GI disorders part 1 Flashcards
1
Q
What is the primary function of the GI system?
A
- ingestion
- digestion
- absorption
- elimination
2
Q
What should you also evaluate when assessing the GI tract?
A
- swallowing
- eructation (burp)
- trush
- abd pain
- emesis
3
Q
What is the esophagus?
A
tube-like structure that lies behind the trachea in the thorax and extends from the pharynx to the stomach (approx 10 inches)
4
Q
What does the esophagus consist of?
A
- smooth muscle layer
- mucosal & submucosal glands
- a sphincter at either end of the esophagus
- upper (pharyngoesophageal)
- lower (gastroesophageal)
5
Q
What do the mucosal & submucosal do?
A
secrete mucus; provide surface protection & lubrication
6
Q
What does the upper sphincter (pharyngoesophageal) do?
A
striated muscle; prevents air from entering the esophagus during breathing
7
Q
What does the lower sphincter (gastroesophageal) do?
A
circular muscle; passes thru opening in the diaphragm (hiatus)
- reflux prevention
8
Q
How does food move through the esophagus?
A
by peristalsis
9
Q
What does the stomach consist of?
A
- fundus (upper portion)
- body
- pylorus
10
Q
What are the three phases of the digestive process?
A
- cephalic phase
- gastric phase
- intestinal phase
11
Q
What are the functions of gastric acid?
A
- chemical breakdown of food
- disinfect ingested food
12
Q
What are the the cells found in the stomach?
A
- gastric goblet cells
- parietal cells
- chief cells
- G cells
13
Q
What do parietal cells secrete?
A
HCL & intrinsic factor
14
Q
What do chief cells secrete and what does it do?
A
pepsinogen
- converts to pepsin which aids in protein breakdown
15
Q
What do G cells secrete?
A
gastrin
16
Q
What do parietal cells act as?
A
- proton-pumps
- histamine receptors
17
Q
Where is there a high concentration of prostaglandin?
A
high concentrations in gastric mucosa & secretions
18
Q
What do prostaglandins do in the GI tract?
A
- inhibit secretion
- stimulate mucus & bicarbonate secretion
19
Q
What is the function of goblet cells?
A
secrete mucus
20
Q
What is the function of parietal cells?
A
- secretes HCL: sterilizes & breaks down food (mainly PRO & CHO)
- secrete intrinsic factor: needed to absorb B12 in small intestine
- acid synthesis is controlled by proton pump: pump triggers include acetylcholine, histamine & gastrin
21
Q
What is the function of chief cells?
A
secrete pepsinogen; converts to pepsin (enzyme for protein digestion)
22
Q
What is the function of gastric mucosal cells?
A
secretes prostaglandin E2 (PGE2)
- protects GI tract
- stimulates gastric mucus production & pancreatic bicarb secretion
23
Q
What is the function of G cells?
A
secretes gastrin
- PRO digestion
- increases gastric motility, stimulate secretions from parietal & chief cells, triggers release of bile from gallbladder and enzymes from pancreas
24
Q
How does gastric emptying work?
A
- A peristaltic contraction originates in the upper fundus & sweeps down toward the pyloric sphincter
- the contraction becomes more vigorous as it reaches the thick- muscled antrum
- strong antral peristaltic contraction propels the chyme forward
25
How does gastric mixing work?
1. when the peristaltic contraction reaches the pyloric sphincter, the sphincter is tightly closed and no further emptying takes place
2. when chyme that was being propelled forward hits the closed sphincter, it is tossed back into the antrum. mixing of chyme is accomplished as chyme is propelled forward & tossed back into the antrum
26
How long is the middle GI tract?
approximately 20 feet long
27
What does the middle GI tract consist of?
- duodenum
- jejunum
- ileum
28
What does the duodenum perform and what does it consist of?
- performs digestion
- contains opening for common bile duct & main pancreatic duct
29
What does the jejunum perform?
- performs digestion
- amino acids, glucose, Fe, Ca, fat-soluble vitamins (A,D,E,K)
30
What does the ileum perform?
