Gastrointestinal I Flashcards
1
Q
How long is the GI tract in a cadaver?
A
30 feet
2
Q
How long is the living GI tract?
A
around 15 feet
3
Q
Divisions of the small intestine:
A
Duodenum
Jejunum
Ileum
4
Q
Divisions of the Large Intestine:
A
Cecum Ascending Transverse Descending Sigmoid
5
Q
4 functions of the GI tract:
A
Motility
Secretion
Digestion
Absorption
6
Q
What are the constant low levels of contractions in the GI tract know as?
A
Tone
7
Q
What is the purpose of tone?
A
Maintain steady pressure
8
Q
What are the 3 types of motility?
A
Propulsive (peristalsis)
Segmentation (mixing)
Tonic contractions (sphincters/valves)
9
Q
2 functions of Segmentation?
A
Mechanical digestion
Facilitate absorption
10
Q
6 sphincters in the GI tract:
A
UES - Upper Espophageal Sphincter LES - Lower Esophageal Sphincter Pyloric Ileocecal Internal Anal External Anal
11
Q
What regulates the movement of contents of the common bile duct into the duodenum?
A
Sphincter of Oddi
12
Q
Where are the voluntary areas of control in the GI tract?
A
UES
External Anal Sphincter
*the ends
13
Q
What do the voluntary control areas in the GI tract have in common?
A
Skeletal muscle
instead of smooth
14
Q
How much saliva and gastric juice are produced daily?
A
- 5 L saliva
2. 5 L gastric juice
15
Q
How much bile and pancreatic juice are produced daily?
A
- 5 L bile
1. 5 L pancreatic
16
Q
How much intestinal secretion and mucus are produced daily?
A
- 0 L intestinal
2. 0 L mucus
17
Q
Most chemical digestion takes place via…
A
Hydrolysis
18
Q
Where are the brush border enzymes?
A
Plasma membrane of enterocytes
19
Q
How much fluid enters into or is secreted into the lumen of the intestine every day?
How much ends up in the stool?
A
9.0 L
100 mL
20
Q
Where to the 4 basic quadrants intersect?
A
Belly button
21
Q
What are the 9 Abdominal-Pelvic regions?
A
Rt and Lt Hypochondirac Epigastric Rt and Lt Lumbar Umbilical Rt and Lt Inguinal Pubic
22
Q
What layer covers the external surfaces of most digestive organs?
What is it continuous with?
A
Visceral peritoneum
Parietal peritoneum
23
Q
What lies between the visceral and parietal peritoneum?
A
Peritoneal Cavity
*with peritoneal fluid
lubricates
24
Q
What is inflammation of the peritoneum?
A
Peritonitis
25
What is the condition of accumulated peritoneal fluid called?
Ascites
26
What is a large fold of peritoneum in the abdominal cavity?
Greater Omentum
27
What is the greater omentum attached to?
Transverse colon
28
What anchors the small intestine to the posterior abdominal wall?
Mesentery
29
T/F
| The contents within the lumen are technically outside the body
True
30
What condition penetrates the gastric mucosal barrier?
Peptic Ulcer Disease (PUD)
31
What is obstructed in Acute Pancreatitis?
Main pancreatic duct
(causing rupture)
*damages pancreas, duodenum
32
What can cause peritonitis via bacterial invasion?
Ruptured appendix
33
What are the 4 major layers of the GI tract wall?
Mucosa
Submucosa
Muscularis Externa
Serosa
34
What delineates the Mucosa and Submucosa?
Muscularis mucosae
35
What is the self-induced electrical activity in the digestive smooth muscle called?
(3 things)
Slow-wave potential
Basal Electrical rhythm (BER)
Pacemaker potential
36
What are 2 terms for the submucosal and myenteric plexuses in the gut?
Intrinsic Nerve Plexuses
Enteric Nervous System
*sensory, motor, exocrine, endocrine, etc.
37
What is the parasympathetic innervation for the esophagus, stomach, small intestine, and ascending colon?
(upper GI tract)
Vagus
38
The mixed vagus nerves innervating GI tract are what percentage afferent and efferent?
Afferent: 75%
Efferent: 25%
39
What 4 GI tract structures does the Vagus nerve innervate parasympathetically?
Esophagus
Stomach
Small Intestine
Ascending colon
40
What is the parasympathetic innervation for the lower GI tract?
(transverse, descending, sigmoid colons and anal canal)
From where are they derived?
Pelvic splanchnic nerves
S2, S3, S4
41
The majority of parasympathetic nerves to the GI are ____.
| Some are _____.
Cholinergic
| Peptidergic
42
Name 4 peptidergic molecules.
VIP
Enkephalins
Neuropeptide Y
Substance P
43
What are the 3 divisions of Adrenergic (sympathetic) ganglia that serve the GI tract?
