GI Tract (Exam III) Flashcards
(239 cards)
1
Q
Name of canal that extends from oral cavity to anus
A
Alimentary canal
2
Q
Five phases of food breakdown:
A
1- ingestion
2- fragmentation
3- digestion
4- absorption
5- elimination
3
Q
_____ occurs in the oral cavity, accompanied by _____; resulting in ____ formation
A
ingestion; fragmentation, bolus
4
Q
Stomach completes ______ & initiates ______
A
fragmentation; digestion
5
Q
Contractions of smooth in GI system
A
peristalsis
6
Q
Peristalsis occurs under the control of:
A
Autonomic control
7
Q
In the duodenum, what do pancreatic & biliary secretions do?
A
Emulsification of fat
8
Q
Where does emulsification of fat occur?
A
In duodenem
9
Q
What occurs in the jejunum & ileum?
A
Primary absorption of nutrients
10
Q
What occurs in the colon?
A
respiration of water & elimination of waste
11
Q
The muscular tube of the GI tract is lined by:
A
Mucus membrane
12
Q
There are a large number of ____ associated with the GI tract
A
glands
13
Q
List three glands of the GI tract
A
1- liver glands
2- pancreas glands
3- intestinal glands
14
Q
The liver, pancreas, & intestinal glands all have what in common?
A
All embryological outgrowths of the GI tract
15
Q
Diffuse lymphoid tissue scattered throughout the GI tract
A
MALT
GALT
16
Q
What are the four distinct layers of the GI tract?
A
1- mucosa
2- submucosa
3- muscularis externa
4- adventitia (serosa)
17
Q
The mucosa has three overall functions including:
A
1- protection
2- secretion
3- absorption
18
Q
Different types of mucosa are modified for:
A
Different functions
19
Q
The mucosa of the GI tract is subdivided into three layers including:
A
1- epithelium
2- lamina propria
3- muscularis mucosae
20
Q
Layer of mucosa that has secretory & absorptive functions
A
epithelium
21
Q
the ____ layer of the mucosa has different modifications at different levels of the GI tract
A
epithelium
22
Q
Layer of mucosa -thin underlying connective tissue layer
A
lamina propria
23
Q
What are some components of the lamina proprietary (4):
A
1- lymphoid nodules
2- glands
3- blood vessels
4- lymphatics
24
Q
Layer of mucosa- thin layer of smooth muscle
A
muscularis mucosae
25
The layer mucosa that acts as a boundary between the mucosa & submucosa
muscularis mucosae
26
What does the muscularis mucosae act as a boundary between?
mucosa & submucosa
27
Large numbers of ____ & ____ cells in the lamina propria
Lymphocytes & plasma cells (immune surveillance)
28
Layer of the gut- loose to dense irregular connective tissue layer beneath the muscularis mucosae
submucosa
29
Layer of the gut responsible for supporting the mucosa
submucosa
30
List the components of the submucosa
larger blood vessels, nerves & lymphatics
31
inner circular & outer longitudinal smooth muscle layers of the gut
muscularis externa
32
The muscularis externa may also be called
muscularis propria
33
The smooth muscle fibers of the muscularis externa are oriented at:
right angles to one another
34
The inner circular layer of the muscularis externa (propria) contains fibers:
fibers going circumferential around the gut
35
The outer longitudinal layer of the muscularis externa contains:
muscle fibers oriented at right angles to one another
36
The local contractions that result in mixing of food in the gut
segmentation
37
Segmentation occurs both ____ & ____ in either direction
proximally & distally
38
Propels food only in the distal direction
peristalsis
39
Overall effect is like kneading bread dough that results in mixing food with digestive secretions but NOT pushing food down the gut
segmentation
40
When talking about peristalsis another term we can use the direction that the food is pushed is _____ which means ____
aborally- meaning away from mouth toward anus
41
Describe the contractions of peristalsis
Forceful & organized
42
Outer loose connective tissue layer of the gut that contains major nerves, vessels & adipose tissue
adventitia
43
The adventitia within the abdominal cavity is referred to as:
