Chapter 36 - Alterations in Digestive Function Flashcards
1
Q
How does the digestive tract structure vary from mouth to anus?
A
it doesn’t, it is all the same
2
Q
Name the 4 layers of the digestive tract from deep to superficial:
A
- mucosa (innermost)
- submucosa
- muscularis externa
- serosa (outer layer)
3
Q
What does the mucus layer protect?
A
mucosa (epithelial layer)
4
Q
How many mucus layers does the small intestine have?
A
1
5
Q
How many mucus layers does the large intestine have?
A
2; an inner and outer
6
Q
How do structural and neural GI tract disorders disrupt digestion?
A
obstruction, slowing, or accelerating contents
7
Q
How do inflammatory and ulcerative GI tract disorders disrupt digestion?
A
disrupt secretion, motility, absorption
8
Q
How do disorders of accessory organs disrupt digestion?
A
by altering metabolism
9
Q
What are the accessory digestive organs?
A
liver, gallbladder, pancreas
10
Q
What is the Greek word for vomiting?
A
Emesis
11
Q
Vomiting Definition
A
forceful emptying of stomach or intestinal contents through the mouth
12
Q
Where is the vomiting centre in the brain?
A
medulla oblongata
13
Q
What is retching?
A
a muscular event of vomiting without vomitus expulsion
14
Q
What is projectile vomiting?
A
spontaneous vomiting that does not follow nausea or retching
15
Q
What causes projectile vomiting?
A
direct stimulation of the vomiting centre in the medulla oblongata
16
Q
Abdominal Distention
A
swelling of the abdomen
17
Q
Vomiting usually follows _____ or ______ of the stomach or duodenum.
A
pain or distension
18
Q
When vomiting is initiated, it starts with a deep __________ and the closure of the ______.
A
inhalation; glottis
19
Q
What creates pressure from stomach to throat before vomiting?
A
abdominal muscles
20
Q
Which parts of the GI tract spasm and force chyme into the esophagus?
A
duodenum (sm. intestine) and antrum (stomach)
21
Q
When vomiting is initiated which esophageal sphincter stays closed so the contents can’t enter the mouth?
A
upper esophageal sphincter
22
Q
What returns contents to the stomach when vomiting is initiated?
A
relaxation of the abdominal muscles
23
Q
The process of forcing intestinal contents up and down is repeated several times until the ____________ nervous system relaxes both esophageal sphincters.
A
parasympathetic
24
Q
How is stomach chyme forced out of the mouth?
A
contraction of the abdominal muscles to force the diaphragm high into the thorax
25
What is constipation?
difficult or infrequent defecation
26
Why is constipation individually determined?
people have different pooping schedules ie. some are 1-3x daily and others may be once a week
27
Primary Constipation
impaired, infrequent, straining colonic movement
28
Secondary Constipation
due to altered neural pathways that delay colon transit time
29
Which drugs inhibit bowel movement?
opiates (mainly codeine)
30
A notable change in constipation can indicate:
colorectal cancer
31
Straining to poop may cause...
hemorrhoids
32
How are hemorrhoids/constipation diagnosed?
-sphincter tone assessment
-detection of anal lesions
-colonoscopy
33
3 Ways to Treat Constipation:
1. over the counter laxatives (RestoraLAX)
2. enema
3. colectomy
34
Enemas are used to establish bowel _______, and should not be used habitually
routine
35
Colectomy
surgical removal of part of the colon
36
Diarrhea
loose watery stool
37
Acute diarrhea lasts ____ hours or less
24
38
How long does persistent diarrhea last?
14-28 days
39
How long does chronic diarrhea last?
longer than 4 weeks
40
Diarrhea poses high morbidity/mortality rates for children under ___
5
41
Osmotic diarrhea occurs when...
non-absorbable substances in the intestine draw excess water into the intestine
42
Secretory diarrhea occurs with...
excessive mucosal secretion of fluid and electrolytes
43
What are two causes of secretory diarrhea?
viruses and bacterial toxins
44
Rotavirus is a ____ virus that causes _______
RNA; enteritis
45
Enteritis
inflammation of the intestinal system
46
Motility diarrhea occurs when...
excessive motility decreases transit time and reabsorbtion
47
Motility diarrhea occurs with ________ bypass of intestinal area
surgical
48
How is diarrhea treated?
