BIOL G220: Ch. 26 Flashcards
Terms and concepts from Ch. 26: Digestive System
1
Q
The digestive system includes organs that.. (5)
A
- ingest the food
- transport the ingested material
- digest the material into smaller usable components
- absorb the necessary digested nutrients into the blood stream
- expel waste products from the body
2
Q
accessory digestive organs
A
not part of long GI tube, but often develop as outgrowths of that tube
3
Q
accessory digestive organs (6)
A
teeth tongue salivary glands liver gall bladder pancreas
4
Q
digestive system functions (6)
A
ingestion digestion propulsion secretion absorption elimination
5
Q
propulsion
A
involves peristalsis and segmentation
6
Q
peristalsis
A
ripple-like wave of muscular contraction that forces material to move further along the GI tract
7
Q
segmentation
A
churning and mixing of material helping to disperse the material and mix it and combine it with digestive organ secretions
8
Q
oral cavity contains… (4)
A
cheeps, lip, and palate
tongue
salivary glands
teeth
9
Q
cheeks
A
form the lateral wall of the oral cavity and are comprised mainly of the buccinator muscles
10
Q
cheeks end anteriorly as..
A
lips
11
Q
gingivae
A
cover the alveolar processes of the teeth
12
Q
labial frenulum
A
thin, midline mucosa on the internal surface of the upper and lower lips that are attached to the gingivae
13
Q
palate
A
forms the roof of the oral cvity
14
Q
hard palate
A
anterior two-thirds of the palate comprised of bone
15
Q
soft palate
A
posterior one-third of palate; soft and muscular
16
Q
uvula
A
extending from the soft palate posteriorly, it elevates during swallowing and closes off the posterior entrance to the nasopharynx
17
Q
fauces
A
represent the opening from the oral cavity to the oropharynx
18
Q
fauces are bounded laterally by paired muscular folds: (2)
A
palatoglossal arch
palatopharyngeal arch
19
Q
palatine tonsils
A
housed by the two arches that bound fauces
20
Q
tongue
A
manipulates and mixes ingested materials during chewing and helps compress the partially digested materials into a bolus
21
Q
bolus
A
globular mass of ingested materials that can be more easily dwallowed
22
Q
lingual frenulum
A
thin, midline mucous membrane that attaches the inferior surface of the tongue and the floor of the oral cavity
23
Q
salivary glands
A
produce and secrete saliva into the oral cavity
24
Q
saliva functions (5)
A
- moistens ingested materials to become a slick bolus
- moistens, cleanses, and lubricates the structures of the oral cavity
- chemical digestion of ingested materials
- antibacterial action
- dissolves materials so that taste receptors on the tongue can be stimulated
25
saliva production rate
1-1.5 L/day
26
saliva solute components (3)
immunoglobin A
lysozyme
mucin
27
immunoglobin A
helps decrease bacterial infections
28
lysozyme
antibacterial enzyme
29
salivary glands are located..
external to the oral cavity
30
pairs of salivary glands (3)
1. parotid glands
2. submandibular glands
3. sublingual glands
31
parotid salivary glands are the __ of the three
largest
32
parotid salivary glands secrete _-_% of total saliva
25-30%
33
parotid salivary glands include a __ ___ that runs parallel to the zygomatic arch and pierces the ___ muscle
parotid duct; buccinator
34
parotid salivary glands also secrete..
amalase
35
submandibular salivary glands produce the __ of the saliva (_-_%)
majority; 60-70%
36
submandibular salivary glands contain a __ ___ that transports saliva from each gland through a papilla in the floor of the mouth
submandibular duct
37
sublingual salivary glands contribute _-_% of total saliva
3-5%
38
sublingual salivary glands contain multiple, tiny __ ___ that open into the inferior surface of the oral cavity
sublingual ducts
39
types of secretory cells found in salivary glands (2)
mucous cells
| serous cells
40
mucous cells
secrete mucin, which forms mucus upon hydration
41
serous cells
secrete a watery fluid containing ions, lysozyme, and salivary amylase
42
parotid (type of secretion)
only serous
43
submandibular (type of secretion)
both mucus and serous
44
sublingual (type of secretion)
both mucus and serous
45
teeth are collectively known as
dentition
46
a tooth has an exposed ___, a constricted __, and one or more ___ that fit into __ ___
crown; neck; roots; dental alveoli
47
dentin
forms the primary mass of the tooth; harder than bone
48
each root of a tooth is covered with..