- performs reabsorption
- enterohepatic circulation (primary function reabsorption of vit B12 & return of bile acids to liver)
31
What is the ileocecal valve?
where the small & large intestine join
32
What is the mucosal lining of the small intestine covered in?
covered in villi (finger-like projections)
33
What does each villi have?
Each villi has 1 artery, vein, & lymph vessel
34
What kind of cells are villi made up of?
enterocytes
35
What do enterocytes do?
- Secrete brush border enzymes
- aid in digestion of carbohydrates & protein
36
How do brush border enzymes work?
- molecules diffuse thru membrane OR actively transport across mucosal surface
- enters blood OR fatty acids (thru lacteal)
- then goes thru portal vein or lymphatic into systemic circulation
37
What is the major function of the intestinal microflora?
- metabolic activities that salvage energy &
38
What is the lower GI tract also known as?
the large intestine
39
How long is the large intestine?
4.5 - 5 feet
40
What is the lower GI tract composed of?
- cecum
- ascending
- transverse
- descending
- sigmoid colon (waste products)
- rectum
- anal canal
41
What is the role of the lower GI tract?
to absorb water & salt and to store feces until defecation
42
What is the gastrointestinal wall made up of?
is a four-layered tube
- first (inner mucosal) layer
- second (submucosal) layer
- third (muscularis externa) layer
- fourth (serosal) layer
43
What is the first (inner mucosal) layer made up of?
made up of lining of epithelial tissue known as lamina propria & the muscularis mucosae
44
What are the functions of the first (inner mucosal) layer?
- production of mucus
- secretion of digestive enzymes
- absorption of the breakdown products of digestion
- maintenance of a barrier; immune defense
45
What does the second (submucosal) layer consist of?
contains blood vessels, nerves, & structures responsible for secreting digestive enzymes
46
What does the third (muscularis externa) layer consist of?
consists of two layers of smooth muscle cells that facilitate movement
- inner layer: smooth muscle cells in circular pattern
- outer layer: smooth muscle cells longitudinally arranged
47
What does the fourth (serosal) layer consist of?
is a serous membrane consisting of the mesothelium
- outer layer: visceral peritoneum
- inner layer: parietal peritoneum
48
What are the mesenteries of the abdominal cavity?
- double-folded connective tissue that attached the intestines to the posterior abdominal wall
- consists of 3 sections
49
What do the mesenteries of the abdominal cavities help with?
- help in supplying blood vessels, lymphatic & nerves to the intestines
- helps in storing fat
50
What are the two types of intestinal motility?
- segmental mixing/ kneading movements (haustrations)
- propulsion or propulsive mass movements
51
What is the primary type of intestinal motility?
segmental mixing/kneading movements (haustrations)
52
What is segmental mixing?
- shuffling of contents back and forth among haustra
- increases contact time with mucosa for absorption of water & electrolytes
53
When do propulsion or propulsive mass movements usually occur?
usually occur after a meal
54
What are propulsive mass movements?
large segment contracts and moves contents forward into sigmoid colon & rectum to simulate defecation
55
What do smooth muscle cells function as?
the pacemaker cells for the GI tract
- slow waves: 3-12 per minute
56
What does the regulatory control of intestinal motility result from?
an interplay between the enteric, autonomic nervous system & intestinal smooth muscle cells
57
What is the myenteric (auerbach) plexus?
- located between circular & longitudinal muscle layers
- gut motility
58
What is the submucosal (meissner) plexus?
- between the mucosal & muscle layer
- controls secretion, absorption, and contraction of segments in the intestinal tract
59
What is the enteric nervous system regulated by?
local influences (mechanoreceptor/chemoreceptors)
- ANS & information between the plexuses
60
What is parasympathetic innervation supplied by?
the vagus nerve
61
What does stimulation of the parasympathetic nervous system cause in the GI tract?
increased motility & secretions
62
What does sympathetic innervation cause in the GI tract?
decreased motility & secretory activity
63
What stimulates the sympathetic nervous system?
