Test 4: Gastrointestinal Flashcards
(146 cards)
1
Q
Four major functions of the GI tract
A
(1) motility, (2) secretion (3) digestion, (4) absorption of nutrients, electrolytes, and water
2
Q
Outer plexus lying between the longitudinal and circular muscle layers
A
Auerbach’s plexus/myenteric plexus
3
Q
Inner plexus that lies in the submucosa that controls gastrointestinal secretion and local blood flow
A
Meisner’s/submucosal plexus
4
Q
[Intrinisic/extrinsic] innervation connects the myenteric and submucosal plexus’
A
extrinsic innervation connects the myenteric & submucosal plexus
5
Q
[Afferent/efferent signal] sends signal from brain to the body
A
afferent signal
6
Q
[Afferent/efferent] sends signal from the body to the brain
A
efferent signal
7
Q
Bacteria most common in large intestine
A
commensal bacteria
8
Q
2 functions of bacteria in intestines
A
(1) several metabolic functions not accomplished by GI enzymes, (2) provide protection against infection from pathogenic microorganisms
9
Q
Immune system of the intestines
A
Innate and adaptive immunity
10
Q
Location of most lymphocytes
A
In wall of intestines (NOT circulating in blood)
11
Q
Layers of GI wall from exterior to interior
A
Serosa/adventita > muscularis externia > submucosa > mucosa
12
Q
Layers of mucosa from exterior to interior
A
muscularis mucosae > lamina propria > epithelium
13
Q
Organ of GI tract that has the thickest muscularis mucosae
A
in the esophagus
14
Q
Layer of GI wall that allows for peristaltic movements
A
submucosa
15
Q
4 structures within submucosa (NOT LAYERS)
A
(1) collagen, (2) elastin, (3) glands, (4) blood vessels
16
Q
Layer of GI wall that controls the extent of intestinal villi
A
submucosa
17
Q
2 layers of muscularis externa from exterior to interior
A
longitudinal layer > circular layer
18
Q
Area where muscularis is thickest (with 3 layers)
A
In stomach
19
Q
Longitudinal muscle layered into longitudinal bands in the colon
A
taenia coli
20
Q
Result of circular muscle contraction on GI tract
A
Decrease diameter of lumen
21
Q
Result of longitdunal muscle contraction on GI tract
A
Shortening of a segment of tract
22
Q
Location of Auerbach’s plexus/myenteric plexus
A
Between circular and longitudinal muscle
23
Q
[Sympathetic/parasympathethic] of nervous tissue in Auerbach’s plexus
A
parasympathetic
24
Q
Component that allows low-resistance movement of ions from one muscle cell to the next
A
gap junctions
25
Ordinary fibrous connective tissue arranged around an organ and is attached to surrounding tissue
adventitia
26
Enzyme that chemically digests starches in the mouth but inactivated in stomach
salivary amylase
27
Enzyme released in the mouth but that digests fats in the stomach
lingual lipase
28
Cranial nerve responsible for muscles of chewing
5. Trigeminal
29
Non-digestible component that chewing breaks down
cellulose
30
Muscle type in the upper third of the esophagus
Voluntary, striated muscle
31
Nerve that innervates esophagus
Vagus n
32
The sphincter between esophagus and stomach
lower esophageal sphincter (psuedo-sphincter)
33
Structure that esophagus passes through at the lower esophageal sphincter
diaphragm
34
Length of esophagus in cm
30 cm
35
Portion of the esophagus that sits retroperitoneally
Distal 2/3
36
Histology of esophagus
non-keratinized stratified squamous epithelium (like skin, so it can take a beating)
37
Site of anastomosis between the esophageal branch of the left gastric a. and the esophageal a. (connects portal system to systemic circulation)
distal esophagus
38
Another word for heartburn
pyrosis
39
What is "food" called in the esophagus
bolus
40
What is "food" called in the stomach
chyme
41
4 portions of stomach from superior to inferior
cardia > fundus > body > antrum
42
Portion of stomach that overlaps with the lower esophageal sphincter
cardia
43
Hormone that does the opposite function of CCK and secretin
somatostatin - prevents gastric secretions and motility
44
Histology of stomach
columnar epithelium tissue
45
Layer of GI wall that contains gastric pits
gastric mucosa
46
Area of stomach that serves as a secretory region
fundus
47
Area of stomach that has extensive motility patterns
antrum
48
Cells that produce mucus that lines the stomach to protect from HCl
mucous cells
49
Cells that produce pepsinogen
chief cells
50
Cells that produce HCl and intrinsic factor
