3: Digestive System Flashcards
(245 cards)
1
Q
What are the 8 functions of the digestive system?
A
indigestion, mastication, secretion, absorption, waste elimination, motility, hormonal release, chemical digestion
2
Q
What does the oral cavity include?
A
tongue, teeth, minor & major salivary glands, tonsils, lips
3
Q
What is the oral cavity lined with?
A
oral mucosa
4
Q
What are the 3 types of oral mucosa?
A
masticatory, lining, and specialized mucosa
5
Q
What is masticatory mucosa found on?
A
gingiva & hard palate
6
Q
What is the surface epithelium of masticatory mucosa?
A
keratinized (parakeratinized) stratified squamous epithelium
7
Q
What do the surface cells of the parakeratinized stratifed squamous epithelium keep?
A
their nuclei
8
Q
What is the lamina propria of the masticatory mucosa made of?
A
PAPILLARY LAYER: thick loose CT
- BV’s, nerves, sensory receptors, some Meissner’s corpuscles
RETICULAR LAYER: more dense CT
9
Q
Where are Meissner’s corpuscles found in the oral cavity?
A
lamina propria of the masticatory mucosa
10
Q
What is the lining mucosa of the oral cavity found on?
A
soft palate, underside of tongue, floor of mouth, cheeks, lips
11
Q
What is the GENERAL surface epithelium of the lining mucosa of the oral cavity?
A
nonkeratinized stratified squamous epithelium (or -nonkeratinized)
12
Q
What can OCCASIONALLY be the surface epithelium of the lining mucosa of the oral cavity?
A
parakeratinized stratified squamous epithelium
13
Q
What kind of epithelium makes up the lips, vermillion border (reddish part)?
A
keratinized stratifed squamous epithelium
14
Q
The areas of non-keratinized stratifed squamous epithelium are ______ than the areas of keratinized stratified squamous epithelium in the lining mucosa.
A
thicker
15
Q
What is the lamina propria of the lining mucosa of the oral cavity made of?
A
loose CT w/ BV’s & nerves
16
Q
What is the submucosa of the lining mucosa of the oral cavity made of?
A
more dense CT
17
Q
Where is the submucosa of the lining mucosa found?
A
most places
18
Q
What can the submucosa of the lining epithelium have?
A
minor salivary glands, sebaceous glands (mouth corners), larger BV’s amd nerves
19
Q
Where is the specialized mucosa of the oral cavity found?
A
dorsal surface of tongue
20
Q
What kind of specialized mucosa surface epithelium is found on filiform papillae?
A
keratinized stratified squamous
21
Q
What type of specialized mucosa surface epithelium is found on all papillae except filiform papillae?
A
stratified squamous epithelium
22
Q
What are the general functions of the specialize mucosa in the oral cavity?
A
move food, taste
23
Q
What is the mucosa of the tongue like?
A
thicker dorsally; thinner and smoother posteriorly
24
Q
What kind of surface epithelium is on the tongue?
A
specialized surface epithelium
stratified squamous epithelium (all other)
keratinized stratified squamous (filiform)
25
What kinds of papillae have specialized surface epitheilum?
all: filiform, fungiform, foliate, vallate (circumvallate)
26
What type of glands are associated with vallate papillae?
small salivary (von Ebner) glands
27
What is the function of von Ebner glands?
produce serous fluid to cleanse the taste buds on these papillae
28
Where are taste buds found?
on all papillae except FILIFORM papillae
29
What is the lamina propria of the tongue made of?
loose connective tissue, adipose possible
30
Is there submucosa of the present in the tongue?
usually yes; adipose possible
31
What can the submucosa of the tongue contain?
lingual salivary glands; produce serous products
32
What is unique about the intrinsic tongue muscles?
no external attachment
33
What are the 4 alternating muscles of the tongue?
superior longitudinal muscle
vertical muscles alternating w/ transverse muscles
inferior longitudinal muscle
34
What is the function of the intrinsic muscles?
change the tongue shape
35
What are the layers of the muscles outside to inside of developing teeth?
ameloblasts, enamel, dentin, predentin, odontoblast, dental papillae
36
What kind of cells are ameloblasts?
polarized columnar cells (secratory)
37
When do ameloblasts disappear?
after tooth eruption
38
What is the function of ameloblasts?
produce enamel
39
Which cells produce enamel?
ameloblasts
40
What substance is the hardest substance in the body?
enamel
41
How thick is enamel?
