulovesicular system decreases
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Parietal cells
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Chief cells
106
Chief/zymogenic cells are … cells in the lower half of the gland
Pyramidal
107
Whip king of cells secrete pepsinogen (a precursor of the enzyme pepsin) and the precursors of two other enzymes: rennin and lipase?
Chief/zymogenic cells
108
Which cells have abundance of basal rough endoplasmic reticulum (RER), a supra-nuclear Golgi complex, and many apical zymogen (secretory) granules?
Chief/zymogenic cells
109
Chief cells
110
More than a dozen types of cells that house many small hormone-containing granules, usually concentrated in the basal cytoplasm: name the type of cell (found in fundic glands)
Diffuse Neuroendocrine System (DNES) Cells
111
Enteroendocrine cell (fundic gland)
112
Which kind of cells of fundic glands are located primarily in the neck and isthmus and replace all the epithelial cells of the gland, gastric pit, and luminal surface?
Regenerative cells
113
Cardiac and pyloric glands differ in fundic glands that…
They are coiled tubular mucus-secreting glands and they lack chief cells
114
Cardiac glands
115
Which glands are mainly composed of mucous cells and are adjacent to the cardio-esophageal junction?
Cardiac glands
116
Cardiac glands
117
- HOMOGENEOUS population of mucous cells that are similar in appearance to those in cardiac glands
- The pits are much deeper compared to cardiac glands
- Stem cells and endocrine cells are also present. Parietal cell may be also found.
Pyloric glands
118
Pyloric glands
119
Gastric juice components
- Water and electrolytes
- Hydrochloric acid (HCl)
- Pepsin (converted from pepsinogen
produced by the chief cells)
- Mucus
- Intrinsic factor (a glycoprotein secreted by parietal cells that binds to vitamin B12)
- Gastrin and other hormones and hormone- like secretions: produced by enteroendocrine
cells and secreted into the lamina propria à circulation or act locally
120
Who carries out the regulation of gastric secretion?
The vagus nerve and several hormones
121
We can find a large number of lymphocytes and plasma cells in the … between the… , and, in some areas, aggregated as lymphoid nodules
Lamina propria, gastric glands
122
Pyloric sphincter muscle, muscularis externa
123
Cardiac
124
Pyloric
125
Fundus
126
Make a scheme of the general structure of the histology of the digestive system
127
Scheme of the histology of the esophagus and the stomach
128
One of the main problems that appear in the stomach is…
GASTRITIS
129
Main liver functions
Blood filtering and bile production
130
In every apex of the hexagon of liver we find…
A portal triad. Blood will pass between hepatocytes to be filtered.
131
Bile leaves the liver from the…
Portal triad
132
Liver parenchyma is formed by…
Hepatocytes and sinusoids (capillaries which are fenestrated).
133
Hepatocytes in the liver are one next to another forming a line, separated by white lines which are the…
Sinusoids (fenestrated capillaries)
134
Portal triad is formed by…
135
Kupfer cells are…
Liver macrophages
136
What can be seen in this image?
Small intestine
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138
Name the structure and its parts
The small intestine
1. Mucosa
2. Submucosa
3. Muscularis
139
Name the structure of the mucous membrane in small intestines
They are circular or semilunar folds (PLICAE CIRCULARES), consisting of mucosa and submucosa to increase the absorptive area.
Best developed in the jejunum.
140
Name the structure of the mucous membrane in small inestines
Villi: finger-like projections consisting of lamina propria connective tissue with microvasculature and lymphatics, covered with a simple columnar epithelium composed of absorptive enterocytes and goblet cells
141
Name these structures in the mucous membrane of small inestines
1. Columnar and goblet cells
2. Brush border with microvilli
142
Name these structures found in the mucous membrane of small intestines
Short tubular intestinal glands or crypts (intestinal crypts or crypts of Lieberkühn): between the villi the covering epithelium.
We find stem cells for the epithelium and Paneth cells (prevent intestinal flora from becoming concentrated in these glands where damage to the stem cells could occur)
143
Name the structure in the mucous membrane of small intestines
Mitotic figure.
Stem cells differentiation occurs in the base of this mucous membrane: cells continue to move up each villus and within a week are shed at the tip, with billions shed throughout the small intestine each day
144
Plicae circulares (valves of Kerckring) are…
permanent spiral folds of the mucosa and submucosa. Present in the distal half of the duodenum, the entire jejunum, and the proximal half of the ileum. They increase the surface area twofold to threefold
145
Intestinal villi are…
permanent evaginations:
connective tissue core (lamina propria) + numerous plasma cells and lymphocytes, fibroblasts, mast cells, smooth muscle cells, capillary loops, and a single lacteal (blind- ended lymphatic capillary). Villi increase the surface area 10-fold
146
Microvilli in small intestine are…
actin filaments that interact with myosin filaments in the terminal web. Microvilli increase the surface area about 20- fold
147
Goblet cells small intestine
148
Name the structures and where it is found
Goblet cells of the mucous membrane of small intestine
( Crypts-1 can be seen)
Recordatorio: crypts are stem cells for the epithelium and Paneth cells
149
Describe the epithelium of the mucosa of small intestines
Simple columnar – composed of goblet cells, surface absorptive cells, and some DNES cells
150
Goblet cells are … glands – produce …, which converts into…
Unicellular, mucinogen, mucin
151
Name these structures found in the epithelium of the mucosa of small intestines
ENTEROCYTES= ABSORPTIVE CELLS
(Columnar cells with brush border and microvilli)
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Name these structures found in the epithelium of the mucosa of small intestines
Surface absorptive cells
153
…(in epithelium of the mucosa of small intestines) are tall columnar cells with a layer of closely packed microvilli (striated border) on their free apical surface, glycocalix and well-developed tight junctions and zonula adherens
SURFACE ABSORPTIVE CELLS
154
ENTEROCYTES of small intestines contain:
- … bound to the microvilli which hydrolyze the disaccharides and dipeptides into monosaccharides and amino acids that absorbed through active transport
- … which carry out the digestion of fats. In humans, most of the lipid absorption takes place in the duodenum and upper jejunum
- Disaccharidases and peptidases
- pancreatic lipase and bile
155
Enterocytes in small intestine involved in lipid absorption accumulate many small lipid droplets in vesicles of the smooth ER
These vesicles fuse near the nucleus, forming larger globules that are moved laterally and cross the cell membrane to the extracellular space (arrows) for eventual uptake by lymphatic capillaries (…) in the lamina propria
LACTEALS
156
DNES cells in the epithelium of intestinal mucosa produce and secrete…, and several other hormones
They also are involved in signaling the beta cells to release insulin once sweet taste is detected in the lumen
gastrin, cholecystokinin, gastric inhibitory
peptide
157
Name the structure
DNES Cells of epithelium of intestinal mucosa
158
Name the structure
Argentaffin cells (enteroendocrine cells which react with silver)