parietal cells
51
Cells that produce gastrin in the stomach
enteroendocrine cells
52
Nutrient broke down by pepsin
protein
53
Nutrient broken down by gastric lipase
Fat
54
Component necessary for the absorption of B12
intrinsic factor
55
Two factors that cause pernicious anemia
(1) autoimmune destruction of parietal cells, leading to a decrease in Hcl and IF, (2) autoimmune destruction of IF only
56
Materials absorbed in stomach
water, meds, alcohol, some minerals
57
Components that break down protein in the stomach
HCl, pepsin
58
Chemicals that break down triglyceride in the stomach
gastric, pancreatic, salivary lipase
59
Chemical that breaks down starch in stomach
salivary and pancreatic amylase
| salivary amylase inactivated in stomach
60
Mineral that HCl "preps"
iron
61
Mineral that intrinsic factor "preps"
B12
62
Process that ensures the stomach pressure does not increase significantly as it expands
receptive relaxation
63
Condition where the stomach cannot empty itself of food in a normal fashion (not due to a mechanical obstruction)
gastroparesis
64
Hormone that stimulates motility and gastric acid release
gastrin
65
Hormone that stimulates gall bladder contraction and pancreatic secretions
CCK
66
Hormone that stimulates pancreas juice and enzyme secretion and inhibits gastrointestinal motility
secretin
67
Order of sections of small intestine
duodenum > jejunum > ilium
68
Two structures that empty into the duodenum through the sphincter of Ode
Bile duct, pancreatic duct
69
Surface area of small intestines
~300m^2
70
Area of small intestine that most nutrients are absorbed
jejunum
71
3 components of duodenal cluster unit
(1) pancreas, (2) biliary, (3) proximal duodenum
72
Gland in duodenal mucosa that secretes mucus to neutralize acidic content (with HCO3-)
Brunner's gland
73
Large circular folds of mucosa that protrude into the lumen
Folds of Kerckring
74
Location of microvilli on cells
apical surface of villus epithelial cells
75
Portion of small intestine with fewer folds and shorter, sparser villi with less nutrient absorption
ileum
76
B-cells stimulated to differentiate into IgA-secreting plasma cells
Peyer's patches
77
The more distended the cecum is, the more intense the ileocecal valve contracts and the more inhibited the peristaltic movement becomes
ileocecal feedback
78
Order of structures of large intestine
cecum > ascending colon > transverse colon > descending colon > sigmoid colon > rectum > anal canal
79
Period of time that colonic motility increases significantly
after feeding
80
Primary motility function in large intestine
reservoir
81
[Small/large] intestines that do not contain villi
large intestines
82
Portion of mucosa that contains tubular glands and is responsible for mucus secretion
crypts
83
Function of motility that mixes food in the GI tract by moving food mass back and forth; involves contraction and relaxation of circular muscles
segmentation
84
Function of motility that consists of a series of wavelike rhythmic contractions/relaxation of circular and longitudinal muscles to propel food through GI tract
peristalsis
85
Nervous system that inhibits gastrin, gastric secretions, peristalsis and digestion
sympathetic nervous system
86
Nervous system that allows gastric secretions and promotes normal, relaxed digestion
parasympathetic nervous sytem
87
2 basic patterns of electrical activity across membranes of smooth muscle cells
(1) slow waves, (2) spike potentials
88
Type of contraction that includes tone (muscle) contraction like in sphincters
tonic contraction
89
Extrinsic nervous system component of the autonomic nervous sytem
sympathetic and parasympathetic innervation of GI tract
90
Intrinisic components of autonomic nervous system
Enteric Nervous system within GI wall
91
2 areas that intrinsic innervation receives input from
(1) parasympathetic and sympathetic nervous system, (2) mechanoreceptors and chemoreceptors in mucosa
92
Fluctuation in membrane potential in smooth muscle of GI tract
Between -65 mV and -45 mV
93
Exceptions of basic electrical rhythm (2)
esophagus and proximal portion of the stomach
94
Location of interstitial cells of Cajal in stomach/small intestine
Between circular muscle and myenteric plexus
95
Location of interstitial cells of Cajal in colon
In submucosal border of circular muscle layer