serosa or visceral perioteneum
44
The adventitia in the gut (serosa/visceral peritoneum) is continuous with:
supporting mesentary
45
The adventitia of the gut (serosa/visceral peritoneum) is lined by:
simple squamous epithelium (mesothelium)
46
In other areas, the adventitia (serosa/visceral peritoneum) merges with:
retroperitoneal tissue
47
The smooth & shiny surface of the gut
adventitia (serosa/visceral peritoneum)
48
The smooth muscle of the gut is controlled by:
the autonomic nervous system
49
the parasympathetic stimulation of the smooth muscle of the gut results in:
excitatory
50
the sympathetic stimulation of the smooth muscle of the gut results in:
inhibitory
51
The parasympathetic motor nerves synapse with:
ganglia located near the effector organ
52
Parasympathetic nerves synapse with:
ganglia near the effector organ
53
in the GI tract, ganglia are located:
within the wall of gut (within submucosa & muscularis externa)
54
Clusters of parasympathetic ganglia within the submucosa:
Meissner's plexus (submucosal plexus)
55
What type of ganglia comprise the meissner's plexus:
parasympathetic
56
Larger clusters of ganglia located between inner circular & outter longitudinal muscular layers:
myenteric or Auerbachs plexus
57
Short, muscular tube lined by stratified squamous nonkeratinized epithelium
esophagus
58
What type of cells line the esophagus
stratified squamous nonkeratinized epithelium
59
In the upper third of the esophagus, the muscular externa is composed of:
The middle third of the esophagus is composed of:
The lower third of the esophagus is composed of:
voluntary skeletal muscle
skeletal & smooth muscle
smooth muscle only
60
Due to the muscle makeup of the esophagus swallowing occurs in the upper third made of ______ muscle so it is ______. Vomiting occurs in the lower one third of esophagus so it is ______
skeletal muscle; voluntary
smooth muscle; involuntary
61
Where is the gastropesophageal sphincter located?
gastroesophageal junction between the stomach & esophagus
62
heartburn:
pyrosis
63
pyrosis is due to regurgitation of _____ into the ______ from the cardia from the ____ of the stomach
stomach acid
distal esophagus
cardia
64
Regions of the stomach (3):
1- cardia
2- fundus
3- pylorus
65
The cardia is surrounded by a:
smooth muscle cardiac sphincter
66
the smooth muscle cardiac sphincter that surrounds the cardia is known as the:
gastropesophageal sphincter
67
Adjacent to the esophagus- contains predominantly muscous-secreting glands
cardiac sphincter (gastroesophageal sphincter)
68
The glandular portion of the stomach
fundus
69
the funds secretes (3)
1- acid
2- pepsin
3- some mucous
70
Some texts differentiate the fundus from the ______
Both are glandular but the fundus is closer to the _____ & the ____ is closer to the _____
corpus
cardia
corpus; pylorus
71
Part of the stomach containing primarily mucous & gastrin secreting glands
pylorus
72
The smooth muscle ______ controls outflow from the stomach into the duodenem
pyloric sphincter
73
Loss of stomach/duodenal epithelium/mucosa
peptic/gastric ulcer
74
an ulcer occurs when damage extends below the level of the _____ & ______ leading to bleeding
basement membrane & lamina propria
75
partial loss of the epithelium in the stomach but does not lead to bleeding
erosion
76
what is the treatment for peptic/gastric ulcers
antacids, Tagamet, cimetidine
77
the term peptic ulcers houses:
stomach & duodenal ulcers
78
ulcers are frequently associated with:
chronic infection with helicobacter pylori
79
Helicobacter pylori produce ____ resulting in _____ & secondarily leading to _____
urease; increased gastric pH; increased acid production
80
Treatment of helicobacter pylori includes:
Triple therapy
81
The triple therapy used to treat helicobacter pylori includes:
two long-term antibiotic & proton pump inhibitor
82
Distensible organ used for food storage
stomach
83
how many chambers does the stomach have in most animals?
