Mace - Digestion Flashcards
1
Q
fxn’s of GI tract (6)
A
ingestion
motility
secretion
digestion
absorption
elimination
2
Q
mechanical ingestion breaks __ bonds
A
H
3
Q
chemical digestion breaks __ bonds
A
covalent
4
Q
GI organs (7)
A
oral cavity
pharynx
esophagus
stomach
SI
LI
anus
5
Q
accessory digestive organs (5)
A
teeth
tongue
salivary glands
liver
gallbladder
pancreas
6
Q
the pancreas and liver are referred to as accessory glands bc
A
food does not pass thru them
7
Q
layers of the GI tract - deep to superficial
A
mucosa
submucosa
muscularis externa
serosa or adventitia
8
Q
the mucosa consists of the (3)
A
epithelium
lamina propria
muscularis mucosa
9
Q
the submucosa consists of (4)
A
connective tissue
blood vessels
lymphatic vessels
nerves
10
Q
2 layers of the muscularis externa
A
inner circular m
outer long m
11
Q
serosa/adventitia
A
visceral peritoneum in abd cavity → serous membrane
thorax
around rectum/anus
retroperitoneal parts in abd
12
Q
other defined structures of GIT (2)
A
enteric NS
mesenteries
13
Q
the serosa is continuous w. the
A
mesentery
14
Q
what passes through the mesentery
A
vein
artery
lymph vessel
15
Q
the enteric ns consists of (2)
A
submucosal n plexus
myenteric n plexus
16
Q
the enteric ns can fxn __
A
independent of CNS
17
Q
layering formed by parietal and/or visceral peritoneum
A
mesenteries
18
Q
mesenteries of GIT (4)
A
greater omentum
mesentery proper
lesser omentum
mesocolon
19
Q
histology of GIT wall
A
20
Q
how are the contents of the GI tract “mixed”
A
segmentation of muscularis
21
Q
extrinsic salivary glands are sensitive to (3)
A
touch
smell
taste
22
Q
extrinsic salivary glands are innervated by
A
SNS
PSNS
23
Q
3 extrinsic salivary glands of the GIT
A
parotid
sublingual
submandibular
24
Q
parotid gland secretes __%
A
25
25
submandibular gland secretes \_\_%
65
26
intrinsic salivary glands are __ cells
in the __ lining of the mouth
that secrete at a __ rate
single
mucosal
constant
27
intrinsic salivary glands (3)
lingual
labial
buccal
28
gland anterior to and somewhat inferior to the ears - between the skin of the cheeks and the masseter m
parotid
29
gland in the floor of the mouth on the inside surface of the mandible
submandibular
30
gland in the floor of the mouth inferior to the tongue
sublingual
31
clear, watery serous fluid rich in salivary amylase
secretion of parotid gland
32
some serous fluid w. some mucus; more viscous than parotid secretion
secretion of submandibular gland
33
primarily thick, stringy mucus
secretion of sublingual glands
34
which gland is made up of many separate ducts
sublingual glands
35
which salivary gland ducts open inferior to the tongue near the frenulum
submandibular gland ducts
36
which salivary gland ducts pass thru the buccinator m and enter the mouth opposite the second molars
parotid gland ducts
37
deglutition is same-same
swallowing
38
3 phases of deglutition
1. voluntary
2. pharyngeal
3. esophageal
39
voluntary phase of deglutition is same-same
buccal phase
40
bolus of food is pushed by the tongue against hard palate → then moves toward the oropharynx
voluntary/buccal phase of deglutition
41
soft palate and uvula elevate and close nasopharynx → bolus moves into oropharynx
pharyngeal phase
42
in the pharyngeal phase, what structures close off the nasopharynx (2)
soft palate
uvula
43
in the pharyngeal phase of deglutition, the __ elevates
so that the __ closes over the laryngeal opening
larynx
epiglottis
44
soft palate, uvula, and epiglottis return to preswallowing position
superior esophageal sphincter closes
inferior esophageal sphincter opens
esophageal phase of deglutition
45
storage capacity of stomach: \_\_
stomach contents exit in __ ml portions
4L
3 mL
46
the lesser curve of the stomach connects to the
the greater curve of the stomach connects to the
lesser omentum
greater omentum
47
3 layers of the stomach
longitudinal
circular
oblique
48
the myenteric n plexus is between the \_\_
and __ muscle layers of intestine
in the __ layer
longitudinal and inner
muscularis externa
49
the submucosal n plexus is located in the ___ layer
submucosal
50
where does the stomach wall switch from simple columnar to simple cuboidal
lamina propria of mucosal layer
51
gastric pit and gastric gland
52
which gastric cell secretes alkaline fluid containing mucin
surface mucous cell
53
fxn of mucin
protects stomach wall
54
gastric cell that secretes acidic fluid containing mucin
mucous neck cell
55
gastric cell that secretes intrinsic factor and HCl
parietal cell
56
gastric cell that secretes pepsinogen and gastric lipase
chief cell
57
gastric cell that secretes gastrin into the blood
G-cell
58
the mucous membrane of the stomach secretes __ juice
from __ gastric glands
gastric
tubular
59
how is pepsin formed
from pepsinogen in the presence of HCl