Stimulation is inhibitory
64
What begins the digestive process?
mastication
65
What is swallowing & esophageal motility?
propulsion of food from mouth to stomach
66
What are the three phases of swallowing?
1. oral
2. pharyngeal
3. esophageal
67
What are the two types of peristalsis in swallowing & esophageal motility?
- primary
- secondary
68
What is primary peristalsis?
controlled by the swallowing center & begins when food enters the stomach
69
What is secondary peristalsis?
partially mediated by smooth muscle fibers in the esophagus
- esophageal sphincter
- parasympathetic stimulation
- gastrin
70
What does the stomach serve as in gastric motility?
stomach serves as a food storage reservoir
71
What is chyme?
Food is broken down into a creamy mixture
72
What does gastric motility result in?
results in mixing a solid food & emptying gastric contents into the duodenum
- 2-3 contractions per minute
73
What does the antrum do in gastric motility?
releases gastrin, which stimulates gastric acid production
74
What is the role of the pyloric sphincter?
prevents the backflow of gastric contents & allows them to flow into the duodenum
75
What is the role of the small intestine?
site of digestion & absorption of food
76
What are the two types of small intestine movements?
- segmentation
- propulsive
77
What is a normal colonic transit time?
24-48 hrs
78
What does normal stool consist of?
consists of 75% water & 25% solid matter
79
What is defecation controlled by?
internal & anal sphincters
80
What are the hormones related to the GI tract?
- cholecystokinin
- gastrin
- ghrelin
- glucagon-like peptide 1
- glucose-dependent insulinotropic polypeptide
- secretin
81
What are the different secretions in the GI tract?
- salivary
- gastric
- pancreatic
- biliary
- intestinal
82
How much fluid is secreted in the GI tract daily?
approximately 7000ml
83
What is digestion?
process of dismantling foods into their constituent parts
84
What is required for digestion?
- hydrolysis
- enzyme cleavage
- fat emulsification
85
What is hydrolysis?
breakdown of a compound; involves a chemical reaction w/ water
86
What is fat emulsification?
breakdown of fats into free fatty acids & monoglycerides
87
What organs are in the RUQ?
- liver (majority)
- Rt kidney
- clon
- pancreas (small portion)
- gallbladder
- small intestine
88
What organs are in the RLQ?
- colon
- small intestines
- rt ureter
- appendix
- rt ovary/ rt fallopian tube
89
What organs are midline?
- bladder
- uterus
- prostate
90
What organs are in the LUQ?
- liver (small portion)
- spleen
- lt kidney
- stomach
- pancreas (majority)
- small intestine
91
What is in the LLQ?
- colon
- small intestine
- lt ureter
- lt ovary/fallopian tube
92
What disorders are associated with the epigastric area?
- esophagitis
- pancreatitis
- perforated ulcer
- acute cholecystitis
- myocardial infaction
93
What disorders are associated with the RUQ?
- hepatitis
- duodenal ulcer
- acute cholecystitis
94
What disorders are associated with the RLQ?
- hernia
- appendicitis
- ovarian cyst
- kidney stones
- pyelonephritis
- ectopic pregnancy
- salpingitis (female)
- mesenteric diverticulitis
- mesenteric adenitis
- bowel obstruction/perforation/ ischemia
- IBD
95
What disorders are associated with the LUQ?
- gastric ulcer
- ruptured spleen
- aortic aneurysm
- pancreatitis
96
What disorders are associated with the LLQ?
- hernia
- diverticulitis
- ovarian cyst
- kidney stone
- pyelonephritis
- ectopic pregnancy
- bowel obstruction/ perforation/ ischemia
- IBD
97
What are the three types of abd pain?
-parietal
- visceral
- referred
98
What is parietal abd pain?
- localized
- described as knife-like, sharp
99
What is visceral abd pain?
- distention/inflammation of body organs
- described as colicky,crampy
100
What produces abdominal pain?
biochemical mediators of the inflammatory response (histamine, bradykinin, serotonin) stimulate nerve endings to produce abd pain
101
What are abd organs sensitive to?
stretching & distension
102
What are disorders of the esophagus, stomach, & small intestine?
