Physio Quizzes Flashcards
(137 cards)
1
Q
APs in GI smooth muscle are stimulated when:
A
slow waves are depolarized above -40mV
2
Q
APs in the GI are caused by the influx of __
A
Calcium
3
Q
depolarization of the slow waves can result from (3 things)
A
local stretch (mechanoreceptors acting on enteric nerves), extrinsic nerves, peptides
4
Q
In the absence of extrinsic innervation to the gastrointestinal tract, motility and secretion would be stimulated by: (four things)
A
mechanoreceptors, chemoreceptors, osmoreceptors, hormones
5
Q
in the SI, peristalsis involves (relaxation/contraction) of the circular muscle proximal to the bolus of the chyme
A
contraction–produces aboral movement of the chyme
6
Q
the main/strongest contractions of the MMC (migrating myoelectric complex) are during phase (II/III)
A
phase III
7
Q
a series of contractions that sweep undigested fibers and bacteria into the colon
A
MMC
8
Q
the hormone ____ stimulates phase III MMC contractions
A
motilin
9
Q
the MMC occurs during (feeding/fasting/both)
A
fasting
10
Q
four functions of GI tract
A
secrete endocrine hormones, secrete digestive enzymes, absorb nutrients from chyme, store chyme
11
Q
a condition in which the LES fails to relax during swallowing
A
achalasia
12
Q
pressure tracing indicative of achalasia: (low, negative pressure/high, positive pressure)
A
high positive pressure, fails to decrease after swallowing
13
Q
subatmospheric pressure occur in the esophagus where?
A
where it passes through the chest cavity
14
Q
migrating motility complexes (MMC) occur about every __ minutes between meals
A
90 min
15
Q
MMCs are stimulated by which hormone
A
motilin
16
Q
an absence of MMCs causes an increase in what
A
intestinal bacteria
17
Q
MMCs (do/do not) have a direct effect on mass movements and swallowing
A
do not
18
Q
the autonomic nervous system controls gut motility by changing (slow wave frequency/spike potential frequency)
A
spike potential frequency
19
Q
slow waves in GI smooth muscle are caused by variations in calcium conduction in specialized pacemaker cells called
A
interstitial cells of Cajal
20
Q
the discharge frequency of the pacemaker cells and slow waves is (fixed/variable)
A
fixed
21
Q
the number of spike potentials associated with a given slow wave is (decreased/increased) by parasymp stimulation
A
increased (and decreased by symp stimulation)
22
Q
gastrin and secretin (have/do not have) significant effects on gut motility
A
do not have
23
Q
the (UES/orad stomach) undergoes receptive relaxation when a bolus of food is swallowed
A
orad stomach
24
Q
salivary secretion is controlled primarily by (symp/parasymp) NS
A
parasymp
25
when active, acetylcholine release (decreases/increases) salivary secretion and blood flow to the acini
increases
26
blocking cholinergic signaling (increases/decreases) salivary flow and blood flow to the acini
decreases
27
salivary ionic composition is dependent on
flow rates
28
when salivary flow rate decreases, Cl- content (increases/decreases)
decreases
29
when salivary flow rate decreases, K+ concentration (decreases/increases)
increases
30
anticholinergics (increase/decrease) mucus productions by salivary glands
decrease
31
parietal cell gastric acid secretion is regulated directly and indirectly by:
the vagus nerve
32
gastrin stimulates _____ cell acid secretion both directly and indirectly
parietal
33
There is potentiation between _____, gastrin, and acetylcholine so that the combined response is greater than the sum of individual responses
histamine
34
secretions entering the lumen of the stomach (four)
lipase, HCl, mucus, intrinsic factor
35
Gastric inhibitory peptide (GIP) is an endocrine hormone secreted from cells in the:
duodenum and jejunum
36
starch digestion is initiated by _____ in the _____
salivary alpha amylase in the mouth
37
pancreatic alpha amylase digests remaining starch into:
malto-oligosaccharides
38
intestinal brush border saccharides digest olidgosaccharides and disaccharides to:
monosaccharides
39
proton pump activity drives ___ ___ secretion and is the target for regulatory hormones, peptides, nerves
gastric acid secretion
40
the proenzyme pepsinogen is secreted mainly from:
gastric/oxyntic glands of the stomach
41
pepsinogen is the precursor of the enzyme
pepsin
42
which cells in the gastric glands secrete pepsinogen
peptic/chief cells
43
to be converted from pepsinogen to pepsin, pepsinogen must come in contact with
HCl or pepsin itself
44
pepsin is a proteolytic enzyme that digests collagen and other types of CT in ___ (type of food)
meats
45