one
84
in the stomach food undergoes mechanical breakdown via ___ & chemical breakdown via _____ to form _____
muscular activity
gastric secretions
chyme
85
In addition to the inner circular & outer longitudinal layers of the stomach, there is also a:
Third inner oblique layer in the muscular exrterna
86
little ______ occurs in the stomach
what are the exceptions:
absorption
water, alcohol, & some drugs (aspirin)
87
the stomach lining contains prominent longitudinal folds called:
rugae
88
In the glandular body of the stomach (fundus), mucosa contains prominent:
gastric pits called foveolae
89
The gastric pits in the mucosa (foveolae) of the fundus forms the entrance to:
gastric glands
90
The gastric glands of the fundus are:
straight tubular glands
91
The gastric glands of the stomach secrete around:
2 liters of watery gastric juice/day
92
The watery gastric juice secreted by the gastric glands of the stomach contains:
(what makes up the gastric juice & at what pH)
1- HCL (pH=1)
2. Pepsinogen
93
Pepsinogen is an ______ of _______
inactive precursor of pepsin
94
Pepsinogen is converted to pepsin by the action of:
HCL
95
In addition to the pepsinogen & HCL what other components are found in the gastric juices of the stomach:
gastrin
rennin
lipase
96
How can the mucosa of the stomach tolerate the harsh environment of the stomach?
protected by a thick layer of mucus
97
Gastric glands contain how many types of cells?
Name them:
5 classes
- mucous secreting cells
- acid secreting cells
- pepsin secreting cells
- enteroendocrine cells
- undifferentiated stem cells
98
The mucous secreting cells of the gastric glands look ____ on H&E
Clear
99
The mucus-secreting cells of the gastric glands cover the:
luminal surface & upper third of pit
100
How often are the mucus secreting cells removed?
Every 3-5/4-7 days
101
Type of cell that secretes thick INSOLUBLE mucous & bicarbonate ions- where are they located?
surface mucus cells
(located on surface)
102
Type of cell that secretes SOLUBLE mucous- where are they located?
mucus neck cell
(located in upper third of put, at neck of gastric gland)
103
Which mucous-secreting cells of the gastric glands have direct contact with stomach acid?
surface mucus cells
104
Acid secreting cells are a type of gastric gland cell that may also be called:
Parietal cells or oxyntic cells
105
Acid secreting cells (parietal cells/oxyntic cells) secrete: ____ & _____
HCL & intrinsic factor
106
The HCL & intrinsic factor secreted by acid secreting cells of the gastric gland is necessary for:
Absorption of vitamin B12 from the ileum
107
The acid-secreting cells (parietal/oxyntic) are most numerous in the:
middle third of the gastric gland
108
How do the acid secreting cells (parietal/oxyntic) stain?
pink to purple
109
Pepsin secreting cells can also be called:
chief cells
peptic cells
zymogenic
110
Pepsin secreting cells (Chief/Peptic/Zymogenic cells) secrete:
Inactive pepsinogen
111
Pepsin secreting cells (Chief/Peptic/Zymogenic cells) are located at:
Base of gastric gland
(bottom third)
112
Pepsin secreting cells (Chief/Peptic/Zymogenic cells) stain ____ due to _____
Purple due to large #s of ribosomes
113
Describe the lifespan of parietal & chief cells-
long lifespans, replace every one year
114
Parietal & chief cells are controlled by:
autonomic nervous system & hormones from endocrine cells in region in pylorus
115
Enteroendocrine cells can also be called _____ - what does this stand for?