~2mm
42
What is enamel made of?
interlinked enamel rods
43
Can enamel be made after tooth eruption?
no
44
How hard is dentin?
harder than bone, softer than enamel
45
What does dentin contain?
thin dentinal tubules containing nerves & cell processes of odontoblasts
46
What is dentin produced by?
odontoblasts
47
What is predentin?
precursor to dentin before mineralization
48
What produces predentin?
odontoblasts
49
What are odontoblasts?
columnar cells lining the pulp cavity
50
Which cells survive into adulthood?
odontoblasts
51
What is the function of odontoblasts?
repair and produce dentin
52
What are odontoblasts precursors for?
dentin, predentin
53
What is the area of CT below odontoblasts?
dental papillae (dental pulp)
54
What does the dental papillae have in it?
many blood vessels and nerve
55
What is a potential problem with the dental pulp?
if there is an infection there is no room for expansion--> extensive inflammation
56
What are the 3 salivary gland names?
parotid, submandibular, sublingual
57
What is the largest salivary gland?
parotid gland
58
How much saliva does the parotid gland produce?
~30% of total
59
Which gland is most affected by mumps?
parotid gland
60
The facial nerve passes through which gland?
parotid gland
61
What happens to the parotid gland as we age?
it common becomes infiltrated with adipose
62
What is a potential problem with the dental pulp?
if there is an infection there is no room for expansion--> extensive inflammation
63
What are the 3 different kinds of serous products produced by the parotid gland?
salavary amylase (alpha amylase): starts carb breakdown
lipozyme (anti-bacterial)
secratory IgA
64
What is the largest salivary gland?
parotid gland
65
What can happen to the submandibular gland by midlife?
it can by infiltrated by fat
66
Which gland is most affected by mumps?
parotid gland
67
The facial nerve passes through which gland?
parotid gland
68
What does the parotid gland produce?
100% serous products
69
What are the 3 different kinds of serous products produced by the parotid gland?
salavary amylase (alpha amylase): starts carb breakdown
lipozyme (anti-bacterial)
secratory IgA
70
What percentage of the total salivary output does the submandibular gland produce?
~60% total output
71
What can happen to the submandibular gland by midlife?
it can by infiltrated by fat
72
What are the 2 mixed salivary glands?
submandibular, sublingual
73
Which gland lacks a separate serous acini?
sublingual gland
74
What does the submandibular gland contain?
serous demilunes
75
Which gland is mixed, many serous products?
submandibular
76
What is the sublingual gland?
smallest salivary gland ~5% total salivary output
77
What gland is mixed mainly mucus producing?
sublingual gland (~80%)
78
Where does all of the serous products of the sublingual gland come from?
the serous demilunes
79
Which gland lacks a separate serous acini?
sublingual gland
80
What does the mucosa of the gut include?
surface epithelium
lamina propria: loose CT
muscularis mucosa: smooth muscle (longitudinal)
81
What does the submucosa of the gut?
more dense CT
larger BV's
SUBMUCOSAL (MEISSNER) PLEXUS
82
What is the function of the Meissner plexus?
influences mucosa
83
What id the adventitia of the gut wall?
connetive tissue along longitudinal organs
84
What is the muscularis externa of the gut made of?
myenteric (Auerbach) plexus
typically smooth muscle
typically fiber orientation = inner circular & outer longitudinal layers = normal pattern
85
Where is the myeteric (AUERBACH) plexus found?
btwn the circular and longitudinal muscle layer
86
What is the function of the Auerbach plexus?
influences ME
87
What special cells does the surface epithelium of the mucosa of the esophagus?
Langerhans cells
88
What is the serosa of the gut wall?
edge of simple squamous epithelium (can include some CT) serous producing (layer of peritonium)
89
What id the adventitia of the gut wall?
connetive tissue along longitudinal organs
90
What is the function of the esophagus?
transfer bolus to stomach from the oropharynx
91
What is the surface epithelium of the esophagus mucosa?
stratified squamous
92
What are Langerhans cells?
an APC (antigen presenting hormone) with some phagocytosis possible
93
What special cells does the surface epithelium of the mucosa of the esophagus?