Celiac
Superior mesenteric
Inferior mesenteric
44
What percentage of Adrenergic nerves to the GI tract are afferent and efferent?
50/50
45
T/F
Autonomic nerves influence GI tract altering nerve activity, altering hormone secretion, and innervating smooth muscle and glands
True
46
What secretes hormones in the GI tract?
Endocrine cells
47
What condition is marked by no salivary production and increased caries?
Xerostomia
48
What autoimmune disease strikes salivary glands?
Sjogren's Syndrome
* most common cause of xerostomia
* *mostly women
49
Name 4 diseases that can cause xerostomia.
Sjogren's
HIV
Diabetes
Parkinsons
50
What receptors mediate normal salivary function?
M3
| muscarinic
51
What 3 components make up a salivary gland?
Acinus
Intercalated duct
Striated duct
52
What surrounds each acinus in the salivary gland?
| Function?
Myoepithelial cells
Contraction and release of saliva
53
What are the 3 categories of salivary acinii?
Serous
Mucous
Mixed
54
What percentage of total saliva doe each gland produce?
Submandibular - 71%
Parotid - 25%
Sublingual - 3-4%
55
What type of secretions do each of the salivary glands produce?
Parotid - serous
Submandibular - mixed
Sublingual - mucous
56
What do the salivary glands look like under a microscope?
Parotid - mostly dark (lack of mucous)
Submandibular - mixed dark and light
Sublingual - mostly white
57
What ducts drain the salivary glands?
Parotid - Stenson's
Submandibular - Wharton's
Sublingual - Ducts of Rivinus
58
What are the 3 most important salivary proteins?
Alpha-amylase
Lingual Lipase
Mucins
59
What does salivary alpha-amylase cleave?
What deactivates?
Internal Alpha1,4
(no terminals or Alpha 1,6)
Gastric Acid
60
What are 3 antibacterial components of Saliva?
Lysozyme (targets walls)
Lactoferrin (chelates iron)
IgA
61
How many species of bacteria are in the oral cavity?
700
62
Name 4 oral bacteria and 1 anaerobe.
Streptococci
Lactobacilli
Staphylococci
Corynebacteria
Bacteroides
63
Three benefits of normal oral cavity flora.
Prevent colonization
Inhibition of non-indigenous species
Stimulates cross reactive antibodies
(antibody immune response)
64
T/F
| Saliva contains buffering agents and minerals
true
65
At what pH can enamel be dissolved?
below 5.5
66
Where is the salivary center?
Medulla
67
Describe what the sympathetic response does for Salivary Output.
Scant
Protein rich
High K+ and HCO3-
68
T/F
| Sympathetic and parasympathetic stimulation increase salivary secretion.
True
*but very different in character
69
What agents reduce salivary secretion?
Atropines
| Cholinergic blockers
70
How many different chemicals can taste buds detect?
4-10k
71
Name 3 types of papillae.
Fungiform
Foliate
Circumvallate
72
What papilla is scattered over the entire tongue and responds to sweet and salty (and sour)?
Fungiform
73
What papilla responds mainly to sour?
Foliate
74
What are fungiform papillae taste buds innervated by?
| Circumvallate?
CN VII - chorda tympani branch
| CN IX - glossopharyngeal
75
What papillae responds best to bitter substances?
Circumvallate
76
Taste buds in the epiglottis are innervated by...
X - vagus
77
Taste buds in the palate are innervated by...
VII - facial nerve
78
T/F
| Taste receptor cells are neurons
False
but synapse onto VII, IX, and X
79
What is at the taste pore?
Microvilli
80
What taste depolarizes membrane through influx of Calcium and sodium and inhibiting K+ efflux via cAMP?
Bitter
81
What taste goes through cascade ultimately releasing calcium into the cell?
Alkaloid
| ??
82
What taste relies on influx on Na+?
Salty
83
What taste relies on H+ to block channel and impede K+ from exiting the cell?
Sour
84
What taste acts through cAMP and PKA to inhibit K+ from exiting cell thus depolarizing the membrane?
Sweet
85
Where do gustatory cranial nerves terminate?
Solitary nucleus in the medulla
| Rostral 1/2
86
Where does output of the Nucleus of the Solitary Tract lead?
| 2 places
Ventroposterior medial nucleus of the Thalamus
(VPM)
Insular Cortex
*this is why bad taste in mouth after seizure
87
T/F
| Lower 3rd molar extraction causes gustatory loss by impacting the Lingual Nerve
False
| only temporary, and not detectable by pt
88
The lingual nerve is a branch of...
Trigeminal (mandibular division)
*sensory innervation to the tongue
89
4 muscles of mastication.