APUD Cells
amine precursor uptake & decarboxylation
116
What are target cells with local vicinity
Paracrine cells
117
Secrete variety of peptide hormones in response to local factors
Paracrine cells
118
Cells that respond to local factors to accomplish control of GI motility & gastric secretion
Paracrine cells
119
Gastrin is secreted by:
G cells
120
Gastrin stimulates the secretion of ____ & ____
HCL & Pepsin
121
D cells secrete:
somatostatin
122
Somatostatin secreted by D cells inhibits:
Gastrin secretion
123
Secretin is secreted by S cells
S cells
124
What is the function of the secretin secreted by S cells
inhibits gastric secretion & stimulates smooth muscle contraction
125
Gastric glands contain _____ mainly in the neck of the gland
undifferentiated stem cells
126
Cells that continuously divide to replace lost or damaged epithelial cells
undifferentiated stem cells
127
As the undifferentiated stem cells of the gastric gland mature, they:
migrate up or down gland
128
Describe the size of the small intestine in humans
4-6 meters long
129
The small is the primary site of:
absorption & digestion
130
What are the three parts of the small intestine (in order)
Duodenum
Jejunum
Ileum
131
Mucosa & submucosa in the small intestine is arranged in valve-like folds/rings called:
Plica circulares
132
The place cirulares are also called _____ & contain a ____ core
Valves of Kerkring
Submucosal core
133
The purpose of the plica circulares in the small intestine is to:
increase the surface area
134
The mucosal surface of the small intestine is made up of:
villi
135
The core of the villi that mucosal surface of the small intestine is:
lamina propria
136
Between the villi that line the mucosal surface that line the small intestine are:
Crypts of Lieberkuhn
137
Gluten Enteropathy
Coeliac disease
138
Coeliac disease has what effect on villi, leading to what downstream effect?
villus blunting & atrophy leading to malabsorption & weightloss
139
The epithelium of the small intestine is supported by:
connective tisse lamina propria
140
The connective tissue lamina propria of the epithelium located in the small intestine contains _______ for absorption of nutrients
capillaries & lymphatics for absorbing nutrients
141
Intestinal villi are lined by:
simple columnar epithelium
142
Mucosal cells of the small intestine are called _____ and cover the surface of ___
enterocytes
villi
143
The apical/luminal surface of the small intestine is ____ & modified into _____
highly folded
microvilli
144
The microvilli of the small intestine= ___ or ____
striated or brush border
145
The microvilli of the luminal surface of the small intestine serve to:
increase surface area for absorption
146
The microvilli of the small intestine are coated with:
glycocalyx of disarcharrides (site of membrane digestion)
147
Plique, villi & microvilli all function to:
increase surface area
148
Interspersed among enterocytes are
mucous secreting goblet cells
149
The mucus secreting goblet cells synthesize _____ which later forms into _____
mucinogen
mucus
150
The mucinogen synthesized by goblet cells is stored in ____ to function to ____
membrane-bound granules that lubricate & protect the epithelium
151
At the base of the crypts of the small intestine are:
stem cells
152
The stem cells located at the base of the crypts of the small intestine primarily replace:
enterocytes
153
Entire epithelial lining of the small intestine is replaced every:
3-5 days
154
In addition to stem cells- what else is found at the base of the crypts:
paneth cells
155
What type of granules do paneth cells contain?
large eosinophilic granules
156
The large eosinophilic granules of paneth cells produce antibacterial proteins called _____ & enzymes including ____
defensins & lysozyme
157
In the small intestine scattered throughout are small numbers of ____ cells
Enteroendocrine cells (APUD)
158
The enteroendocrine cells located in the small intestine function to:
regulate GI motility & secretion
159
In the small intestine:
1. S cells secrete ____ which stimulates the release of _____ from the ____
2. I cells secrete ____ which stimulates ______ & contraction of the ____
3. A cells secrete ____ which serves to ______
4. K cells secrete ____ which is ____
1. secretin; bicarb from pancreas
2. CCK; pancreatic secretion; gallbladder
3. glucagon; raise blood sugar
4. GIP; gastric inhibitory peptide
160
In the small intestine:
1. S cells secrete ____ which stimulates the release of _____ from the ____
2. I cells secrete ____ which stimulates ______ & contraction of the ____
3. A cells secrete ____ which serves to ______
4. K cells secrete ____ which is ____
1. secretin; bicarb from pancreas
2. CCK; pancreatic secretion; gallbladder
3. glucagon; raise blood sugar
4. GIP; gastric inhibitory peptide
161
MALT is located in the ____ & ____ of the small intestine
lamina propria & submucosa
162
MALT contains _____ cells that secrete ______
plasma cells; IgA
163
The epithelium of MALT contains enlarged _____
M cells (microfold)
164
Squamoid enterocytes modified for Ag sampling & uptake of macromolecules
M cells (of MALT)
165
Dome-shaped areas grossly visible on the surface of mucosa that project into the lumen (in MALT)
Peyer's patches
166
Peyer's patches contain what type of loci:
B & T cell loci
167
The duodenum is characterized by the presence of ______ in the submucosa
Brunner's glands
168
Where are Brunner's glands located?