-fluid and electrolyte restoration
-anti-motility and water absorbent medication
49
Abdominal pain can be caused by ________, __________, or _________ factors
mechanical, inflammatory, or ischemic
50
With abdominal pain, what activates pain receptors?
stretching or distention of abdominal organs
51
Parietal pain arises from the parietal peritoneum which is the ________ membrane
outer
52
Parietal pain is ________ and intense
localized
53
Visceral pain arises from distention, inflammation, or ischemia of __________ _______
abdominal organs
54
Visceral pain is ______ _______ and ________
poorly localized and radiating
55
Bleeding in which 3 areas is considered 'upper' gastro-intestinal bleeding?
esophagus, stomach, duodenum
56
Upper GI bleeding is which colour and why?
Bright red due to effects of stomach acids
57
What causes upper GI bleeding?
-peptic ulcers
-tearing of esophageal gastric junction caused by severe retching
58
Bleeding in which 4 areas is considered 'lower' gastro-intestinal bleeding?
jejunum, ileum, colon, rectum
59
What are 3 causes of lower GI bleeding?
-polyps
-inflammatory disease
-hemorrhoids
60
Occult bleeding is not obvious and occurs due to slow ______ blood loss
chronic
61
Occult bleeding results in an ______ deficiency (anemia)
iron
62
GI bleeding presents as blood in ______, ______ ______ reduction, compensating _________, or ______ loss
stool; blood pressure; tachycardia; vision
63
Why does vision loss occur sometimes with GI bleeding?
the blood vessels in the eye are the smallest so they are the first to suffer
64
Dysphagia
difficulty swallowing
65
Mechanical Obstruction of Esophagus
obstruction in esophageal wall due to tumour or herniations
66
Functional dysphagia occurs due to a ______/_______ disorder that interferes with swallowing
neural/muscular
67
Achalasia is a rare form of _________
dysphagia
68
Achalasia occurs when the ______ muscle neurons of the middle/lower esophagus are attacked by ____________
smooth; immune response
69
Achalasia results in altered ________, failure of the _____ to relax, cough and aspiration
peristalsis; LES (lower esophageal sphincter)
70
What does GERD stand for?
Gastroesophageal Reflux Disease
71
Esophagitis may be caused by...
reflux of acid (pepsin) or bile salts into the esophagus
72
GERD is caused by a)_____ b) ________
a) LES abnormality (lower resting tone)
b) Delayed gastric emptying of chyme
73
The severity of damage on the esophagus due to GERD depends on the __________ and ________ of reflux
composition and duration
74
Prolonged acidic chyme exposure can lead to ______ injury
mucosal
75
Persistent GERD can lead to...
fibrosis thickening and precancerous lesions
76
How is GERD diagnosed? (2)
-esophageal endoscopy
-tissue biopsy
77
GERD is treated using laparoscopic fundoplication meaning...
surgical tightening of the junction between the esophagus and stomach to prevent acid reflux
78
What is a hiatal hernia?
protrusion of the superior aspect of the stomach through the diaphragm hiatal into the thorax
79
A sliding hiatal hernia occurs when the stomach moves into the thorax _______ the esophageal hiatus
through
80
A paraesophageal hiatal hernia occurs when the stomach moves _____ the thorax ________ the esophageal hiatus
into; alongside
81
What is an emergent risk of a hernia?
strangulation
82
How are hiatal hernias diagnosed?
radiology with barium swallow
83
How are hiatal hernias treated? (2)
-sleeping with head up
-laparoscopic fundoplication
84
What is an intestinal obstruction (IO)?
any condition that prevents the normal flow of chyme through the intestinal lumen
85
What is a paralytic ileus (PI)?
a functional obstruction resulting from the failure of intestinal motility due to dysfunctional neural activity post op
86
A large bowel obstruction (LBO) is ______ common but often related to _______
less; cancer
87
What are the signs an symptoms of a Large Bowel Obstruction?
abdominal distension and vomiting
88
Small bowel obstructions (SBO) are caused by ______________ that lead to distensions
post-operative adhesions
89
SBO results in 5 things. Which of these are true?
A) Constipation from decreased motility
B) Distension that impairs absorption
C) Sepsis due to leakage of pathogens
D) Blood in stool
E) Increased secretion leading to gas, fluid, and solute accumulation
F) Fluid movement into the lumen
G) The lumen becoming acidic
B, C, E, F, G
90
With a SBO, what is the result of systemic ECF moving into the lumen? (3)
dehydration, tachycardia, possible shock
91
Sepsis from a SBO leads to an ________ response that may result in remote organ failure.
immune
92
Gastritis
inflammatory disorder of the gastric mucosa
93
Acute Gastritis
erosion of the protective stomach mucosal barrier
94
What causes Acute Gastritis? (2)
Helicobacter pylori and NSAIDs
95
NSAIDs
a drug that inhibits prostaglandin synthesis
96
What do prostaglandins do?
stimulate goblet cells to secrete mucus
97
What does H. pylori do?
burrows into mucus layer and disrupts mucosal layer function while triggering an immune response
98
Gastritis symptoms:
-pain
-vomiting
99
How long does gastritis take to begin healing?
within a few days
100
Who does chronic gastritis occur in?
older adults
101
Chronic gastritis causes chronic ________ and mucosal _______
inflammation; atrophy
102
Chronic Non-Immune Gastritis = _______ gastritis
antral
103
Chronic Immune Gastritis = _____ gastritis
fundal (involves body and fundus)
104
What causes antral gastritis?
