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ESA 3 - Gastrointestinal System > Intestines > Flashcards

Flashcards in Intestines Deck (278):
1

Into where does the stomach empty chyme?

The duodenum

2

What happens to chyme in the duodenum? 

It is conditioned 

3

What features of chyme are modified in conditioning? 

  • Acidic
  • Hypertonic
  • Partly digested

4

How is the acidity of chyme modified in conditioning? 

It is corrected by HCO3-

5

Where does the HCO3- used to correct the acidic nature of chyme in conditioning come from? 

Secreted from the pancreas, liver, and duodenal mucosa 

6

When is the HCO3- used to correct the acidity of chyme in conditioning produced? 

During the production of gastric acid 

7

How is hypertonicity of chyme modified in conditioning? 

Corrected by the osmotic movement of water into the duodenum across its wall 

8

How is the partly digested nature of chyme modified in conditioning? 

Digestion is completed by enzymes

9

Where do the enzymes used to finish digestion of chyme in conditioning come from? 

The pancreas and duodenal mucosa 

10

Other than enzymes, what is required from the completion of digestion of chyme in conditioning? 

Bile acids from the liver

11

What conditions does absorption require? 

A large surface area, to which the luminal contents of the small intestine needs to be exposed to through gentle agitation for hours 

12

How is the surface area of the small intestine maximised? 

  • Very long
  • Increased by millions of villi projecting into the lumen

13

How do epithelial cells (enterocytes) arise? 

By rapid division in the crypts between the villi, and migration towards the tips

14

What happens to enterocytes at the tips of the villi? 

They are shed 

15

What happens to newly formed enterocytes as they migrate to the tip? 

They mature 

16

What covers the luminal surface of the enterocytes? 

Microvilli 

17

What is the purpose of the microvilli present on the enterocytes? 

  • Further increase surface area 
  • Form the brush border

18

What does the brush border form? 

An 'unstirred layer'

19

What happens at the unstirred layer? 

Nutrients meet and react with enzymes secreted by the enterocytes, completing digestion prior to absorption

20

Label this diagram

  • A - Muscle layers 
  • B - Villi 
  • C - Hepatic portal vein 
  • D - Lumen 
  • E - Capillary bed 
  • F - Lacteal 
  • G - Microvilli
  • H - Villi 

21

What is the function of the large intestines? 

Absorb water from the indigestible residues of chyme

22

What do the large intestines do to the indigestible residues of chyme? 

Convert them into semi-solid stool or faeces 

23

What happens to the faeces formed by the large intestines? 

It is stored temporarily and allowed to accumulate until defecation occurs 

24

What are teniae coli? 

The thickened bands of smooth muscle of the large intestines 

25

What do the teniae coli constitute? 

Most of the longitudinal coat of the large intestines 

26

Where do the teniae coli run? 

The length of the large intestine

27

What is the effect of the teniae coli on the part of the wall they are associated with? 

They shorten it 

28

Why do the teniae coli shorten the part of the wall they are associated with? 

Because of their tonic contraction

29

What does the shortening of the wall due to teniae coli form? 

Haustra

30

What are haustra? 

Where the colon becomes sacculated, or 'baggy', between the teniae

31

Label this diagram

  • A - Right colic (hepatic) flexure
  • B - Transverse colon 
  • C - Superior mesenteric artery
  • D - Haustrum 
  • E - Ascending colon
  • F - Ileum 
  • G - Ileocecal valve
  • H - Cecum
  • I - Vermiform appendix
  • J - Rectum 
  • K - Anal canal 
  • L - External anal sphincter 
  • M - Sigmoid colon
  • N - Tenia coli 
  • O - Cut edge of mesentery
  • P - Descending colon 
  • Q - Epiploic appendages
  • R - Transverse mesocolon
  •  S - Left colic (splenic) flexure

32

What are the sections of the small intestine? 

  • Duodenum 
  • Jejenum
  • Ileum

33

What functions are common between all sections of the small intestine? 

  • Secrete protease and carbohydrase enzymes to complete digestion
  • Secrete hormones

34

What hormones are secreted by all sections of the small intestine? 