cementum
49
enamel
covers the external surface of the dentin and forms the crown of the tooth
50
pulp cavity
center of the tooth
51
pulp
connective tissue contained in the pulp cavity of a tooth
52
root canal
opens into the connective tissue (pulp) of the tooth
53
apical foramen
opening throughwhich a root canal opens into the connective tissue
54
apical foramen has.. which are housed by the ___
blood vessels and nerves passing through; pulp
55
teeth surfaces (6)
```
mesial
distal
buccal
labial
lingual
occlusal
```
56
sets of teeth (2)
1. deciduous
| 2. permanent
57
deciduous teeth
erupt between 6-30 months, are 20 in numbers, and are often called milk teeth
58
permanent teeth
replace the deciduous teeth and are 32 in number
59
permanent teeth types (4)
incisors
canines
premolars
molars
60
incisors
most anteriorly placed, shaped like chisels, and have a single root
61
canines
posterolateral to the incisors, pointed tips for puncturing and tearing
62
premolars
posterolateral to canines, have flat crowns with prominent ridges called cusps for crushing and grinding
63
cusps (premolars)
prominent ridges for crushing and grinding
64
molars
thickest and most posterior teeth, also adapted for rushing and grinding of ingested materials
65
gingivae composed of..
dense irregular connective tissue and nonkeratinized stratified squamous epithelium
66
gingivae function
surrounds necks of teeth and cover alveolar processes
67
hard plate composed of..
bony shelf covered by dense CT and nonkeratinized stratified squamous epithelium
68
lips are covered with..
keratinized stratified squamous epithelium
69
lips function to..
close oral cavity during chewing
70
soft palate is covered with..
nonkeratinized stratified squamous epithelium
71
teeth are..
hard structures projecting from the alveolar processes of the maxillae and mandible
72
teeth function
masticate (chew food)
73
tongue is
primarily skeletal muscle and covered by stratified squamous epithelium; surface covered in papillae
74
tonsils are..
aggregates of partially encapsulated lymphatic tissue
75
tonsils function to
detect antigens in swallowed food and drink and initiate immune response if necessary
76
vestibule is..
space between cheek and gums
77
vestibule function
space between lips/checks and gums where ingested materials are mixed with saliva and mechanically digested
78
pharynx is shared by..
the respiratory and digestive system
79
pharyngeal constrictors (3)
superior, middle, and inferior
80
pharyngeal constrictors
form the wall of the pharynx and participate in swallowing
81
CN _ innervates most pharyngeal muscles
X
82
the abdominopelvic cavity is lined with moist __ membranes
serous
83
parietal peritoneum
lines the inside surface of the body walls
84
visceral peritoneum
covers the surface of internal organs within the cavity
85
intraperitoneal organs
organs completely surrounded by visceral peritoneum
86
retroperitoneal organs
organs in direct contact with the posterior abdominal and pelvic walls and are only covered on their anterolateral surfaces with visceral peritoneum
87
mesenteries
folds of peritoneum that support and stabilize intraperitoneal GI tract organs
88
blood vessels, lymphatic vessels, and nerves are sandwiched between the two fold and supply the __ organs
digestive
89
greater omentum
extends inferiorly like an apron from the greater curvature of the stomach and covers most of the abdominal organs
90
lesser omentum
conects the lesser curvature of the stomach and the proximal end of the duodenum to the liver
91
mesentery proper
suspends most of the small intestines from the posterior abdominal wall
92
mesocolon
peritoneal fold that attaches parts of the large intestine to the posterior abdominal wall
93
tunics of GI wall (deep to superficial, 4)
mucosa
submucosa
muscularis
adventitia or serosa
94
mucosa
superficial epithelium with an underlying connective tissue called lamina propria and a thin layer of smooth muscle called the muscularis mucosae
95
submucosa
composed of lymphatic ducts, mucin-secreting glands, blood vessels, and nerves including the submucosal nerve plexus
96
muscularis
two layers of smooth muscle (inner circular layer, outer longitudinal layer)
97
inner circular layer
constricts the lumen and forms sphincters
98
outer longitudinal layer
shortens the tube
99
nerve fibers and associated ganglia between the two smooth muscle layers of muscularis tunic is called the..