60
fxn of pepsin
protein splitting enzyme
61
why is gastric lipase a weak enzyme
low pH
62
what is needed for B12 absorption
intrinsic factor
63
how is the stomach regulated
pacemaker cells
64
3 phases of stomach regulation
cephalic
gastric
intestinal
65
which phase of gastric fxn involves see, taste, smell, thought
cephalic
66
duration of cephalic phase
a few min
67
nerve pathway of cephalic phase of stomach regulation
hypothalamus → medulla → vagus n stimulation → submucosal and myenteric plexus → activates exocrine glands/increases motility
68
gastric and intestinal phase duration
hours
69
bolus enters stomach → baroreceptors and chemoreceptors induce NS → increased force of contraction and release of of secretions
gastric phase
70
what induces gastrin release
presence of protein in stomach
71
chyme enters SI → intestinal reflex opposes cephalic and gastric reflex via M.O
intestinal phase
72
hormones involved in intestinal phase of gastric fxn (3)
CCK
secretin
GIP
73
presence of chyme stimulates
CCK
secretin
74
in the intestinal phase, nerves signals to medulla \_\_
which __ force of contractions and secretions
decrease
reduces
75
in the intestinal phase, CCK reduces
and secretin reduces
force of contractions
secretions
76
pepsinogen is produced by \_\_
and activated by \_\_
chief cells
HCl (secreted by parietal)
77
the mucosa of the small intestine is arranged into
circular folds
78
circular folds are made of (2)
villi
microvilli
79
circular folds are same-same
plicae
80
the epithelium of intestinal villus is made of __ cells (2)
goblet
simple columnar epithelial cells w. microvilli
81
location of capillary network, lymphatic nodules, and lacteals of intestines
mucosa
82
lymph vessel, venule, and arterioles of intestines are located in the
submucosa
83
fxn of simple columnar epithelial cell w. microvili
absorbs nutrients
84
fxn of goblet cell
produces mucin
85
fxn of unicellular gland cell of intestines
syntheizes enteropeptidases
86
fxn of enteroendocrine cell of intestines
secretes hormones
87
specialized mucous-secreting glands of the SI that secrete a thick alkaline mucus in response to certain stimuli
brunner's glands
88
enzymes in the membranes of microvilli (5)
peptidase
sucrase, maltase, lactase
lipase
89
hormones secreted by the SI (5)
enterokinase
somatostatin
cholecystokinin (CCK)
secretin
90
fxn of enterokinase
converts trypsinogen to trypsin
91
fxn of somatostatin
inhibits acid secretion by stomach
92
what 2 hormones are involved in regulation of secretion of the liver/gallbladder/pancreas
cck
secretin
93
cck and secretin both secrete
enteroendocrine cells
94
cck is stimulated by (2)
fat in duodenum
presence of proteins/aa
95
secretin is stimulated by
chyme enters duodenum → lowers pH in duodenum
96
fxn's of cck (4)
inhibits stomach activity
gallbladder releases bile
pancreatic acini release digestive enzymes
hepato-pancreatic sphincter opens
97
fxn's of secretin (3)
inhibits stomach ac
98
pathway of bile
r/l hepatic ducts → common hepatic duct → bile duct → pancreatic duct → duodenal papilla
99
fold of the peritoneum that connects the liver to the diaphragm
falciform
100
the falciform continues inferiorly to form the __ ligament,
which originates from the \_\_
round
umbilical vein
101
digestive fxn's of liver (3)
fat emulsification (bile)
absorption of lipids
hydrophobic waste excretion
102
3 general fxn's of liver
metabolism
storage
synthesis
detox
103
what does the liver synthesize (2)
blood pro
cholesterol
104
deoxygenated nutrient rich blood from the digestive organs enters the \_\_
and mixes with oxygenated blood from the \_\_
in the \_\_
hepatic portal vein
aorta
sinusoid
105
after mixing in the sinusoid, nutrient rich blood enters the \_\_
and then travels to the \_\_
hepatic veins
inferior vena cava
106
left and right hepatic ducts merge to form
common hepatic duct
107
common hepatic and cystic ducts merge to form a
common bile duct
108
the main pancreatic duct merges with the common bile duct at the \_\_
which extends into the \_\_
hepatopancreatic ampulla
109
bile and pancreatic juices enter the duodenum at the \_\_\_
major duodenal papilla
110
layers of the gallbladder (4)
tunica
mucosa
muscularis
serosa
111
bile pathway from the gallbladder
bile canaliculi → bile ductules → hepatic ducts (r/l) → common hepatic duct → small intestine via hepatopancreatic sphincter
112
if not used, bile backs up via the \_\_
into the \_\_
bile duct
cystic duct
113
fxn of the gallbladder (2)
storage
concentration
114
98% of pancreatic tissue is made of \_\_
which has __ fxn
and secretes
\_\_
acini
exocrine
digestive enzymes
115
2% of the pancreas is made of \_\_
which has __ function
and secretes \_\_
islet cells
endocrine
hormones: insulin, glucagon
116
