GI Flashcards
(153 cards)
1
Q
What is the role of the inner circular muscle of the GIT?
A
decreases diameter of lumen
2
Q
What muscle shortens the segment of GIT?
A
Outer longitudinal layer
3
Q
What layer of the GI muscle controls GI secretions?
A
Muscularis Muscle
4
Q
What is the extrinsic, parasympathetic nerve supplying the esophagus and upper large intestine
A
vagus nerve
5
Q
What is the role of the intrinsic innervation in the GIT?
A
coordinates and relays info from ANS to GIT
6
Q
What is intrinsic innervation between the submucosa and inner circular muscle layer?
A
Meissner Plexus
Remember: Miss Sub Secs
Meissner = Submucosa = Secretion
7
Q
What is the intrinsic innervation between inner circular and outer longitudinal muscle layer of the GIT
A
Auerbach Plexus
Remember, My Back
Myenteric = Aurbach
8
Q
Which intrinsic innervation plays a role in GI secretion?
A
Meissner = Submucosal plexus = Secretions
9
Q
What intrinsic innervation plays a role in GIT motility?
A
Myenteric = Auerbach = Motility
Remember, My Bach Moves
10
Q
What layer is not seen in the esophagus
A
serosa
11
Q
What is the strongest layer of the esophagus?
A
submucosa
12
Q
What are the 3 layers of the stomach?
A
inner oblique, middle circular, outer longitudinal
13
Q
Myenteric plexus is inhibitory in which part of the GIT?
A
- Pyloric Sphincter
2. Ileocecal Valve
14
Q
[GI Hormone]
Its release is triggered by proteins and amino acids
A
Gastrin
15
Q
What amino acids trigger gastrin release
A
MWF
16
Q
G cells secreting gastrin is located in which part of the stomach?
A
antrum
17
Q
What are the actions of gastrin?
A
- Stimulate parietal cells in fundus to secrete HCl
2. Growth of gastric mucosa
18
Q
[GI Hormone]
What hormone is triggered by fatty acids
A
CCK
19
Q
What cell secretes CCK?
A
I cells
20
Q
Which part of the GIT tract where I cells secrete CCK
A
duodenum
21
Q
What are the actions of CCK
A
- GB contraction, sphincter of oddi relaxation
- Increase GET
- Increase pancreatic enzyme secretion
22
Q
What triggers the release of secretin?
A
- Presence of H+ in the duodenum
2. Fatty acids in duodenum
23
Q
What cells secrete the hormone secretin?
A
S cell
24
Q
S cells that secrete secretin is located in which part of the GIT?
A
duodenum
25
What are the actions of your secretin?
1. Inhibit HCl secretion
| 2. Increases biliary and pancreatic HCO3
26
What GI hormone is not affected by the hormine secretin?
pancreatic enzyme
27
The release of GIP is triggered by ____
increase in oral glucose
28
What cell in the GIT secrete the hormone GIP
K cells
29
What is the action of your GIP?
1. Inhibit gastric emptying above normal physiologic levels
30
What triggers the secretion of motilin
Fasting
31
What cell in the GIT secrete motilin?
M cells
32
M cells that secrete motilin is seen in which part of the GIT?
duodenum and jejunum
33
What are the actions of your motilin?
1. Activate interdigestive/MMC
| 2. Acts only on the stomach and small intestine
34
What hormone opposes the release of HCl?
Secretin
35
What is the net effect of the release of GIP
increased insulin
36
What cells in the GIT secrete GLP-1?
L cells of the small intestin
37
What GI hormone is stimulated by CHO rich meal?
GLP
38
What are examples of you incretin?
1. GIP
2. GLP
3. Glucagon
39
What are examples of your GI paracrine hormones?
1. Somatostatin
| 2. Histamin
40
What hormone inhibits the release of ALL GI hormones
Somatostatin
41
What cells in the gastric mucosa secrete histamine?
mast cell
42
What is the action of histamine int he GIT?
1. Increase H+ secretion
2. Inhibits insulin
3. Inhibit glucagon
43
What are examples of you GIT neurocrines?
1. VIP
2. Enkephalin
3. GRP (bombesin)
44
VIP is a neurocrine hormone of the GIT that relaxes what structures int eh GIT?
1. Relaxes LES
2. Orad stomach
3. Pyloric sphincter
4. Ileocecal valve
Ultimate muscle relaxant
45
What is the role of VIP in HCO3 and H+?
1. Stimulates HCO3 secretion
| 2. Inhibits gastric H secretion
46
what hormone is involved in your pancreatic cholera?
VIP
47
What neurocrine hormone inhibits the secretion of fluids and electrolytes in the GIT?
Enkephalins
48
What are the types of enkephalins seen in the GIT?
1. met enkephalin
| 2. Leu enkephalin
49
What is the action of enkephalin in the GIT sphincters?
1. Contracts LES
2. Contracts Pyloric sphincter
3. Contracts Ileocecal valve
50
What neurocrin stimulates the release of gastrin from G cells?