  • Secretin 
  • Gastrin
  • Cholecystokinin

35

What are the functions of the duodenum? 

  • Addition of bile and pancreatic secretions 
  • Secretes HCO3to neutralise chyme
  • Osmotic movement of water into the duodenum, making chyme more hypotonic
  • Absorption

36

Where in the duodenum are bile and pancreatic secretions added? 

Ampulla of Vater

37

What is absorbed in the duodenum?

Iron

38

What are the functions of the jejunum? 

  • Absorption
  • Uptake of things small enough to soak through the villi

39

What is absorbed in the jejenum? 

  • Carbohydrates 
  • Amino acids

40

What substances are small enough to soak through the villi? 

  • Fatty acids 
  • Vitamins
  • Minerals 
  • Electrolytes 
  • Water

41

What is the function of the ileum? 

Absorption

42

What is absorbed by the ileum? 

  • Vitamin B12
  • Bile
  • Anything not absorbed by the jejenum

43

Label this diagram

  • A - Duodenum
  • B - Ileocecal junction
  • C - Cecum 
  • D - Appendix
  • E - Duodenojejunal junction

 

  1. Jejunum
  2. Ileum 

44

How long does the large intestine take to finish the digestion of food? 

About 16 hours 

45

What are the functions of the large intestine? 

  • Absorption
  • Sends indigestible matter to the rectum

46

What does the large intestine absorb? 

  • Water
  • Any remaining absorbable nutrients 
  • Vitamins created by colonic bacteria

47

What vitamins are created by colonic bacteria? 

  • Vitamin K 
  • B12
  • Thiamine
  • Riboflavin

48

What is the function of the rectum? 

Stores and compacts faecal matter

49

In what form are carbohydrates ingested in the small intestime? 

In the form of amyloses, amylopectins, or dissacharides such as sucrose 

50

What is the structure of amylose? 

Straight chain with α-1,4 bonds 

51

What is the structure of amylopectin? 

Branched, with α-1,6 bonds at branches 

52

What do α-amylases act on? 

α-1,4 bonds

53

Where are α-amylases secreted? 

  • In saliva
  • By pancreas

54

What do α-amylases yield? 

  • Glucose and maltose from amyloses 
  • α-limit dextrins from amylopectins 

55

What completes the breakdown of glucose? 

Brush border enzymes

56

What enzymes are found in the brush border? 

  • Isomaltase
  • Maltase
  • Sucrase
  • Lactase

57

What does isomaltase do? 

Breaks down branched molecules at α-1,6 bonds

58

What does maltase do? 

Converts maltose to glucose 

59

What does sucrase do? 

Converts sucrose to glucose and fructose diamer 

60

What does lactase do? 

Converts lactose to glucose and galactose diamer 

61

Where does the energy from the active absorption of glucose come from? 

The Nagradient set up by Na/K/ATPase in the basolateral membrane

62

Where does glucose enter the epithelial cell? 

Across its apical membrane 

63

What transport is required to move glucose across the epithelial apical membrane? 

Na+/Glucose Symporter, SGLT1

64

Other than glucose, what does SGLT1 transport? 

Galactose

65

Where does glucose leave the epithelial cell into the bloodstream? 

Across the basolateral membrane 

66

How does glucose leave the epithelial cell across the basolateral membrane? 

Via facilitated diffusion through the GLUT2 transporter 

67

How does fructose enter the epithelial cell from the lumen? 

Via facilitated diffusion 

68

What are proteins digested to? 

Oligopeptides 

69

What is an oligopeptide? 

Short peptides, 10-20 AA's long

70

Where are proteins first digested? 

In the stomach

71

What digests proteins in the stomach? 

Pepsin 

72

What secretes pepsin in the stomach?

Chief cells

73

What enzymes digest proteins in the duodenum? 

Peptidases

74

What secretes the peptidases in the duodenum? 

The pancreas

75

How do different peptidases vary? 

They 'prefer' breaking different bonds 

76

What peptidases are present in the duodenum? 

  • Pepsin
  • Trypsin
  • Chymotrypsin
  • Carboxypeptidase

77

What bonds does pepsin prefer to break? 