what digestive enzymes do the acinar cells of the pancreas secrete (4)
amylase
lipase
protease
nuclease
117
alpha cells of the pancreas secrete \_\_\_
beta cells secrete \_\_
alpha: glucagon
beta: insulin
118
steps in regulation of pancreatic secretion
1. acidic chyme enters duodenum
2. intestinal mucosa release secretin into bloodstream
3. secretin stimulates pancreas to secrete bicarbonate ions
4. pancreatic juice rich in bicarbonate ions passes down pancreatic ducts into duodenum
119
what hormones help regulate the release of pancreatic juice
secretin
cck
120
which hormone stimulates the pancreas to release pancreatic juice high in **bicarbonate ions**
secretin
121
what hormone stimulates the pancreas to release pancreatic juice high in **enzymes**
cck
122
why are several digestive enzymes secreted as zymogens
so that they only act in the lumen of the alimentary canal
123
what are zymogens
inactive substances converted to enzymes when activated by other enzymes
124
what is the site of contact digestion
brush border of SI
125
which of the following enzymes fxn at the lowest pH
a. salivary amylase
b. pancreatic amylase
c. pepsin
d. trypsin
e. dipeptidase
pepsin
126
fxn of large intestine (3)
absorption
compaction
storage
127
what does LI absorb
water
lytes
B vitamins
vitamin K
128
how does histology of LI differ from SI (4)
no plicae or villi
high # of goblet cells
high # of glands and lymph nodes
teniae coli
129
motility of LI involves (2)
haustral contraction
mass movement
130
haustral contraction produces __ waves daily
and is based on \_\_
and __ reflexes
3-4
gastrocolic and duodenal colic
131
tunics are same-same
histologic layers:
mucosa
submucosa
muscular layer
serous layer/serosa
132
what induces the defecation reflex
stretch in the rectum
133
where do hemorrhoids occur
rectal veins
134
steps in elimination
1. rectum content stimulates baroreceptors in rectum wall
2. sensory input initiated baroreceptors in rectum is relayed to spinal cord
3. motor output in parasympathetic axons is altered causing →
4. increased motor output to smooth m, rectum contraction (squeezes contents), decreased motor output (sphincter relaxation)
5. external anal sphincter relaxes → valsalva eliminates feces
135
conscious decision to defecate is controlled by
cerebral cortex
136
how do CHO enter hepatic portal system
via epithelial lining to blood capillaries in villi
137
CHO are stored as
glycogen
TG
138
enzymes involved in last step of disaccharides
brush border enzymes
139
brush border enzymes ___ (3)
break oligosaccharides in to \_\_
dexstrinase
glucoamylase
maltase
glucose molecules
140
proteins involved in protein digestion (4)
carboxypeptidase
trypsin
chymotrypsin
aminopeptidase
141
enzymes involved in protein digestion work on __ bonds
peptide
142
what activates trypsinogen into trypsin;
trypsin activates \_\_
enteropeptidases
other proteolytic enzymes
143
pancreatic proteolytic enzymes break proteins into (2)
peptides
aa
144
brush border enzymes break peptides into \_\_,
which are absorbed thru __ into the blood
single aa
epithelia
145
bile emulsify lipid droplets into
micelles
146
pancreatic lipase breaks TG into
monoglycerides
FFA
147
MG and FFA are absorbed thru \_\_
where they are packaged into \_\_,
and bile is \_\_
epithelia
chylomicrons
reabsorbed/recycled
148
monosaccharides (3)
glucose
fructose
galactose
149
non CHO components of CHO
glycerol
aa
150
non CHO components of CHO are converted into
glucose
151
protein digestive fxn's of liver (3)
deamination: conversion of NH2 → urea
transamination: aa converted from one form to another
form proteins from aa (including plasma proteins)
152
steps in lipid digestive by liver
1. lipogenesis: FA + glycerol → TG
2. lipolysis: FA released from TG
3. break down FA using acetyl CoA (beta oxidation)
4. acetyl CoA changed to ketone bodies → released into blood → transported to other cells → oxidized in respiratory pathways
153
acetyl CoA is changed to ketone bodies or
used in cholesterol synthesis
154
cholesterol is released into blood w. \_\_
or used to form \_\_
VLDL
bile salts
155
pancreatic __ break nucleic acid into
\_\_
nucleases
nucleotides
156
brush border enzymes including __ (2)
break nucleotides into __ (3)
which are absorbed into \_\_
phosphatases and nucleosidases
N-base, ribose, phosphate
blood capillaries
157
chemical digestion breaks \_\_
into \_\_
nucleic acids
nucleotides
158
gastric enzymes (2)
pepsin
gastric lipase
159
pancreatic enzymes (5)
pancreatic amylase
pancreatic lipase
trypsin
chymotrypsin
nucleases
160
intestinal enzymes (6)
peptidase
sucrase, maltase, lactase
intestinal lipase
enterokinase
161
the gastric pit is made of what type of
simple columnar epithelium
162
the gastric gland is made of
simple cuboidal epithelium