myenteric nerve plexus
100
adventitia or serosa
outermost layer composed of areolar CT with collagen and elastic fibers
101
serosa
same as adventitia but is covered by visceral peritoneum
102
unpaired arteries supplying the abdominal GI tract (3)
1. celiac trunk
2. superior mesenteric artery
3. inferior mesenteric artery
103
lacteals
lymph ducts that are present in villi of small intestine
104
lacteals transport lymph to..
cisterna chyli, which drains into the thoracic duct
105
MALT
mucosa-associated lymphatic tissue
106
MALT are lymphatic structures found..
in the small intestine and appendix and are called Peyer patches
107
autonomic plexuses following unpaired arteries (3)
1. celiac plexus
2. superior mesenteric plexus
3. inferior mesenteric plexus
108
esophagus
a tubular passageway that conducts ingested materials from the pharynx to the stomach
109
esophageal hiatus
opening in the diaphragm allowing passage of the esophagus as it connects to the stomach
110
esophagus length
25 cm
111
esophagus sphincters (2)
superior esophageal sphincter
| inferior esophageal sphincter
112
superior esophageal sphincter
junction of the pharynx `and the esophagus; closes during inhalation preventing air from entering the GI tract
113
inferior esophageal sphincter
junction of the esophagus and the stomach; prevents material from regurgitating from the stomach into the esophagus
114
stomach
continues the mechanical and chemical digestion of the bolus
115
bolus is eventually processed into..
chyme
116
four regions of stomach
1. cardia
2. fundus
3. body
4. pyloris
117
greater curvature of stomach
inferior border of stomach
118
inferior curvature of stomach
superior border of stomach
119
gastric folds (rugae)
internal surface of the stomach thrown into folds
120
stomach is line by..
simple columnar epithelium
121
gastric pits
numerous depressions indented within stomach lining
122
gastric glands
several branched tubular glands at the base of each gastric pit
123
secretory cells (gastric epithelium, 5)
1. surface mucous cells
2. mucous neck cells
3. parietal cells
4. chief cells
5. enteroendocrine cells
124
surface mucous cells secrete..
alkaline mucin for protection and armor (thick)
125
mucous neck cells secrete..
acid mucin that helps break down food (thin)
126
parietal cells secrete..
hcl
127
chief cells secrete..
pepsinogen and lipase
128
enteroendocrine cells secrete..
hormone gastrin
129
small intestine
finishes the chemical digestion process and is responsible for absorbing most of the nutrients
130
ingested materials spend at least _ hours in the small intestine as chemical digestion and absorption are completed
12
131
segments of small intestine (3)
1. duodenum
2. jejunum
3. ileum
132
duodenum
c-shaped portion found in the upper right quadrant of the abdomen; is continuous with jejunum at duodenojejunal flexure and contains the major duodenal papilla
133
duodenal papilla
site where bile and pancreatic secretions enter the duodenum
134
jejenum
middle portion of the small intestine that is primary region for chemical digestion and nutrient absorption
135
ileum
last segment of the small intestine with its distal end terminating at the ileocecal valve
136
ileocecal valve
a sphincter that controls the entry of materials into the large intestine
137
circular folds
folds of mucosal and submucosal tunics in small intestine
138
villi
microscopic fingerlike projections seen on the surface of circular folds
139
microvilli
microscopic fingerlike projections seen on the surface of the villli (apical surface of columnar epithelial cells)
140
circular folds function to..