Bonds near aromatic AA side chains 

78

What bonds does trypsin prefer to break? 

Bonds near basic AA side chains 

79

What bonds does chymotrypsin prefer to break? 

Bonds near aromatic AA side chains 

80

What bonds does carboxypeptidase prefer to break? 

C-terminal AA's with basic side chains 

81

In what form can proteins be absorbed by the small intestine? 

Both amino acids and small peptides (2/3 AA's)

82

How does absorption of proteins by the small intestine differ in neonates? 

In neonates, the gut is 'open', so in addition to amino acids and small proteins, they are able to pick up whole proteins 

83

What is the clinical importance of the 'open' gut in neonates? 

It allows breast milk to confer passive immunity on babies via IgA absorption

84

What transporter is required for the active uptake of amino acids? 

Na+/Amino acid co-transporters

85

How many types of Na+/Amino acid co-transporters are there? 

At least 5 

86

How do Na+/Amino acid transporters get the energy required for the active uptake of amino acids? 

Using the Na+ gradient set up by Na/K/ATPase

87

Give 5 types of Na+/Amino acid co-transporters

Those that take up - 

  • Small, neutral AA's
  • Neutral AA's, basic AA's, and cysteine
  • Acidic AA's
  • Imuno-AA's
  • ß AA's (mainly taurine)

88

What facilitates some AA uptake? 

Passive diffusion

89

How are dipeptides and tripeptides taken up? 

By an active mechanism associated with pumping H+ into the lumen, which then returns by co-transport with the peptide 

90

What is the result of fats being relatively insoluble in water? 

They tend to aggregate into large globules 

91

What is the result of fats tending to aggregate into large globules? 

It prevents effective action of digestive enzymes 

92

What excerbates the aggregation of fat into large globules? 

Acid in the stomach 

93

What happens to fats in the duodenum? 

They are incorporated into micelles

94

What allows fats to be incorporated into micelles in the duodenum? 

Bile acids 

95

How big are the micelles formed by fats and bile acids in the duodenum? 

4-6nm 

96

Describe the structure of the fat micelles formed in the duodenum? 

Fats in the middle and polar components of bile acids on the outside 

97

What is the function of the fat micelles? 

  • Generate a high surface area for the action of lipases 
  • Carry products into the 'unstirred layer' 

98

What is the effect of lipases on the fat micelles?

They cleave the fatty acids from glycerol 

99

Where is the 'unstirred layer' located? 

Immediately next to the mucosa 

100

What happens to micelles in the unstirred layer? 

Fatty acids can be released to slowly diffuse into the epithelial cells 

101

What happens to the fatty acids from micelles once inside epithelial cells? 

They are reconstituted into triacylglycerols and re-expelled as chylomicrons 

102

What are chylomicrons? 

Structured small particles

103

What are chylomicrons made up of? 

Lipids covered in phospholipids 

104

What do chylomicrons do? 

Facilitate the transport of fat in the lymphatic system from the gut to systemic veins 

105

How is sodium taken up by the small intestine? 

Via diffusion into the cell, and actively transported across the basolateral membrane by Na-K-ATPase

106

What is the importance of sodium uptake by the small intestine? 

It provides the driving force for the majority of absorption 

107

What ion follows the movement of Na+?

Chloride 

108

What does the movement of Naand Cl-, coupled with all of absorption, give? 

An osmotic gradient 

109

What does the osmotic gradient in the small intestine do? 

Leads to the uptake of water 

110

What minerals are taken up by the small intestine? 

  • Calcium 
  • Iron 
  • Vitamins

111

How much calcium is absorbed from the small intestine each day, compared to how much is consumed? 

700mg/day absorbed out of 6g consumed - >10% 

112

How does Ca2+ enter the epithelial cell? 

Facilitated diffusion

113

What allows Ca2+ to be taken up into the small intestinal epithelial cell by facilitated diffusion? 

There is a low intracellular concentration 

114

How is Ca2+ pumped out of the basolateral membrane? 

By Ca2+-ATPase

115

What does both the facilitated diffusion of calcium and transport through the basolateral membrane require? 