H. pylori
105
Antral gastritis involves high levels of ____ secretion that increases the risk for __________
HCl; duodenal ulcers
106
Fundal gastritis is caused by...
loss of T cell tolerance
107
What happens with Fundal gastritis?
loss of T cell tolerance causes gastric mucosa to be degenerated
108
What causes peptic ulcers? (2)
H. pylori and NSAIDs
109
Name the 3 types of peptic ulcers:
1. duodenal
2. gastric
3. stress-related mucosal disease
110
What are the most frequent type of peptic ulcer?
duodenal ulcers
111
How are duodenal ulcers formed?
causative factors that cause acid and pepsin to penetrate the mucosal barrier
112
How does the host respond to duodenal ulcers?
T and B cells, neutrophils combat H. pylori which release cytokines that damage the gastric epithelium
113
Does H. pylori release a toxin?
yes, it causes apoptosis in epithelial cells
114
How common are gastric ulcers to duodenal ulcers?
1/4 as common
115
Where do gastric ulcers form?
gastric antrum (next to acid producing gastric body)
116
What is the defect that causes gastric ulcers?
increased permeability of the mucosal barrier to H+
117
What does HCl do?
convert pepsinogen to pepsin
118
Mucosa damaged by H+ in gastric ulcer formation produces ________
histamine
119
What does histamine stimulate?
HCl (and thus pepsin) production
120
Stress-related mucosal disease is an _____ form of peptic ulcers
acute
121
What 3 things are often accompanied by stress related mucosal disease?
1. physiological stress
2. illness
3. major trauma
122
Where do ulcers from SRMD form?
multiple sites in stomach or duodenum
123
Ischemic Ulcers
develop within hours of events such as hemorrhage, heart failure, sepsis
124
Curling Ulcers
develop due to burn injury
125
Cushing Ulcers
develop due to brain trauma or surgery
126
The loss of the body's ability to discriminate harmful pathogens from commensal microorganisms can activate the ________ system which produces pro-inflammatory _________ which destroy the intestinal epithelium
immune; cytokines
127
Commensal
one organism benefits and the other neither benefits or is harmed
128
What are the 3 inflammatory bowel diseases?
1. ulcerative colitis
2. Chron's disease
3. Irritable bowel syndrome
129
What is ulcerative colitis?
a chronic inflammatory disease that causes ulcers in the colonic mucosa
130
Where does ulcerative colitis begin? Where does it spread to?
begins in rectum and may extend to entire colon
131
With ulcerative colitis, small erosions turn into ulcers by means of _______
necrosis
132
With ulcerative colitis, which layer of the GI tract thickens to narrow the lumen, reducing transit time?
muscularis mucosa
133
Symptoms of ulcerative colitis:
-bleeding
-urge to defecate
-watery diarrhea (10-20/day) with blood and mucus
134
Are the symptoms of ulcerative colitis persistent?
no, there are periods of remission (bettering) and exacerbation (worsening)
135
How are ulcerative colitis and Chron's disease diagnosed?
endoscopy and biopsies
136
How are ulcerative colitis and Chron's disease treated?
-steroids
-medication
-surgery (severe cases)
137
What causes Chron's disease?
unknown, it is an idiopathic disease
138
What part of the digestive tract does Chron's disease affect?
anywhere from mouth to anus
139
With Chron's disease, where does the inflammation begin?
intestinal submucosa
140
Chron's disease either spreads _____________ or __________
discontinuous or transmural
141
Discontinuous Spread
"skip lesions" or discontinuous/patchy inflammation
142
Transmural Spread
across the entire wall of an organ (full length of bowel wall)
143
Where is the most common site of Chron's disease?
ascending and transverse colon
144
Chron's disease ulcers can produce _______ (fistulae) that extend the inflammation into the _________ tissue
fissures; lymphoid
145
_________ increases risk for severe Chron's disease and a poor response to treatment
smoking
146
Fistulae
an abnormal opening or passage between two organs
147
With CD, where do fistulae form? (4)
1. peri-anal area
2. bladder
3. rectum
4. vagina
148
What is Irritable Bowel Syndrome (IBS)?
abdominal pain with altered bowel habits (alternating constipation and diarrhea)
149
What causes IBS?
unknown (idiopathic), no biomarkers for disease
150
Evidence leans toward altered gut ________ causing IBS
microflora (normal gut bacteria)
151
IBS is ___-___x more common in _____ with a higher prevalence in youth and middle age.