96
Ion in charge of depolarizing spike potential
Ca2+
97
Ion in charge of repolarizing spike potential
K+
98
Factors that affect basic electrical rhythm/spike potentials (2)
(1) polypeptides, (2) neurotransmitters
99
Chemical that increases the number of spikes and tension of smooth muscle
acetylcholine
100
Chemical that decreases the number of spike potentials and smooth muscle tension
epinephrine
101
3 factors that stimulation spike potential
(1) stretch, (2) acetylcholine, (2) parasympathetics
102
2 factors that stimulates hyperpolarization (slowing function)
(1) norephinephrine, (2) sympathetics
103
2 roles of "slow waves"/migrating motor complex
(1) flush remaining food and bacteria into large intestine, (2) to tell you that you're hungry
104
Area of GI tract that experiences MMC
stomach to SI
105
Hormone that initiates migrating motor complexes
motilin
106
Time interval of MMC
every 90 minutes
107
Components that increase during MMC
(1) gastric secretion, (2) bile flow, (3) pancreatic secretion
108
Process that consists of rhythmic contractions and relaxation involving circular and longitudinal muscle
peristalsis
109
Process that mixes food in the GI tract by moving food mass back and forth
segmentation
110
Involuntary stages of swallowing
pharyngeal and esophageal stage
111
The process that precedes peristalsis and is transmitted through myenteric inhibitory neurons in the stomach
receptive adaptation
112
Parasympathetic innervation of stomach
vagus n
113
Sympathetic innervation of stomach
splanchnic n
114
Time required for passage of chyme from pylorus to ileocecal valve
3 to 5 hours
115
Hormones that excite peristalsis
gastrin, CCK, insulin, motilin, serotonin
116
Hormones that inhibit peristalsis
secretin, glucagon
117
2 functions of colon
(1) absorption of water and electrolyes from chyme to solid feces, (2) storage of fecal matter
118
Organ that synethesizes and sends bile to gallbladder
liver
119
75% of the liver's blood supply is [arteriole/venous] blood
venous
120
distensible vascular cheannels lined with highly fenestrated endotheilia cells and bounded by hepatocytes
sinusoids
121
facial amphipathic
contain both non-polar (non polar) and polar (hydrophilic) faces
122
Hormone secreted in response to high acid in the duodenum
secretin
123
Product that must be eliminated in hemoglobin
heme
124
Roles of liver
(1) removal of ammonia, (2) synthesis of non-essential amino acids, (3) synthesize albumin
125
Endocrine function of pancreas
produce hormones
126
Exocrine function of pancreas
produce digestive enzymes
127
Beta-islet endocrine cells of the pancreas; secrete insulin, glucagon & several other hormones cell
Islets of Langerhans
128
2 Exocrine cells of the pancreas
acinar cells, centroacinar cells
129
Amount of isotonic aqueous secretions, secretions in the duodenum per day
1 L/day
130
Ions involved in a reciprocal relationship to maintain anionic concentration
HCO3- and Cl-
131
Protein associated with B12
R-protein
132
Inactive pancreatic proteases that are packaged
trypsinogen and chymotrypsinogen
133
Enzyme that activates trypsinogen
enterokinase
134
Cells responsible for the final digestion of peptides into mono form
peptidases on the surface of small intestinal epithelial cells
135
Enzyme that digests lipase into 2-monoglyceride and 2 free fatty acids
pancreatic lipase
136
Nerve that innervates the pancreas
vagus n
137
Hormone synthesized & secreted by enteric endocrine cells stimulated by presence of partialy digested proteins and fats in SI; stimulates gallbladder
cholecystokinin (CCK)
138
Hormone that is a product of endocrinocytes, secreted in response to acid in the duodenum, stimultaes duct cells to secrete water and bicarbonate
secretin
139
Hormone secreted by stomach in response to gastric distention and irritation; stimulates parietal cells & acinar cells to secrete digestive enzymes
gastrin
140
Secretory section of the stomach
fundus
141
Mixing, grinding section of the stomach
antrum
142
Cells in stomach that secrete mucus to protect from HCl
mucous cells
143
Lingual amylase and salivary lipase production will [increase/decrease] with age
decrease
144
Cells in the crypts of Lyberkum that test lumen
paneth cells
145
All asepcts of RBC are recycled exceped heme
145
All aspects of the RBC are recycled except _______
heme