Langerhans cells
94
What is the lamina propria of the esophagus made of?
loose areolar CT
95
What kind of cells can the lamina propria also contain?
esophageal cardiac glands
96
What is the function of esophageal cardiac glands?
produce neutral pH mucos to protect the esophageal epithelium
97
What is the function on the esophageal proper glands?
produce slightly acidic mucus to lubricate the movement of food
98
Where were esophageal cardiac cells first found?
the last inch of the esophagus near the stomach
99
What is the muscularis mucosae of the esophagus?
discontinuous layer of longitudinal muscle
100
What is the muscularis mucosae's pattern through the esophagus?
thinner distally (by pharynx) and thicker proximally (by stomach)
101
What is the submucosa of the esophagus made of?
dense fibroelastic CT
102
What kind of glands are scattered along the length of the submucosa of the esophagus?
esophageal proper glands
103
What is the function on the esophageal proper glands?
produce slightly acidic mucus to lubricate the movement of food
104
What is the normal pattern for the muscularis externa?
inner circular and outer longitudinal layers
105
What is the muscularis externa of the esophagus made of?
with normal patterns
upper 1/3: all skeletal muscle
middle 1/3: mix of smooth & skeletal muscle
lower 1/3: all smooth muscle
106
What is the adventitia/serosa of the esophagus like?
primarily adventitia except the last 1-2" = last 1-2" (after the diaphragm)
Does pick up serosa
107
What are the two physiological sphincters of the esophagus?
pharyngoesophageal sphincter
| gastroesophageal sphincter
108
Where is the pharyngoesophogeal sphincter found?
btwn oropharynx & esophogus
109
Where is the gastroesophogeal sphincter found?
btwn esophagus and stomach (lower esophageal sphincter)
110
Which sphincter of the esophagus is prone to problems due to the abrupt tissue change?
gastroesophageal sphincter
111
What are the characteristics of physiological sphincters?
NO thickening of circular muscle in ME
pressure gradient aids movement
(muscle contractions & gravity help)
112
What are the 3 functions of the stomach?
continue digestion of carbs
storage (primary fxn)
some nutrient breakdown, mostly chemical, not physical
113
What are gastric pits?
tiny depressions in the stomach's surface
| 1 pit leads to more than one gland
114
What kind of surface epithelium is in the mucosa of the stomach?
simple columnar
115
What are the functions of the surface mucous (lining) cells of the stomach?
produce thick visable mucus (adheres to the surface)
| secretes bicarbonate ions
116
Where are the regenerative cells of the stomach found?
at the bases of pits
117
What is the lamina propria like in the stomach?
loose, vascular ct present in small amounts between glands
118
What makes up the muscularis mucosa of the stomach?
smooth muscle layer that is often arranged in 3 layers
| THERE AND WELL FORMED
119
What are the 3 smooth muscle layers of the stomach arranged like?
inner circular
outer longitudinal
outermost circular/oblique
120
What is the submucosa of the stomach like?
highly vascular
| contains: atriovenous anastomosis & Submucosal (Meissner's) Plexus
121
What is the function of the AVA in the stomach?
shut down activity and secretion FAST
122
Where is the submucosal (Meissner's) plexus in the stomach?
next to the inner circular layer of the muscle
123
What is the function of the Meissner's Plexus?
to influence the mucosa (secretion, BF, and limited muscle contractions)
124
What layer of the stomach are the Meissner's Plexus and AVA's found?
in the submucosa
125
What is the muscularis externa of the stomach like?
three muscle layers are possible (especially between cardiac region and greater curvature; all smooth muscle
126
How are the 3 layers of the muscularis externa set up in the stomach?
innermost oblique
middle circular well developed
outer longitudinal
127
Can a normal muscle pattern show up in the muscularis externa of the stomach?
yes, other than in the cardiac and greater curvature
128
Where is the Myenteric (Auerbach's) Plexus found in the stomach?
in the muscularis externa, between the circular and longitudinal layers of muscle
129
What is the function of the myeteric (Auerbach's) plexus?