1.5-3x; women
152
IBS Symptoms
-lower abdominal pain
-discomfort
-bloating
153
IBS symptoms are usually relieved with __________
defecation
154
Does IBS interfere with sleep?
no
155
Is there a cure for IBS?
no
156
IBS treatment is ____________
individualized
157
What is appendicitis?
inflammation of the appendix
158
What does the appendix supposedly do?
lymphoid tissue body that is a "safe house" for commensal bacteria that repopulate the intestinal system
159
What is the most common surgical emergency of the abdomen?
appendicitis
160
Appendicitis usually occurs at age ____-____ but can occur at any age or not at all.
10-19 years
161
Symptoms of Appendicitis
-mild pain that increases to intense pain in a span of 3-4 hours
-nausea
-vomiting
162
How is appendicitis treated?
laparoscopic appendectomy
163
A hypothesis for the cause of appendicitis indicates that it becomes _________, which blocks drainage, increases pressure, and reduces blood flow causing it to become _________.
obstructed; hypoxic
164
Hypoxic appendix tissue turns into an ______ that promotes _________ invasion triggering an immune and inflammatory response.
ulcer; bacterial
165
Bacterial invasion of the appendix ulcer causes _________ to develop
gangrene
166
What are the four main disorders of the liver? (Hint: h______ e______, j_________, c________, viral h________)
1. hepatic encephalitis
2. jaundice
3. cirrhosis
4. viral hepatitis
167
Encephalopathy
brain disease that alters brain structure or function
168
What is hepatic encephalopathy?
a complex neurological syndrome that begins in the liver and is characterized by impaired behavioural, cognitive, motor function
169
What do biochemical alterations alter in hepatic encephalitis?
neurotransmission and brain function
170
Hepatic encephalitis results from a liver dysfunction where collateral vessels _______ blood around the liver into ________ circulation
shunt; systemic
171
Shunting hepatic blood into the systemic circulation allows _________ absorbed by the GI tract (usually for removal) to travel to the _______.
toxins; brain
172
What do toxins do to the brain? (3)
-alter energy metabolism
-interfere with neurotransmission
-cause edema
173
How does ammonia contribute to hepatic encephalitis?
it causes astrocytes to swell which alter the BBB and promote cerebral edema
174
What is another name for jaundice?
Icterus
175
What is jaundice?
yellowing pigmentation of the skin
176
What causes jaundice?
hyperbilirubinemia (↑ plasma bilirubin)
177
Bilirubin is a component of ___________ breakdown
hemoglobin (Hb)
178
Bilirubin is a waste product that is normally removed by the _______, thus jaundice indicates damage to this organ.
liver
179
Jaundice is characterized as either __________ or __________
obstructive or hemolytic
180
Obstructive Jaundice occurs when the ________________ becomes occluded by gall stones or a tumour
common bile duct
181
Obstructive jaundice results in bilirubin entering the blood stream after it is accumulated in the liver because it can't flow to the _________
duodenum
182
Hemolytic jaundice occurs when large bilirubin amounts are produced from excessive ___________
hemolysis of RBCs
183
Darkened ________ will be noticeable several days before the onset of jaundice
urine
184
Jaundice development poses risk for ________ infections
bacterial
185
Which part of the skin yellows first?
the sclera of the eye
186
What is cirrhosis?
the irreversible fibrotic scarring of the liver in response to inflammation and tissue damage
187
What step is cirrhosis in the process of chronic liver diseases?
final step
188
The physiological hallmark of cirrhosis is the development of...
scar tissue
189
Cirrhosis obstructs _______ flow, producing ________, portal ____________, and cellular _________
blood; jaundice; hypertension; dysfunction
190
What disrupts liver regeneration after cirrhosis has occurred that leads to liver failure?
hypoxia (lead to necrosis, atrophy, then liver failure)
191
Cirrhosis is manifested by is _________ appearance and _______ texture upon palpation
cobbly; hard
192
What are the 3 types of cirrhosis?