Temporalis
Lateral Pterygoid
Medial Pterygoid
Masseter
90
What innervates the muscles of mastication?
V Mandibular Division
91
Action and innervation Masseter:
Elevate mandible
| Masseteric branch Mandibular V
92
Temporalis Action and innervation:
Elevates mandible
| Deep temporal branch Mandibular V
93
Lateral Pterygoid action and innervation:
Protrudes mandible
| Lateral pterygoid branch Mandibular V
94
Medial Pterygoid action and innervation:
Elevates mandible
| Medial pterygoid branch Mandibular V
95
Depression, elevation, lateral, and anterior-posterior movement creates what in the jaw?
Looping pattern
96
Three phases of mastication:
Opening
Closing
Occlusal (longest component)
97
What depresses the mandible?
| 3 muscles, 1 force
Gravity
Digastric
Geniohyoid
Mylohyoid
98
How long is the esophagus?
| Thick?
18-26 cm
2 cm (ant/post)
3cm (lateral)
99
What vertebral level does the esophagus begin?
traverse diaphragm?
cardi of orifice?
C5-6
T10
T11
100
What type of epithelium is the esophagus lined with?
non-keratinized stratified squamous
101
What provides mucus for the esophagus?
Esophageal Glands
102
3 layers of esophageal wall?
Mucosa
Submucosa
Muscularis
103
What anatomical difference is there in the esophagus compared to the rest of the GI tract?
No Serosal outer layer
| thin connective tissue instead
104
T/F
| The esophagus has small veins
False
especially large gastric veins
105
What can cause bumps in the esophagus?
What is this called?
Submucosal venous spaces fail to drain
Esophageal Varices
106
What causes esophageal varices?
portal hypertension
*cirrhosis
107
3 phases of Deglutition (swallowing):
Oral/voluntary
Pharyngeal
Esophageal
108
What relaxes in the Involuntary pharyngeal phase?
Upper Esophageal Sphincter
109
What accounts for the inhibition of respiration and stimulation of glottic closure during deglutition?
Reflex Response
110
Peristalsis in the esophagus terminates at:
Lower Esophageal Sphincter
111
What condition entails the Lower Esophageal Sphincter's inability to relax?
Achalasia
* doesn't open
* entire meals back up this way
112
What common condition leads to heartburn and esophagitis (and ulceration and scarring)?
GERD - gastroesophageal reflux disease
113
What causes GERD?
What really bad thing is associated with it?
decrease in LES pressure
(doesn't close)
esophageal adenocarcinoma
114
T/F
| Steroidal based oral contraceptives decrease closing strength of the LES
True
| along with caffeine, peppermint, spicy, citrus, smoking
115
What is a complication from persistent GERD?
Barrett's esophagus and strictures
116
What causes strictures from persisted GERD?
Scar tissue, spasm, and edema
117
What do strictures in the esophagus cause?
Difficulty swallowing (dysphagia)
118
What is the term for painful swallowing?
Odynophagia
119
What indicated Barrett's esophagus when looking down esophagus?
Red lining
| with "tongues" indicating erosion
120
What replaces squamous mucosa in Barrett's esophagus?
```
Columnar epithelium
(resembling stomach/intestine)
```
121
What are the 4 main regions of the stomach?
Cardia
Fundus
Body
Pylorus
122
What are the 2 sphincters in the stomach?
LES - Lower Esophageal Sphincter
| Pyloric
123
What defines the border of the Fundus to the Body?
Cardial notch
124
Where does the Greater Omentum hang from?
Greater curvature of the stomach
125
What are the 3 layers of muscularis musosa in the stomach?
Longitudinal (outer)
Circular (middle)
Oblique (inner)
126
What acts as the protective barrier in the gastric lining?
Alkaline mucus
| with a lot of Bicarb
127
What enhances mucous production in the stomach?
Prostaglandins
128
What is the turnover rate of the lining of the stomach?
2-3 days
129
What type of epithelium is in the stomach?
Simple columnar
130
What are the deep channels in the simple columnar epithelium of the stomach?
Gastric pits
131
What are the 4 main gastric glands?
Mucous neck cells
Parietal Cells
Chief cells
Endocrine cells
132
What type of cells secrete the alkaline mucous?
Mucous neck cells
133
What to Parietal cells secrete?
HCL and IF
134
What do Chief cells secrete?
Pepsinogen
| Gastric Lipase
135
What cells secrete gastrin and histamine?
| Specifically?
Endocrine cells
G cells - gastrin
ECL (enterochromaffinlike) - Histamine
136
How much gastric juice is secreted daily?
2500 mL
137
Where are most Parietal cells located in the stomach?
Where are most Chief cells located?
G cells?