to stimulate the muscularis externa
130
What layers of the serosa are found in the muscularis externa of the stomach?
all
131
What are the three regions of the stomach?
cardiac, gastric (includes body & fundus), pyloric part
132
What are the pits of the cardiac glands of the stomach like?
shorter pits wich lead to cardiac glands with a coiled base
133
What cells are found in the cardiac region of the stomach?
primarily surface mucous, some neck mucous, a few DNES and parietal cells
NO CHEIF CELLS
134
Describe the cardiac region of the stomach....
smallest region & obtain much mucus
135
What kind of cells are found in the isthmus area of the gastric glands?
surface mucus & DNES cells
136
What kind of cells are found in the neck area of the gastric glands?
parietal & neck mucus cells
137
What kind of cells are found in the base area of the gastric glands?
cheif mucus cells
138
What do the surface mucus cells of the isthmus produce?
thick visable mucus that traps bicarbonate ions
139
What is the function of the surface mucus cells of the isthmus?
protect mucosa from auto-digestion and the rougher components of chyme
140
How many DNES (enteroendocrine) cells are found in the isthmus?
a few
141
What do the DNES type D cells produce?
somatostatin (inhibits release of hormones by near by DNES cells & HCl release)
142
What do the DNES type EC cells produce?
serotonin & substance P (increases gut motility)
143
What do the DNES type G cells produce?
gastrin
144
What do the DNES type G cells stimulate?
HCl adn pepsinogen secretion, gastric motility, and regenerative cells in body of the stomach
145
What is another name for the DNES cells of the gastric gland?
enteroendocrine
146
What kinds of cells are found in the neck of the gastric gland?
neck mucous cells, regenerative cells, parietal (oxyntic) cells
147
What do the neck mucous cells do?
produce a soluble SLIGHTLY ACIDIC mucus
| fxn: lubricate gastric contents
148
What do the regenerative cells of the neck of the gastric glands do?
replace all cell types
149
What do the parietal (oxyntic) cells of the gastric glands do?
produce: very strong HCl, Gastric Intrinsic Factor (necessary for vit. B12 absorption)
150
How can chronic gastritis lead to pernicious anemia?
low # of parietal cells can lead to low amounts of intrinsic factor, which will decrease vit. B12 absorption which is necessary for RBC maturation
LOW # RBC'S
151
What DNES cells are found in the neck area of the gastric glands?
DNES: D, EC, G
152
What types of cells are found in the Base area of the gastric glands?
cheif (zymogenic) cells, parietal cells, DNES cells
153
What do the chief (zymogenic) cells produce?
```
Primarily pepsinogen (proenzyme breaking down protein & fat)
some gastric lipase to break down fats
```
154
Are there parietal cells in the base of gastric glands?
yes, some
155
What DNES cells are found in the base of gastric glands?
DNES: D, EC, G
156
What is the pyloric region characterized by?
deeper pits, very short, twisted and branched pyloric glands
157
What cells are found in the pyloric region of the gastric glands?
primarily surface mucus, DNES and parietal cells; some neck mucous cells that also produce some lysozyme
158
What is the pyloric sphincter?
ANATOMICAL SPHINCTER between the pylorus of the stomach and the duodenum
159
What are characteristics of an anatomical sphincter?
1) well developed inner circular layer of muscle in the ME
| 2) inner circular layer in ME can be INDEPENDANTLY controlled
160
What are the 3 general functions of th esmall intestines?
digestion, absorption of nutrients, produce intestinal hormones (use DNES cells)
161
What are the 3 surface area increasers in the small intestines?
plicae circulares, villi, microvilli
162
What is another name for the plicae circulares?
valves of Kerckring
163
What are the plicae circulares?
permanent folds affecting the mucosa and submucosa; found in the duodenum, jejunum, and proximal ileum
164
Where are the microvilli found in the small intestine?
on the luminal cell surface
165
What is the surface epithelium of the intestines?
simple columnar
166
What cell types are found in the mucosa of the intestines?
surface absorptive cells, goblet cells, DNES cells, regenerative cells, paneth cells, M (microfold cells)
167
What are surface absorptive cells of the intestines?