159
Name these parts of small intestine
1. Lumen
2. Epithelium (columnar cells with microvilli).
3. Goblet cells
160
Lamina propria of small intestines is formed by…
The cores of the villi + the interstices between the numerous glands (crypts) of Lieberkühn.
- Loose connective tissue with lymphoid cells, fibroblasts, mast cells, smooth muscle cells, nerve endings, and lymphoid nodules
- Lacteals (blind-ended lymphatic vessels) + capillary loops
161
Name the marked structure
Submucosa of dudodenum with glands
162
The … are simple tubular glands, from the intervillous spaces to the muscularis mucosae of the intestine
They are composed of goblet and oligomucous cells, columnar cells (similar to surface absorptive cells), DNES cells, regenerative cells, Paneth cells, intermediate cells, and M cells
Crypts of Lieberkühn
163
… found in the crypts of small intestines protect the intestine from bacteria in the lumen.
Crypts of Lieberkühn
164
Name the marked structure
Paneth cell
165
… are located at the base of the crypts of Lieberkühn.
They are pyramidal cells which secrete the antibacterial enzyme lysozyme stored in large, apical, membrane-bounded secretory granules.
They also release other antibacterial agents, defensins and tumor necrosis factor with the capability of killing bacteria as well as certain protozoa
PANETH CELLS
166
… cells and … cells are found in the crypts and have regenerative properties.
Regenerative and intermediate
167
Name the structures and their location
White spots in serosa of small intestines called PEYER’S PATCHES (lymphoid nodules that can be seen macroscopically).
168
Structure in intestines
GERMINAL CENTERS
169
In the … of small intestines we find an inner circular and an outer longitudinal layer of smooth muscle
MUSCULARIS MUCOSAE
170
Name the region shown in the image and the structure marked
Muscularis mucosae of small intestines and the marked structure is a plexus
171
Submucosa of small intestines is composed of… and (only in duodenum) contains….
fibroelastic connective tissue,*Brunner glands* with an alkaline fluid (protects the duodenal epithelium
from the acidic chyme) and urogastrone (a polypeptide hormone - human epidermal growth factor - that enhances epithelial cell division and inhibits gastric HCl production)
172
… is housed between the two layers of muscularis externa in small intestines
Auerbach (myenteric) plexus
173
1. Submucosal plexus
2. Myenteric plexus
174
Name the marked structure
Submucous plexus of small intestines
175
External Layer of Small Intestines
- … covers all of the jejunum and ileum and part of the duodenum
- … covers the remainder of the duodenum
Serosa
Adventitia
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177
Name the structure
Large intestine (no villi)
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In the mucosa of the large intestine there are villi and specialised folds (T/F)
False
180
Describe the epithelium of the mucosa of cecum and colon
simple columnar with numerous goblet cells, surface absorptive cells, and occasional DNES cells
181
The lamina propria of the large intestine is similar to that of the small intestine: lymphoid nodules, blood and lymph vessels, and closely packed crypts of Lieberkiihn, which lack …
Paneth cells
182
Name the structure
Mucosa of large intestines
183
In the muscularis mucosa of cecum and colon we find…
an inner circular and outer longitudinal layer of smooth muscle cells
184
MUSCULARIS EXTERNA OF LARGE INTESTINE
It has an inner circular and a modified outer longitudinal layer of smooth muscle
- The outer layer: three flat, longitudinal ribbons of smooth muscle - the …
- When continuously contracted: the teniae coli form sacculations of the wall: the …
teniae coli
haustra coli
185
EXTERNAL LAYER OF LARGE INTESTINES
- …: the ascending and descending portions of the colon
-… : the cecum and the remainder of the colon.
- Fat-filled outpocketings of the … (appendices epiploicae) are characteristic of the transverse and sigmoid colon
- adventicia
- Serosa
- serosa
186
The lumen of the large intestine contains
Body’s microbiome
187
The rectum is similar to the colon but contains fewer and deeper…
crypts of Lieberkühn
188
The Anal Canal
- Constricted continuation of the rectum
- Anal mucosa: longitudinal folds called anal
columns (or rectal columns of Morgagni),
which join each other to form anal ….
The regions between adjacent valves: …
- Epithelium:…
- valves
- anal sinuses
- simple columnar
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190
Name the structure
Central vein
191
….are pyramidal serous cells arranged around a central lumen (pancreas)
Pancreatic acinar cells
192
During aging, the number of adipocytes in the pancreas…(increases/decreases), which causes…
Increases, diabetes
193
Name the organ and why you see it
Exocrine pancreas
We can see centroacinar cells: initial portion of the duct that extends up into the acinus