Submucosa of the duodenum
169
In the duodenum there is a large number of highly convoluted branched tubuloalveolar submucosal glands called:
Brunner's glands
170
The Brunner's glands secrete ___ & _____ which is unique to the duodenum
mucus & zymogens
171
The main function of the duodenum is to:
(& who helps)
neutralize gastric acid & pepsin (assisted by pancreas & gallbladder)
172
What empties into the duodenum at the major duodenal papillae:
pancreatic duct & bile duct
173
The pancreatic duct & bile duct empty into the duodenum at the:
major duodenal papilla
174
Chyme from the stomach stimulates the release of two hormones from ____ cells
What are the hormones
APUD cells
secretin & CCK
175
Both secretin & CCK released form APUD cells promote:
highly alkaline pancreatic secretion
176
Pancreatic secretions are highly alkaline due to ____ for the purpose of ____
bicarbonate
to neutralize stomach acid
177
CCK also stimulates the contraction of ____ & the release of _____
gallbladder
bile acids
178
_____ act as emulsifying agents for the digestion of lipids, to form micelles
bile acids
179
Pancreatic secretions also contain proteolytic enzymes ____ & ____ for the digestion of proteins
trypsin & chymotrypsin
180
Trypsin & chymotrypsin are _____ enzymes
Proteolytic
181
The pancreas secretes ____ & ____ for the digestion of proteins, _____ for the digestion of carbs, & ____ for the digestion of lipids
chymotrypsin & trypsin
amylase
lipase
182
Trypsin & chymotrypsin are secreted as _____ & _____ which are _____ to prevent autolysis
Trypsinogen & chymotrypsinogen ; zymogens
183
Trypsin is activated by ______ ; trypsin then activates ______
enterokinase
chymotrypsin
184
Digestion is a two step process that includes:
1- luminal digestion
2- membrane digestion
185
Involves mixing of chyme with pancreatic enzyme to result in molecular breakdown
luminal digestion
186
Involves enzymes of glycocalyx on plasma membrane of enterocytes
membrane digestion
187
Enterocytes synthesize various enzymes including (3):
peptidases
peptide hydrolases
disaccharidases
188
Enterocytes produce various enzymes but also produce various ____ for absorption of carbs & amino acids
carrier proteins
189
During digestion & absorption - ______ are initially denatured by HCL from ____ cells
protein
parietal cells
190
After proteins are denatured by HCL from parietal cells, they then get hydrolyzed by ____ into _____
pepsin
polypeptide fragments
191
After proteins are denatured by HCL from parietal cells, & then are hydrolyzed by pepsin to form polypeptide fragments, they are further acted on by ______ enzymes to form _______
pancreatic enzymes - trypsin, chymotrypsin, elastase & carboxypeptidase
small peptide fragments
192
after the digestion of proteins ______ get absorbed by enterocytes via active transport by carrier proteins
amino acids
193
Carbohydrates include:
primarily starches, poly, oligo- & disarcharrides
194
_____ hydrolyze starch into disarccharides (sucrose, lactose, maltose, isomaltose)
salivary & pancreatic amylase
195
During digestion, once the carbs have been broken down into disaccharides, they are further broken down into monosaccharides and then absorbed by ____ using ______
enterocytes
facilitated diffusion
196
AAs & monosaccharides are absorbed by ____ lining villi, transported across the epithelium, enter capillaries with lamina propria & make their way into ____ for ____
enterocytes
portal vein
liver storage
197
Lipids primarily come in the form of ____ from the diet, & are then emulsified by the action of _____
triglycerides
bile acids
198
After the triglycerides are emulsified by biles acids they are further broken down into _____ & _____ by ____
monoglycerides & fatty acids
pancreatic lipase
199
When the monoglycerides & fatty acids are formed by pancreatic lipase, this forms:
extracellular micelles
200
Micelles are absorbed by ____ then ____ into triglycerides within the enterocyte & coated with proteins & phopholipids to form _____
enterocytes
re-synthesized
intracellular chylomicrons
201
The initially triglycerides from diet that are now intracellular chylomicrons are transported across the enterocytes to _____
lacteals
202
blind-ended lymph vessels within lamina propria of villi
lacteals
203
What is the last step in the digestion & absorption of lipids?