Vitamin D 

116

What is the uptake of calcium by the small intestine stimulated by? 

Parathyroid hormone (PTH)

117

How much iron is consumed per day? 

20mg

118

What constitutes most of the iron consumed? 

Haem

119

In what form can iron be absorbed? 

Only its ferrous form (Fe2+)

120

How is iron made into its ferrous form? 

Gastric acid solubises iron complexes, making them ferrous 

121

What happens to ferrous iron once it has been formed in the stomach? 

Gastroferrin binds iron and keeps it ferrous 

122

What secretes gastroferrin? 

The stomach 

123

What secretes transferrin? 

Intestinal mucosal cells

124

What does transferrin do?

Finds ferrous ions in the lumen

125

What happens once transferrin has found ferrous iron in the lumen? 

The complex is taken into cells by endocytosis, spplit, and the iron is exported to the blood

126

What happens once the iron split from transferrin is exported to the blood? 

It binds again to transferrin 

127

How are water-soluble vitamins absorbed in the small intestine? 

Via passive diffusion 

128

What vitamins are water soluble? 

  • Vitamin C
  • B vitamins 

129

What is vitamin B12 absorbed with? 

A co-factor 

130

Where is vitamin B12 absorbed? 

In the terminal ileum only

131

When does the intrinsic factor bind to vitamin B12?

In the stomach

132

What is the purpose of the intrinsic factor binding to vitamin B12

To keep in soluble 

133

What secretes the intrinsic factor that binds to vitamin B12

The stomach mucosa 

134

What occurs with vitamin B12 deficiency? 

Pernicious anaemia 

135

What causes pernicious anaemia? 

Damage to the stomach, preventing it from secreting the intrinsic factor, or when the terminal ileum has been damaged or removed 

136

When may the terminal ileum be damaged? 

Crohn's 

137

How is the uptake of Narelated to the uptake of water? 

It generates an osmotic gradient, which water follows 

138

What does glucose uptake do? 

  • Stimulates Nauptake 
  • Generates its own osmotic gradient 

139

What will stimulate maximum water uptake? 

A mixture of glucose and NaCl 

140

What is the mixture of glucose and NaCl known as? 

Oral rehydration fluid 

141

What must happen to the intestinal contents for effective absorption? 

It must move very slowly (transit time in hours), whilst being gently agitated 

142

How is the slow movement and agitation of intestinal contents achieved? 

By a pattern of motility called segmenting 

143

Are segmenting and perilstalsis the same thing? 

No, they are very different 

144

How is the small intestine divided? 

Into sections 

145

What does each section of the small intestine have? 

A pacemaker 

146

How does the frequency of the pacemaker change through the small intestine? 

It gets less from the duodenum to the terminal ileum (12 times a minute to 8) 

147

What is the decrease in pacemaker frequency phenomenom known as? 

The intestinal gradient 

148

What does each pacemaker drive? 

A small section of intestine 

149

What does the pacemaker driving of the section of small intestine cause? 

Intermitted contraction of the smooth muscle along its length

150

What is the result of the intermittent smooth muscle contraction caused by the pacemaker? 

It seperates the intestine into segments where the muscle is not contracted 

151

What happens to the intestinal contents at each segment? 

It is effectively mixed by movement from the portions that do contract 

152

What happens after a few seconds of contraction of a segment? 

The contractions relax, and the next pacemaker fires to make different areas contract 

153

What is the purpose of segmenting? 

Mixes the contents of the intestine 

Segmenting itself does not proper contents

154

What does the intestinal gradient result in? 

In terms of movement

There is a net movement, albeit slow, in a caudal direction 

155

What is the large intestine naturally divided into? 

Segments known as Haustra 

156

How are Haustra formed? 

The circular muscles are more complete than the longitudinal, which have been reduced to taenia coli

157

Describe the structure of taenia coli

  • Thick circular muscle 
  • Thin longitudinal muscle
  • Only 3 layers 

158

What is the effect of contraction of hte smooth muscle in the walls of the Haustra? 

It shuffles the contents back and forth

159

What happens as the intestinal contents is being shuffled back and forth by the Haustra? 