the cephalic phase of gastric secretion accounts for about __% of the acid response to a meal and occurs (before/during/after) food enters the stomach
30%, before
46
cephalic phase of gastric secretion is stimulated by
seeing, smelling, chewing, anticipating food (mechanoreceptors in mouth, chemoreceptors, hypoglycemia)
47
cephalic phase of gastric secretion is mediated entirely by:
vagus nerve
48
an antigastrin antibody would (abolish/attenuate) cephalic phase
attenuate--because no effect on histamine and acetylcholine stimulation of acid secretion
49
atropine would (attenuate/abolish) cephalic phase by (stimulating/blocking) ACh receptors on parietal cells
attenuate
| blocking
50
atropine (does/does not) abolish ACh stimulation of gastrin secretion
does not
51
a histamine H2 blocker would (attenuate/stimulate/abolish) the cephalic phase of gastric secretion
attenuate
52
digestion of ____ is impaired in patients with achlorhydria (failure of HCl secretion by stomach)
protein
53
when stomach fails to secrete HCl
achlorhydria
54
how is achlorhydria diagnosed
when pH of gastric secretions fails to decrease below 4 after stimulation by pentagastrin
55
why is protein digestion impaired when HCl is not secreted
HCl is needed to convert pepsinogen to pepsin
56
pentagastrin administered through IV would lead to a less than normal increase in (gastric acid secretion/gastrin secretion)
gastric acid secretion
57
major anion in the pancreatic secretions
HCO3- (found in higher [ ] than in plasma)
58
[Cl-] is (higher/lower) in the pancreas than in the plasma
lower
59
pancreatic secretion is stimulated by the presence of _____ in the duodenum
fatty acids
60
(secretin/gastrin) stimulates pancreatic HCO3- secretion
secretin
61
(CCK/secretin) stimulates pancreatic enzyme secretion
CCK
62
pancreatic secretions are (hypotonic/isotonic)
isotonic
63
cystic fibrosis is caused by abnormal _____ ion transport on the apical surface of epithelial cells in exocrine gland tissues
chloride
64
the (gall bladder/liver bile) has higher bilirubin concentration
gall bladder
65
the primary function of CCK in a cholescintigaphy test is:
to contract the gall bladder
66
a structure with a small polymolecular aggregate containing bile salts, monoglycerides, and fatty acids as its major constituents
micelle
67
purpose of micelle
to speed absorption of fatty acids and monoglycerides by delivering its contents to the outer surface of the intestinal epithelial cell
68
(fatty acids and monoglycerides/conjugated bile salts) are absorbed chiefly by epithelial cells of duodenum and jejunum
fatty acids and monoglycerides
69
(fatty acids and monoglycerides/conjugated bile salts) are absorbed in the terminal ileum
conjugated bile salts
70
____ and ____ acids are produced in the small or large intestine from the primary bile acids or bile salts by bacterial action.
Deoxycholic and lithocholic (called secondary bile acids)
71
Cholic acid and chenodeoxycholic acid are conjugated in the liver with ____ and ____
taurine and glycine (cholic and chenodeoxycholic acids are primary bile acids)
72
(decreased/increased) fat absorption in the small intestine results from the deconjugation of bile salts by microorganisms
decreased
73
bacterial overgrowth in the small intestine can cause (increased/decreased) fat absorption
decreased
74
removal of the terminal ileum causes an (decreased/increased) synthesis of bile salts by the liver
increased
75
the gallbladder will (relax/contract) in response to emotional stimuli such as hostility, as well as in response to food in the mouth
contract
76
The concentration of sodium in gallbladder bile is approximately (half/twice) that in hepatic duct bile
twice
77
produced by duodenal cells and increase either the volume or the enzyme content of the exocrine secretion of the pancreas
secretin and CCK
78
converted to chymotrypsin by the action of trypsin
chymotrypsin
79
trypsinogen is secreted by the
pancreas
80
chymotrypsinogen is secreted by the pancreatic ____ cells
acinar
81
____ and ____ reduce polypeptides into smaller peptides
chymotrypsin and trypsin
82
insulin is necessary for entry of glucose into the tissues via (GLU4/GLUT1) transporters
GLU4
83
(GLU4/GLUT1) transporters are insulin-sensitive transporters present on most cell membranes and insertion of these transporters facilitates glucose entry
GLU4
84
what do these things stimulate? GLP-1, aa's, glucose insulinotropic peptide, fatty acids
insulin secretion
85
(GLUT1/GLUT2) transporters are prominent on the pancreas, small intestine , brain, and liver and facilitate entry of glucose into the cells.