ENTEROCYTES containing microvilli
168
What do surface absorptive cells of the intestines do?
absorb water and nutrients
| terminal digestion in glycocalyx: cells produce the enzymes and absorb the monosaccharides and peptides created
169
Where are goblet cells found in the intestines?
fewest in the duodenum and most in ileum
170
How many types of DNES cells are found in the small intestines?
~11 types
171
What are the three main types of DNES cells found in the small intestines?
types I, K, S
172
What do the type I DNES cells of the small intestines do?
produces cholecystokinin (CCK): stimulates bile release from the gallbladder, and pancreatic secretion of enzymes from serous acini
173
What do the type K DNES cells of the small intestines do?
produces GIP (gastric inhibitory peptide): inhibits HCl release
174
What do the type S DNES cells of the small intestines do?
produces secretin: stimulates secretion of bicarbonate from the pancreatic ducts; also inhibits HCl release and the movement of chyme into the small intestines
175
Where are the regenerative cells found in the small intestines?
found in the crypts
176
Where are the paneth cells of the small intestines found?
at the bases of the crypts (intestinal glands)
177
What do the paneth cells of the small intestine produce?
lysozyme
178
Where are the M cells of the small intestine found?
aka: microfold cells
| found in the ILEUM epithelium over Peyer's Patches
179
What is the cell structure of the M cells of the small intestine?
large intracellular pockets; sample foreign antigens from the gut lumen & transfer antigens to lymphocytes and dendritic cells
180
What is the function of the M cells of the small intestines?
promote humoral immunity
results in plasma cells producing IgA which is then transferred to epithelial cells and released into gut lumen
important in maintaining appropriate gut flora
181
What is the lamina propria of the small intestine made of?
loose areolar CT
182
What is found with in the villus core of the lamina propria of the small intestine?
lacteals, vascular components, some longitudinal smooth muscle
183
What are lacteals?
they are lymphatic capillaries functioning in lipid absorption
184
What are the vascular components of the lamina propria?
smaller blood vessels
185
What is the importance of the longitudinal muscle?
if irritated then the muscle contracts and the villi will shorten; can lead to nutrient deficiencies if irritation is prolonged.
186
What is another name for the borders of the intestinal glands?
crypts of lieberkuhn
187
What is the muscularis mucosa of the small intestines like?
thin but present; connects to smooth muscle in villi
188
What is the general setup of the submucosa of the small intestine?
dense fibroelastic CT
| very vascular: large blood vessels
189
What is special about the submucosa of the duodenum?
Duodenal (Brunner) Glands: seromucous glands
190
What do the duodenal (brunner) glands produce?
Primary product: alkaline mucus which importantly functions to neutralize chyme
Urogastrone: inhibits HCl secretion and increase mitosis of epithelial cells
191
What structures are significant in the jejunum?
no significant structures
192
What structures are significant in the ileum?
Peyer's Patches: groups of regularly occurring large lymph nodules
Submucosal (Meissner's) Plexus: parasympathetic innervation
193
Where is the Submucosal (Meissner's) Plexus found?
close to circular muscle in the ME of the ileum
| influences the mucosa
194
What is the muscularis externa of the small intestine like?
normal pattern: inner circular, outer longitudinal
195
What is significant in the ME of the small intestines?
Myenteric (Auerbach) Plexus: stimulates the ME for peristalsis
196
Where is the Myenteric (Auerbach) plexus found?
between the circular and longitudinal layers of the ME of the small intestines
197
Where is serosa found in the small intestines?
all of the jejunum and ileum; first and last 1-2 cm of duodenum
198
Where is adventitia found in the small intestines?
vertical (ascending) portion of duodenum
199
What type of sphincter is the ileocecal valve and where is it found?
physiological & anatomical sphincter
| between the ileum & cecum of the colon
200
What is the appendix?