- dysphagia
- achalasia
- esophagitis
- GERD
- upper GI bleed
- esophageal varices
- esophageal cancer
- hiatal hernia
- pyloric stenosis
- **peptic ulcer disease**
- bariatric surgery
- dumping syndrome
- hernia
- gastroenteritis
- **celiac disease**
- short-bowel syndrome
- small bowel obstruction
- peritonitis
103
What is GERD?
a backward movement of gastric contents into the esophagus
104
How does a normal functioning GI prevent GERD?
a normal functioning lower esophageal sphincter maintains a zone of high pressure to prevent chyme reflux
105
When does the lower esophageal sphincter relax and what can that cause?
the lower esophageal sphincter relaxes spontaneously 1-2 hrs after eating, which allows regurgitation into the esophagus
106
What percent of the US population is affected by GERD?
20-40%
107
What two conditions can esophageal mucosal damage lead to?
- erosive esophagitis
- Barrett esophagus
108
What causes/ what is barrett esophagus?
- Repeated injury causes metaplasia
- change to columnar epithelium
- precancerous (esophageal adenocarcinoma
109
May people ______________ for GERD
self-medicate
110
How is GERD diagnosed
endoscopy & manometry
111
What can cause GERD?
certain conditions, substances, foods & medications can weaken or hinder closure of the lower esophageal spincter
112
What are examples of things that can cause GERD?
- alcohol
- acidic food
- fatty foods
- chocolate
- coffee
- nicotine
- obesity
- pregnancy
- hiatal hernia
- meds: anticholinergics, beta-agonists, CCBs, nitrates, progesterone
113
What are the clinical manifestations of GERD?
- dysphagia
- heartburn
- regurgitation
- bitter taste
- upper abd pain within 1 hr of eating
- increase pain w/ lying or increased intra abd pressure
- can have sx with no acid
- cough, increase in asthma sx
- may seem like angina
114
What are non-pharmacologic tx of GERD?
- Decrease dietary fats
- eat small meals
- stop smoking
- avoid lying down for 3 hrs after eating
- avoid alcohol
- weight loss
- elevate head of bed
115
What are pharmacological tx of GERD?
- antacids
- histamine (H2) blockers
- proton pump inhibitors
- prokinetic agents
116
What is celiac disease?
an autoimmune disorder triggered by gluten
117
What are the clinical manifestations of celiac disease?
- abd pain
- bloating
- diarrhea
- weight loss
- steatorrhea
- weakness
- flatulus
- fatigue
118
What is used to dx celiac disease?
- H & H
- CMP
- genetic testing
- IgA
- antibody testing
119
What is the tx for celiac disease?
- Remove gluten from the diet
- vitamin replacement
- corticosteroids
120
What percent of the worlds population is affected by helicobacter pylori?
50-75%
121
who is at an increased risk for H pylori?
Hispanics and African Americans
122
How is H pylori spread?
person to person through saliva, feces, & vomit
123
What are common causes of H pylori?
- peptic ulcers
- gastritis
- gastric (stomach) cancer
124
most people with H pylori are ________________
asymptomatic
125
What kind of bacterial is H pylori?
gram-negative rods that colonize in the mucus-secreting epithelial cells of the stomach
- small, curved or spiral shaped gram-negative rods
126
What does H pylori secrete and what does that do?
- secretes urease, which converts urea to ammonia
- ammonia neutralizes acidity of stomach for bacteria to survive
127
Where does H pylori burrow into?
mucus layer
128
What does H pylori do?
produces enzymes & toxins
- impacts protection of mucosa to acidic environment
- intense inflammatory response
- creates immune response: T & B cells
129
What are sx of H pylori?
- Many are asymptomatic
- dull burning pain in the abdomen
- increase pain with an empty stomach
- N/V
- dyspepsia
- bloating
- weight loss
130
How is H pylori dx?
- urea breath test
- serologic tests
- stool antigen test
- endoscopic biopsy
131
How is an H pylori infection tx?