GRP (Bombesin)
51
[Brain part]
inhibits appetite, found in the ventromedial hypotalamus
satiety center
52
[Brain part]
the appetite/hunger center is located in which part of the brain?
Lateral hypothalamic
53
The arcuate nucleus is important in GIT. It sends signals to ____
Satiety and hunger center
54
Which neuron releases POMC to decrease the appetite?
Anorexigenic neurons
55
What is released by your orexigenic neurons to increase appetite?
Neuropeptide Y
56
What hormones stimulate anorexigenic neurons and inhibits orexigenic neurons?
1. Leptin
2. Insulin
3. GLP-1
57
What hormone inhibits anorexigenic neurons that is secreted by gastric cells?
ghrelin
58
What inhibits the secretion of ghrelin?
Peptide YY
59
Which part of the GIT tract is not made up of unitary smooth muscle?
1. Pharynx
2. Upper 1/3 of the esophagus
3. External anal sphincter
60
Tonic contractions of the GIT can be seen in _____
1. Upper region of the stomach
2. Lower esophagus
3. Ileocecal
5. Internal anal sphincter
61
Tonic contractions of the GIT is due to?
Subthreshold slow waves
62
Phasic contractions are seen in which part of the GIT?
1. Esophagus
2. Gastric antrum
3. Small intestine
63
This causes the phasic contraction of the GIT?
spike potential
64
[Electrical activity of GI smooth muscle]
determines the pattern of contraction; due to the interstitial cells of cajal; slow, oscillating membrane potentials
Slow waves
not true action potentials
brings you closer to threshold
65
[Electrical activity of GI smooth muscle]
slow waves has a slowest frequency in which part of the GIT?
Stomach
66
[Electrical activity of GI smooth muscle]
Slow wave is fastest in which part of the GIT?
Duodenum
67
[Electrical activity of GI smooth muscle]
What causes the depolarization of spike potentials?
Calcium infux
68
What is the pacemaker of the GIT?
Interstitial cell of Cajal
69
What is the most common stimulus fo GI peristalis?
Distention
70
How many hours will it take to transfer the material from the pylorus to ileocecal valve?
3-5 hours
71
How many hours will it take to transfer digested material from ileocecal valve to colin?
8 to 15 days
72
What nerve is utilized during swallowing?
CN IX, X
in the medulla
73
What are the events during the pharyngeal phase?
1. Soft palate pulled upward (closes the nasopharynx]
2. glottis covered prevents aspiration
3. Upper esophageal sphincter relaxes
74
What triggers the secondary peristalsis?
Gastric acid reflux to the esophagus
75
What enzyme is deficient in achalasia?
Yep! Enzyme.
NO synthase that makes NO.
Deficient myenteric plexus, deficient neurocrine release (NO, VIP), decreased receptive relaxation
76
What hormones facilitate receptive relaxation of the lower esophagus?
NO, VIP
77
What hormones facilitate receptive relaxation of Orad stomach?
1. VIP
| 2. CCK
78
What nerve stimulates gastric contractions?
Parasympathetic via Vagus Nerve
79
What is the capacity of the stomach?
1.5L
80
Motilin stimulates gastric contractions every ___
90 minutes
motilin = motility
81
What facilitates gastric emptyong?
1. isotonic contents
| 2. chyme formation
82
What inhibits gastric emptying?
1. Fat (via CCK)
| 2. H+ in the duodenum
83
What initiates the decreased gastric emptying time?
hyperosmolality of duodenal contents
84
What increases the rate of gastric emptying time?
Intragastric volume
If madami content, fat, acid sa small intestine, mag stop ang gastric emptying
85
What type of contraction allows mixing of chyme with pancreatic enzyme?
Segmentation contraction
86
In peristaltic contractions, in order to propel the bolus forward, the longitudinal muscles should ___
1. Contract behind the bolus
| 2. relax infront of bolus
87
What prevents reflux of chyme from the cecum to the ileum?
Ileocecal valve
88
What is the primary role of proximal colon?
absorption of water
89
What is the primary role of your distal colon?
storage of feces
90
The movement of colonic contents called mass movement occurs how many times a day?
1-3x per days
91
Urge to defecate is felt when the rectum is filled by how much? (percent)
25%
Internal anal sphincter is involuntary
92
What relaxes the internal anal sphincter?
Rectal contents = rectosphincteric reflex
93
In order for defecation to occur, you external and internal anal sphincters should
Relax.
Normally, internal anal sphincter is contracted, you external anal sphincter is contracted
94
___ reflex refers to when food in the stomach increases peristalsis in the ileum, and relaxation of the ileocecal sphincter
Gastroileal reflex
95
___ reflex refers to food in the stomach increases peristalsis in the colon
Gastrocolic reflex
96
What mediates the gastrocolic reflex?
1. Parasympathetic NS
2. CCK
3. Gastrin
97
What causes the normal bowel movements in newborn?
Gastrocolic reflex
98
Reverse peristalsis, like in vomiting, begins in which part of the GIT?