slow down the passage of materials undergoing digestion; increases surface area for both absorption and chemical digestion
141
villi function
increase surface area for absorption and chemical digestion
142
microvilli
increase surface area for both absorption and digestion
143
intestinal glands
invaginations into mucosa between villi
144
intestinal glands (function)
increase surface area for both absorption and chemical digestion; enteroendocrine cells lining intestinal glands secrete digestive hormones
145
submucosal glands
coiled tubular glands within submucosa with ducts opening into intestinal lumen
146
submucosal glands function
secrete alkaline mucin to protect and lubricate lining of small intestine
147
large intestine
forms three-sided perimeter around the centrally located small intestine
148
large intestine function (2)
absorbs fluids and ions and compacts undigestable wastes and solidifies them into feces; stores feces until defecation
149
large intestine structures (7)
```
cecum
ascending colon
transverse colon
descending colon
sigmoid colon
rectum
anal canal
```
150
cecum
first part of large intestine; blind sac located in lower right quadrant of abdomen
151
ileocecal valve represents..
junction between small intestine and large intestine
152
acsending colon
originates at the ileocecal valve and ascends right side of the abdomen
153
right colic flexure (hepatic flexure)
90-degree turn toward left side of abdominal cavity of the ascending colon
154
transverse colon
originates at the right colic flexure and approaches the spleen in the upper left abdominal quadrant
155
transverse colon is suspended by..
transverse mesocolon
156
left colic flexure (splenix flexure)
transverse colon making 90-degree turn inferiorly
157
descending colon
originates at the left colic flexure and makes contact with iliac fossa and termiantes into the sigmoid colon
158
sigmoid colon
shape resembles the letter S; turns inferomedially and is sudpended by the sigmoid mesentery
159
sigmoid colon terminates at the ..
rectum
160
rectum
muscular tube that readily expands to store accumulated fecal material prior to defecation
161
rectal valves
three thick, transverse folds of the rectum that ensure fecal material is retained during the passage of gas
162
rectum terminates at the..
anal canal
163
anal canal
terminal few centimeters of the large intestine
164
anal columns
lines the internal surface of the anal canal
165
internal and external anal sphincters
open and close the anal canal during defecation
166
large intestine is lined with
simple columnar epithelium and goblet cells, which secrete mucin to lubricate the fecal material
167
longitudinal muscle is incomplete in large intestine and form bundles called..
teniae coli
168
teniae coli bunch up the large intestine into many sacs collectively called..
haustra
169
omental appendices
lobules of fat extending off the external surface of the haustra
170
lobes of liver (4)
1. right lobe
2. left lobe
3. caudate lobe
4. quadrate lobe
171
structures found on inferior surface of liver (5)
```
inferior vena cava
ligamentum venosum
gall bladder
round ligament
porta hepatis
```
172
porta hepatis
where the blood and lymph vessels, bile ducts, and nerves enter and leave the liver
173
portal triad
bile ductule, branch of hepatic portal vein, brain of hepatic artery
174
gall bladder
functions to store and concentrate bile
175
cystic duct
connects the gall bladder to the common bile duct
176
pancreas
has both endocrine and exocrine functions
177
exocrine functions of pancreas
involve secreting digestive enzymes and bicarbonate, collectively called pancreatic juices, into the duodenum via the pancreatic ducts
178
biliary apparatus
network of thin ducts that transport bile from liver and gall bladder to duodenum
179
left and right lobes of the liver drain bile into the..
left and right hepatic ducts
180
left and right hepatic ducts merge to form the..
common hepatic duct
181
cystic duct and common hepatic duct merge to form..
common bile duct
182
common bile duct and main pancreatic duct enter the duodenum through the..
hepatopancreatic ampulla
183
intraperitoneal or retroperitoneal/serosa or adventitia:
| cecum, ascending colon, transverse colon, descending colon, sigmoid colon, rectu,
cecum - intraperitoneal (serosa)
ascending colon - retroperitoneal (adventitia)
transverse colon - intraperitoneal (serosa)
descending colon - retroperitoneal (adventitia)
sigmoid colon - intraperitoneal (serosa)
rectum - retroperitoneal (adventitia)