VERMIFORM APPENDIX
| blind pouch on the right, extending from the cecum
201
What is the surface epithelium of the appendix?
simple columnar
| w/: surface absorpptive cells, goblets, regenerative cells, and DNES cells
202
Is there a LP in the appendix?
yes
203
Describe the muscularis mucosae of the appendix?
poorly developed
204
What other stuff is significant in the appendix?
short crypts
NO villi
NO to infrequent paneth cells
205
What is the submucosa like in the appendix?
thick layer with large blood vessels
206
What are the notable features of the submucosa of the appendix?
numerous lymph nodules
207
What is the patterning of the muscularis externa of the appendix?
normal patterning but THIN
208
Is there serosa present in the appendix?
yes
209
What is the function of the appendix?
humoral immunity
| reservoir for good bacteria
210
What are the general functions of the colon (large intestine)?
primary function: absorption of water
compaction, lubrication, and elimination of feces
production of some vitamins (riboflavin, thiamin, vit. K & B12) as bacterial by-products
211
What is the surface epithelium of the colon?
simple columnar
| w/: many goblets and surface absorptive cells (colonocytes), some regenerative cells and very few DNES cells
212
What is the LP of the colon like?
typical and has intestinal glands (crypts)
213
What is the muscularis mucosae like in the colon?
typical
214
What does the mucosa of the colon lack?
villi and paneth cells
215
What is the submucosa of the colon like?
typical
216
What is the patterning of the muscularis externa of the colon?
not normal: outer longitudinal muscle is gathered into bands called teniae coli and is discontinuous
217
What are the teniae coli of the colon made of?
longitudianl muscle bands of the ME
218
What are haustra?
constant tonus of teniae coli resulting in sacculations
219
Where is the adventitia found in the colon?
ascending and descending colon
220
Where is the serosa found in the colon?
transverse and sigmoid colon
221
What is the general function of the rectum?
store fecal matter
222
What is the surface epithelium of the rectum?
simple columnar
223
The rectum and colon are very similar in what features?
straight intestinal glands w/ goblet cells
224
What makes the colon and rectum different?
The rectum has:
Transverse rectal folds
No teniae coli in ME
has adventitia
225
What are the transverse rectal fold of the rectum?
significant luminal wall folds
226
What is the longitudinal wall muscle of the rectum like?
more complete (no teniae coli in ME)
227
What is the surface epithelium of the anal canal?
transitions from simple columnar to STRATIFIED SQUAMOUS
228
What glands are found in the anal canal?
anal glands and circumanal glands
229
What are the anal glands?
extend into the SM adn produce mucus to lubricate lumen
230
What are the circumanal glands?
APOCRINE glands in the skin surrounding the anus
231
What does the mucosa and submucosa of the anal canal have?
longitudinal folds creating ANAL COLUMNS
232
What makes the anal canal prone to hemoroids?
the submucosa has bloods vessels that are prone to irritation
233
What is significant about the muscularis mucosa in the anal canal?
it disappears
234
What is the internal anal sphincter?
a thick circular layer of smooth muscle w/i the ME
235
What is the external anal sphincter?
a striated (voluntary) muscle from the pelvic floor
236
What is the luminal wall covering of the anal canal?
adventitia
237
What are the two general causes of peptic ulcer disease?
insufficient protection from HCl and pepsin
- damaged mucus coat
- too much HCl and pepsin
Helicobacter pylori
238
With a decreased luminal acidity, how fast can damaged tissues repair themselves?
1-2 months
239
What are some factors that delay healing of peptic ulcer disease?
smoking, alcohol, caffeine, calcium, asprin
| also stress and spicy foods can aggrivate an ulcer but not cause it
240
What causes gastroesophageal (esophageal) reflux?
stomach chyme backing up into the lower esophagus
241
What are possible contributing factors to gastroesophageal reflux?
chronic gastritis (inflammed stomach lining), hiatal hernia, pregnancy, incompetent lower esophageal sphincter, subluxations (problems w/ myenteric plexus?)
242
What are some ways to reduce reflux?
keep a food diary of food, spices and drinks with episodes
limit amount of food eaten at one time
do not eat less than 3 hours before bed
243
What are some problem foods with gastroesophageal reflux?
spices (pepper, garlic, onion, peppermint, cinnamon), acidic foods, acidic beverages (fruit juices, carbonated drinks, coffee, tea), fatty foods, alcohol
244
What is Barrett's Esophagus?
stratifed squamous epithelium is replaced by mucus secreting simple columnar epithelium in lower (proximal esophagus)
245
Is Barrett's esophagus acute or chronic?
metaplasia due to a chronic problem
| PRE-CANCEROUS CONDITION