GLUT2
86
In the β-cell of the pancreas, glucose metabolism (decreases/increases) ATP and reduces K+ (efflux/influx)
increases ATP
| reduces K efflux
87
reduced K+ efflux (hyperpolarizes/depolarizes) the beta cell in the pancreas, causing Ca influx and release of insulin
depolarizes
88
Insulin is a hypoglycemic hormone because it increases (glycogenolysis/GLUT4 transporters in adipose tissue and skeletal and cardiac muscle membranes)
GLUT4 transporters in adipose tissue and skeletal and cardiac muscle membranes
89
what is used as an index of the secretory capacity of the endocrine pancreas
C-peptide
90
what factor is responsible for the observation that an oral glucose load releases more insulin and is metabolized more rapidly than injected glucose
GLIP: glucose dependent insulinotropic peptide--strong stimulator of insulin release
91
somatostatin (stimulates/inhibits) insulin release
inhibits
92
amino acids (stimulate/inhibit) insulin release
stimulate
93
glucagon stimulates glycogenolysis in (liver/muscle/both)
liver only
94
cortisol (increases/decreases) gluconeogenesis
increases
95
cortisol (increases/decreases) glucose uptake in muscle
decreases
96
hypoglycemia (inhibits/stimulates) secretion of growth hormone
stimulates
97
hypoglycemia (inhibits/stimulates) secretion of epinephrine
stimulates
98
hypoglycemia (inhibits/stimulates) secretion of glucagon
stimulates
99
a high protein meal (stimulates/inhibits) insulin, glucagon, growth hormone
stimulates all three
100
which process in the SI does not cause Na to accumulate in enterocytes: (absorption of HCO3-/Na-K ATPase/aa absorption/galactose absorption/H+ antiport)
Na-K ATPase
101
specific site of absorption of Vit B12
distal ileum
102
deficiency of B12 leads to
pernicious anemia
103
which disease? flattening of intestinal villi decreases enzymatic digestion and reduces the area for absorption.
celiac sprue
104
there (is/is no) limitation to absorption posed by intracellular [B12]
is no--the concentration of B12 in enterocytes does not affect the absorption of Vit B12
105
Vit B12 binds with ______ on binding sites in the ileum
intrinsic factor
106
site of secretion of intrinsic factor: gastric (fundus/antrum)
fundus
107
cells that secrete intrinsic factor
parietal (also secete HCl)
108
where are these all absorbed: triglycerides, pyrimidines, Na, neutral aa's, glucose
upper third of small intestine (duodenum and jejunum)
109
(bile salts/triglycerides) are absorbed in the upper third of the SI
triglyercides--if bile salts were absorbed there, it would interfere with fat digestion
110
pancreozymin
CCK (same thing)
111
secretin causes pronounced increase in ______ secretions
pancreatic
112
cholera causes diarrhea because it increases __ (ion) secretory channels in ____ (cell type)
Cl- in crypt cells
113
enzymes capable of digesting (nucleic acids/proteins) are only secreted as inactive precursors
proteins
114
SGLT-1 mutation--treat with a special diet of (amylopectin/sucrose/fructose/glucose)
only fructose
115
congenital lack of (pepsinogen/enterokinase): hypoproteinemia, incapable of protein hydrolysis at neutral pH unless a small amount of trypsin is added
congenital lack of enterokinase
116
NPC1L1 knock out: abnormal (triglyceride/cholesterol/phospholipids)
cholesterol
117
main digestible carb consumed in human diet
starch
118
not normally found in abundance in portal blood: (triglycerides/aa's/glucose/short chain fatty acids)
triglycerides
119
after entering the epithelial cell, fatty acids and monoglycerides are taken up by the cell's ___ (organelle) where they are mainly used to form new triglycerides that are released in the form of chylomicrons from the base
SER
120
H2 is elevated in breath of people with _____ deficiency
lactase-- gut bacteria quickly switch over to lactose metabolism, which results in fermentation that produces copious amounts of gas
121
enzyme that activates one or more proteolytic enzymes: (trypsin/enterokinase/pepsin)
all three
122
CCK (increases/decreases) pancreatic enzyme secretion
increases
123
CF: __ (ion) channel defect
chloride
124
gall bladder has (higher/lower) [bilirubin] than liver
higher
125
what does CCK do to the gallbladder
makes it contract
126
a structure with a small polymolecular aggregate containing bile salts, monoglycerides, and fatty acids as its major constituents
micelle
127
brain center responsible for relaxing internal urethral sphincter and facilitating detrusor muscle contraction once voluntary relaxation of external sphincter has occurred
pontine micturition center
128
the pudendal nerve innervates the
external anal sphincter, which is skeletal muscle under voluntary control
129
severe hypoklaemia in a case of infant diarrhea due to (failure to absorb potassium in colon/excess secretion of K in colon)
excess secretion of K in colon
130
K secretion in the distal large intestine occurs through:
tight junctions
131
In infants, defecation often follows a meal. The cause of colonic contractions in this situation is
the gastrocolic reflex
132
the urge to defecate is caused by relaxation of:
the internal anal sphincter
133
mass movements cause (contraction of internal anal sphincter/rectal distension)
rectal distension
134
Hirschsprung disease: obstruction in which portion of the gut
sigmoid colon
135
The amount of flatus produced will (remain the same/more than double) if one switches from an average diet to one in which 25% of the caloric intake is pork and beans
more than double
136
symptoms associated with constipation are attributable to:
distension of the rectum
137
Approximately __% of the dry weight of the feces is bacteria
10%