Small intestine
Vomiting center: Medulla
99
Which part of the brain is triggered by emetics, radiation and vestibular stimulation
Chemoreceptor Trigger Zone (area postrema)
100
___ refers to incomplete vomiting through a closed upper esophageal sphincter
Retching
101
[GI Juices]
most basic
1. Brunners gland secretions
| 2. Pancreatic Juice
102
[GI Juices]
how many mL of HCl is secreted per day?
1.5L
103
What organs produce saliva
1. Parotid
2. Submandibular
3. Sublingual
104
What electrolytes are high in the saliva?
High in K and HCO3
Low in Na, Cl
hypotonic
105
What digestive enzymes are present in the saliva?
1. Amylase
| 2. Lingual lipase
106
[Effect to salivation]
parasympathetic stimulation
Increases salivation
107
[Effect to salivation]
sympathetic salivation
Increases salivation
High flow rates, saliva has high Na, Cl low K, HCO3
108
What electrolytes are high in initial saliva?
Na, Cl
the final saliva is High in K, HCO3
109
What hormone plays a role in reabsorbing Na in the ductal cells making the final saliva low in K and HCO3?
Aldosterone
110
Relative to plasma, salava is ___ (hyper/hypotonic)
Hypotonic
111
Oxyntic glands is located in which part of the stomach?
Body
Contains:
1. Mucus neck cells
2. Parietal cells
3. Chief Cells
112
Pyloric glands is located in which part of the stomach?
Antrum
Contains:
1. G cells
2. Mucus cells
113
What cells secrete mucus and HCO3?
1. Mucus cells
| 2. Mucus neck cells
114
What cells secrete HCl and IF?
Parietal or Oxyntic Cells
115
What cells secrete serotonin in teh GIT?
Enterochromaffin cells
116
What cells secrete histamine in the GIT?
Enterochromaffin-like cells
117
What cells secrete pepsinogen?
chief/peptic cells
118
Intrinsic factor is secreted in which part of the stomach?
Gastric Fundus
119
What stimulates HCl Secretion?
1. Histamine on H2 receptors
2. Ach on M3 receptors
3. Gastrin on CCKb receptors
120
What increases the basal acid output in the stomach?
Alkalinize the antrum
121
What inhibits HCl secretion?
1. Low pH (<3)
2. Somatostatin
3. Prostaglanding
122
What drug class inhibits both gastrin and acetylcholine mediated acid secretion?
H2 blockers
123
What hormone is high in Zollinger-Ellison Syndrome?
Gastrin = gastrinoma
resulting to high HCl
124
What is the tonicity of your pancreatic secretions?
Isotonic
contains high HCO3 to neutralize acids
125
What hormones stimulate the release of pancreatic enzymes?
1. Secretin
2. CCK
3. Acetylcholine
126
What are the effects of pancreatectomy?
1. Loss of exocrine pancreatic secretions
| 2. Loss of insulin secretion
127
What is the most common component of bile?
water
128
What is the active component of bile?
Bile acid
129
What are your primary bile acids?
1. Cholic Acids
| 2. Chenodeoxycholic acid
130
What are your secondary bile acids?
1. Deoxycholic acids
| 2. Lithocholic acids
131
What is added to you secondary bile acids to make bile salts?
1. Taurine
| 2. Glycine
132
What causes GB contraction?
1. CCK
| 2. Ach
133
What causes sphincter of Oddi Relaxation?
1. CCK
134
The release of bile is characterized as ______
pulsatile spurts
135
What will be the effect of surgical resection of ileum?
1. Increased water content of feces
136
What transporter is used to transport glucose and galactose from the lumen of the SI to the cell?
SGLT1 (secondary active transporter)
137
What transporter is used to transport fructose from the lumen of the SI to the cell?
GLUT-5
FRUIT = 5 letters = glut 5
138
What is the transporter of monosaccharides from the cell to the basolateral side?
GLUT 2
139
What are the brush border enzymes that is required for assimilation of protein?
Enterokinase/Enteropeptidase
140
What enzyme cleaves the C terminus of a polypeptide?
Exopeptidase = Ends/C terminal
141
What are the essential pancreatic proteases?
1. Trypsin
2. Chymotrypsin
3. Elastase
4. Carboxypeptidase A and B
142
What facilitates the absorption of your free amino acids in the luminal side?
Na-aa symport
143
What transports AA from the cell to the basolateral side?
Facilitated diffusion
144
Between dipeptides and free amino acids, which is absorbed faster?
Dipeptides
and tripeptides too
145
Lipids enter the intestinal cell via?
micelles
146
Lipids leave the cell via?
chylomicrons
147
What enzyme is inactivated by gastrinoma
pancreatic lipase
Gastrinoma = High gastrin = low gastric pH
148
Short chain fatty acids absorption almost exclusively happens in which part of the GIT?
colon
149
Vitamin B 12 is absorbed in which part of the GIT?
ileum
150
Iron and Vitamin C is absorbed in which part of the GIT?
Duodenum
151
Fat, proteins, carbohydrates and water are absorbed in the ___
jejunum
152
Vitamin ADEK are absorbed in the
ileum
153
IF-B12 complex and bile salts are absorbed in teh
ileum