High body toward fundus
Body
Antrum
138
What does Gastrin stimulate?
Parietal cells (IF and HCL)
139
What 2 hormones are secreted by the stomach?
Gastrin
| Histamine
140
What is chyme?
Mixed food
| combined with gastric juice
141
What causes the Alkaline Tide?
HCl production in Parietal cells from Bicarb
HCO3- released into blood and causes temporary alkalinity
142
T/F
| The vagus nerve stimulates gastric secretion while food is still in the mouth (cephalic phase).
True
143
Describe the positive feedback loop in the stomach.
*What phase does this take place?
Gastrin (via vagal or distention stimuli)
stimulates gastrin secretion
(which stimulates more Gastrin, etc)
*Gastric Phase
144
What increases HCL secretion from parietal cells?
Histamine
145
How does Pepsin break apart AA's?
Partially
| can only cut certain linkages
146
What 3 hormones in the duodenum act to decrease gastric juice secretion?
CCK
Secretin
GIP (gastric inhibitory peptide)
147
What hormone released by the duodenum inhibits gastric motility?
GIP
148
What 3 signals stimulate H+ secretion in the stomach?
Histamine
Gastrin
Vagal (via Ach)
149
What inhibits the vagus nerve activity that stimulates the stomach?
Enterogastric Reflex
150
CCK, secretin, and GIP all _____ gastric motility and emptying
inhibit
151
What can cause acute gastritis?
Bacterial endotoxins, alcohol, aspirin, etc
152
What can cause chronic gastritis?
Helicobacter pylori
153
What does H. pylori produce that allows it to live in the stomach?
Urease
| NH3 neutralizes stomach acid
154
What condition entails the prolapse of the stomach through the diaphragmatic/esophageal hiatus?
Hiatal Hernia
155
T/F
| Hiatal hernias are more common in men
False
pregnancy pushing
156
T/F
| Abdominal ascites is associated with hiatal hernia
True
157
Where is B12 absorbed?
Terminal ileum
158
T/F
| Pernicous anemia is characterized by megaloblasts that lack biconcavity and live for days
False
Live for weeks rather than months
159
What are 2 oral manifestations of Pernicious Anemia?
```
Erythma/atrophy of tongue
Megaloblastic anemia (red lesions in mucosa)
```
160
4 consequences of Emesis.
Acid-base disorders
volume/electrolyte depletion
Malnutrition
Aspiration Pneumonia
161
What phase of emesis is the antrum contracting and the cardia relaxing?
Retching
162
How does the diaphragm contract during emesis?
Downward
*facilitates opening of esophagus and LES
163
What two muscles are simultaneously contracted in emesis?
Diaphragm downward
| Abdominals
164
What controls vomiting in brain?
Bilateral Vomiting Centers
165
What is located on the floor of the 4th ventricle in the brain?
Chemoreceptor Trigger Zone
*can initiate vomiting
166
What salivary flow rate is used to diagnose Sjogrens?
Less than 0.1 mL/min
167
What 2 classes of drugs cause Xerostomia?
Anti-Muscarinics
| Beta-2 Agonists
168
Example of a LABA (Long Acting Beta-2 Agonist) used to prevent asthma.
Salmeterol
169
Muscarinic Antagonist used as a bronchodilator.
Ipratropium
170
Muscarinic Antagonist used for Incontinence (also increases heart rate)
Oxybutynin
171
What anti-histamine decreases salivary production?
Benadryl
172
Diuretic that decreases salivary secretion due to overall body fluid loss.
Hydrochlorothiazide
173
Nasal decongestant and vasoconstrictor that decreases salivary action.
Phenylephrine
174
Muscarinic Antagonist
Benztropine
175
How does Pilocarpine (Salagen) increase salivation?
Stimulates Muscarinics
176
How does Cevimeline (Evoxac) stimulate salivation?
Muscarinic Agonist (Ach mimicker)
177
What lubricant rinse helps with Xerostomia?
Biotene Oral Balance
178
T/F
| Steroids (like Fluticasone) causes dry mouth
True
179
What is a very common side effect of corticosteroids?
Thrush (Candida albicans)
180
What is the best treatment for Oral Thrush?
Fluconazol
181
Why do non-specific Cox inhibitors cause stomach pain?
Decreases Prostaglandin activity and depletes stomach lining
182
What is the physiological prostaglandin?
| Inflammatory?
Cox 1
| Cox 2
183
What two antibiotics are prescribed for Peptic Ulcer Disease?
Clarithromycin
| Amoxicilin
184
What drug acts as a PPI (Proton Pump Inhibitor)?
Esomeprazole
185
What drug acts as a Histamine-2 Receptor Blocker?
| and partially inhibits H+ gastric secretion
Ranitidine