- antibiotics
- bismuth (antibacterial effect)
- PPI (raise the pH)
- H2 blockers
132
What is peptic ulcer disease?
inflammatory erosion in stomach (gastric ulcer) or duodenal lining (duodenal ulcer)
133
Where does peptic ulcer disease occur?
occurs in the upper portion of the GI tract
134
What is the pathophysiology of peptic ulcer disease?
- hypersecretion of HCL
- ineffective mucous production
- poor cellular repair
135
Is peptic ulcer disease chronic?
no; there are periods of exacerbation & remission
136
In what age group is peptic ulcer disease seen most?
middle aged individuals
137
What are the causes of peptic ulcer disease?
- H pylori
- chronic aspirin or NSAID use
- stress
- alcohol
138
How does H pylori cause erosion of mucosal lining?
- HCL diffuses into stomach wall & blood vessels
- creases inflammatory response causing the release of histamine & prostagandin
139
What does histamine do after being releases in the mucosal lining?
- causes vasodilation & stimulates pepsin & gastrin release
- acid secretion stimulated which attacked unprotected lining
140
What does HCL do in H pylori response?
- released by parietal cells
- irritates & destroys lining & continues to trigger inflammation
141
How does scarring and fibrosis of lining happen in H pylori?
- Fibrosis inhibits healthy cell reproduction
- decreased mucus & bicarb production to protect lining
142
Where do gastric ulcers occur?
the stomach
143
H pylori can lead to the development of
- erosion
- ulcers that can extend into the muscularis layer
144
When is pain experienced when gastric ulcers are present>
epigastric pain 1-2 hrs after eating
145
What can gastric ulcers cause?
- hematemesis or melena
- gastric carcinoma
146
What sx are commonly seen with gastric ulcers?
- heartburn
- chest discomfort
- early satiety
147
Where do duodenal ulcers occur?
occur in the duodenum
148
When is pain experienced wth duodenal ulcers?
epigastric pain 2-3 hrs after eating
149
What can duodenal ulcers cause?
melena or hematochezia
150
What may a pt with duodenal ulcers experience?
may have pain waken them during night
151
What sx may be seen with duodenal ulcers but are less common?
heartburn & chest discomfort
152
Where in the stomach do gastric ulcers occur?
tend to develop in the antral region of the stomach, adjacent to the acid-secreting mucosa of the body
153
In what age and gender are gastric ulcers common?
ages 55-65 male & female
154
What is the pathophysiology of gastric ulcers?
- primary defect is an increased mucosal permeability to hydrogen ions
- frequent H pylori
- gastric secretion is normal to less than normal
155
What is the most common type of peptic ulcer disease?
duodenal ulcer
156
What causes duodenal ulcers?
- h pylori
- smoking
- nsaids
- stress
- genetic predisposition
157
why does epigastric pain occur 2-3 hrs after eating with duodenal ulcers?
- increased gastrin levels that stay high after eating, continue to stimulate the secretion of acid
- impaired duodenal bicarb secretion
- failure of feedback where acid in the antrum inhibits the gastrin release
- rapid gastric emptying overwhelms buffering
158
What are the clinical manifestations of duodenal ulcers?
- chronic intermittent pain in epigastric area
- pain increases aout 30 min to 2 hrs after eating
- night time pain between 11-2
- spasm & acid
- relieved w/ food & antacids
159
What are the clinical manifestations of gastric ulcers?
- pain tends to increase after eating
- belching
- early satiety
- anorexia
- N/ V
- weight loss
- tends to be chronic
160
what clinical manifestations do duodenal & gastric ulcers have in common?
- Both can cause melena or hematemesis
- can lead to hemorrhage, perforation, gastric outlet obstruction
161
what are goals of PUD tx?
- promote healing
- relieve pain
- decreased acid levels
- prevent recurrence
162
What lifestyle changes should be made to tx PUD?
avoid:
- caffeine
- alcohol
- tobacco
- spicy food
- high fat food
- ASA
- NSAIDs
163
What pharmacological tx can be used for PUD?
- antibiotics
- PPIs
- H2 inhibitors