carried to thoracic duct & general circulation
204
The large intestine includes:
Cecum
appendix
ascending
transverse
descending
sigmoid colon
rectum
205
What does the large intestine lack?
villi & plicae circulares
206
Small blind-ended sac, distal to the ileo-cecal junction
appendix
207
Used for bacterial digestion in herbivores; vestigial cecum
appendix
208
The appendix contains large amounts of:
This is active in:
submucosal MALT
Children
209
inflamed appendix & treatment
appendicitis
appendectomy
210
The primary function of the colon is:
H2O & electrolyte resorption
211
The colon produces ____ for elimination of undigested food & waste
mucus
212
in the colon, we have large numbers of _____ in the epithelium & _____ glands in the submucosa
goblet cells
colonic glands
213
What glands are NOT seen in the colon?
Brunner's glands
214
The colon lacks ____ & ___
Villi & plicae circulares
215
The mucosal epithelium of the epithelium is similar to _____ but in adults what cells are absent:
small intestine
paneth cells
216
MALT in the large intestine does NOT form:
domed Peyer's patches
217
No ____ are present in the lamina propria of the colon
lacteals
218
In the colon, epithelial cell replaced meant occurs around every 5 days from _____ located at the base of ____
stem cells
glandular crypts
219
In the colon, there are large numbers of commensal bacteria called:
coliforms
220
The outter longitudinal layer in the muscularis externa of the colon is reduced or incomplete - forming:
three longitudinal strips- Taenia coli
221
The Taenia coli in the colon are responsible for the formation of ______
haustra
222
Sacculations of large intestine
Haustra
223
GI polyps are indicative of:
ademoma
224
Any mass arising from the wall of the colon that protrudes into the lumen; generally asymptomatic & the most common sign is rectal bleeding. Treatment is surgical removal
polyps- adenoma
225
Colon cancer =
adenocarcinoma
226
____ roughage & fiber in diet can _____ colon cancer by ____ transit time & _____ GI motility
increased
decrease
decrease
increasing
227
Treatment of adenocarcinoma (colon cancer) involves:
surgical removal- may be even colon resection
228
There are new test kits for early detection of colon cancer that detect:
Antibodies
229
short, dilated terminal portion of the small intestine
rectum
230
The rectum contains ___ folds & large numbers of ____ glands
transverse rectal folds
mucus glands
231
In the rectum there is a transition of mucosa from ______ to ______ at the anal canal
simple columnar epithelium
stratified squamous epithelium
232
The anal canal contains longitudinal folds called
anal columns
233
anal columns may also be called:
columns of morgani
234
within the anal canal ____ extend in to the submucosa & muscularis externa
anal glands
235
In the rectum, branched, straight tubular glands that secrete mucous
anal glands
236
Surrounding musculature of the rectum forms:
internal & external sphincters
237
The external sphincter of the rectum is ____ while the internal sphincter is _____
external= voluntary (skeletal muscle)
internal= involuntary (smooth muscle)
238
Occasional enlargement & irritation of the submucosal veins around the anal canal
hemorrhoids
239
The external opening; exit of the GI tract
anus