1. alcoholic
2. non-alcoholic fatty liver disease
3. biliary
193
Alcoholic cirrhosis occurs due to the toxic effects of alcohol or _______ alterations
immune
194
What is alcohol transformed into that activates hepatic stellate cells?
acetaldehyde
195
Hyper activation of stellate cells forms _________ that leads to fibrosis and scarring
collagen
196
Damage via alcoholic cirrhosis results in gut microbiota being _____________
translocated (movement)
197
Non-alcoholic fatty liver disease is characterized by an infiltration of hepatocytes with __________
triglycerides
198
Non-alcoholic fatty liver disease is associated with ________
obesity (high blood triglyceride and cholesterol levels)
199
Damage due to biliary cirrhosis begins in the ___________ rather than hepatocytes
bile ducts
200
Primary Biliary Cirrhosis is caused by...
chronic autoimmune liver disease (T cell and anti-mitochondrial antibodies)
201
Damage to the bile ducts by fibrosis from primary biliary cirrhosis leads to a bile duct ___________
obstruction
202
What causes secondary biliary cirrhosis?
obstruction of common bile duct via gallstones or tumours
203
What is viral hepatitis?
a common systemic disease that primarily affects the liver
204
How many types of hepatitis are there?
5 - A, B, C, D, E
205
What can all types of hepatitis cause?
jaundice
206
Hepatitis pathogens cause hepatic cell _________ and scarring
necrosis
207
What promotes further injury with hepatitis?
the immune response
208
What types of hepatitis are the most severe in terms of damage?
B (B has vaccine) and C (C has no vaccine)
209
Why does a co-infection of Hepatitis and HIV occur?
the virus' share the same transmission route
210
How is hepatitis spread?
body fluids
211
Co-infection of HIV and Hep causes a rapid ___________
progression of the disease
212
How is hepatitis diagnosed?
presence of viral antibodies
213
How is hepatitis treated?
viral replication suppression drugs
214
___________ and ___________ are common gallbladder disorders
obstruction and inflammation
215
What are gallstones?
aggregates of bile that block the flow of bile in/out and lead to gallbladder inflammation
216
What is Cholelithasis?
gallstone formation
217
What is Cholecystitis?
gallbladder inflammation
218
What causes a pancreatic obstruction?
backup of pancreatic secretions
219
Pancreatic obstruction causes the release and activation of pancreatic ________ within ______ cells
enzymes; acinar
220
What is the result of enzyme release in the pancreas?
auto-digestion of cells and tissues that cause inflammation
221
Autodigestion causes ______ damage, n________, and _________ formation
vascular; necrosis; pseudocyst
222
Pseudocyst
walled off collections of pancreatic secretions
223
______ is the main cause of further pancreatic obstruction
alcohol
224
When acinar cells metabolize ethanol it creates...
toxic metabolites that release acinar digestive enzymes
225
Chronic alcohol effects destroy acinar cells and destroy tissue that is replaced with ________
fibrosis (scarring)
226
Scarring in the pancreas leads to pancreatic ______
cysts
227
How is pancreatic obstruction via alcohol treated?
alcohol cessation
228
Cancer of the esophagus can be ________ or _______________
carcinoma or adenocarcinoma
229
Where are adenocarcinomas initiated?
epithelial glandular cells
230
Where are carcinomas initiated?
epithelial squamous cells
231
Esophageal cancer causes _______ and _____ pain
dysphagia and chest pain
232
__________ combined with smoking or _______ tobacco increase risk for esophageal cancer
Alcohol; chewing
233
Gastric (stomach) cancer is associated with _________ and _____ or preserved foods
H. pylori; salty
234
How does salt contribute to gastric cancer?
enhances conversion of nitrates into carcinogenic nitrosamines
235
Pre-existing _____ are highly associated with colon ______________
polyps; adenocarcinomas
236
Colon and rectal cancer manifest as: (3)
-pain
-bloody stool
-change in bowel habits
237
Where can rectal carcinomas close to the anus spread to?
vagina or prostate
238
Cancer of the ______ accounts for the leading cause of worldwide cancer deaths
liver
239
Primary liver cancers are associated with chronic liver diseased caused by ______ or hep __
cirrhosis or hep B
240
Where do hepatocellular carcinomas arise from?
hepatocytes
241
Where do cholangiocellular carcinomas originate?
bile ducts
242
Cholangiocellular carcinomas are _____
rare
243
What ages are gallbladder cancers most common?
age 50-60
244
Is carcinoma or adenocarcinoma more common in the gallbladder?
adenocarcinoma
245
Where do gallbladder cancers metastasize to?
lymph vessels
246
Pancreatic cancer is the ______ leading cause of cancer death in Canada
fourth
247
___________ occurs in the ______ (gland type) part of the pancreas
adenocarcinomas; exocrine