There is slow absorption of the remaining water and salts, forming faeces

160

Where does the intestinal contents progress too from the Haustra? 

The sigmoid colon

161

How is Haustral shuffling controlled? 

Segmenting like control 

162

What happens in mass movement of the colon? 

Once or twice a day, there is a perilstaltic propelling pattern from the transverse through to the descending colon 

163

What is the result of mass movement? 

It forces faeces rapidly into the rectum

164

What happens when faeces is forced into the rectum? 

It induces the urge to defecate 

165

Why does faeces being forced into the rectum induce the urge to defecate? 

Because the rectum is normally empty 

166

What is mass movement often triggered by? 

The gastro-colic reflex, triggered by eating 

167

Does mass movement occur at certain times of the day? 

Often does, because people 'like to be regular' 

168

How many anal sphincters are there? 

Two, internal and external 

169

What kind of muscle is present in the internal anal sphincters? 

Smooth 

170

What control is the internal anal sphincter under? 

Parasympathetic 

171

What happens to the internal anal sphincter when it recieves parasymphathetic stimulation? 

It relaxes

172

What kind of muscle is present in the external anal sphincter? 

Voluntary striated muscle 

173

What control is the external anal sphincter under? 

Voluntary (normally)

174

What happens once both anal sphincrers are relaxed? 

Intra-abdominal pressure is increased, forcing expiration

175

What is the result of the increase in intra-abdominal pressure caused by the relaxation of the internal and external anal sphincters? 

There is an expulsion of faeces 

176

When is the voluntary control of the external sphincter overriden? 

If rectal pressure becomes too high 

177

What are the types of inflammatory bowel disease? 

  • Ulcerative colitis 
  • Crohn's disease 
  • Diversion Colitis 
  • Diverticular colitis 
  • Radiation 
  • Drugs
  • Infections
  • Ischaemic colitis 

178

What is ulcerative colitis? 

An inflammatory disorder 

179

Where does ulcerative colitis affect? 

The rectum, and extends proximally in continuity to affect a variable extent of the colon

180

What is meant by UC extending in continuity? 

There are no breaks in the inflammation 

181

Where is there a high incidence of UC? 

  • US, UK and northen Europe
  • Young adults
    • More commonly in females

182

What is the mucosa of UC patients dominated by? 

Th2 (T-helper) cells 

183

What do Th2 cells produce? 

  • Transforming Growth Factor (TGF)
  • IL-5

184

How does ulcerative colitis present? 

  • Rectal bleeding
  • Diarrheoa 
  • Abdominal pain 

185

Where does extensive colitis affect? 

Entire colon and rectum 

186

What is extensive colitis also known as? 

Pancolitis or total colitis 

187

What is affected in distal colitis? 

  • Rectum
  • Sigmod colon
  • Descending colon

188

What is affected in proctitis? 

Rectum only

189

What is Crohn's disease? 

A condition of chronic inflammation

190

Where does Crohn's Disease affect? 

Potentially any location of the GI tract from mouth to anus 

191

When does CD have the highest incidence? 

Two peaks- 

  • 15-30 years
  • 60 years

192

What is the mucosa of CD patients dominated by? 

Th1 (T-helper) cells 

193

What do Th1 cells produce? 

  • Interferon Gamma (IFN-γ) 
  • IL2

194

What does the presentation of CD depend on? 

The diseases location

195

What is the presentation of CD with upper GI involvement?

  • Nausea and vomiting
  • Dyspepsia
  • Small bowel obstruction
  • Anorexia
  • Weight loss
  • Loose stools

196

What is the presentation of CD when its a colonic disease? 

  • Diarrhoea
  • Passage of obvious blood

197

What may occur when there is termianal ileum involvement in CD? 

Anaemia

198

Why may terminal ileum involvement in CD cause anaemia? 

Because of poor absorption of vitamin B12

199

What causes inflammatory bowel disease? 

  • May have genetic predisposition 
  • Environmental factors 

200

What genes may give genetic predisposition to inflammatory bowel disease? 

  • IBD1
  • NOD2/CARD15

201

By how much does having one copy of a risk allele increase the risk of Crohns? 

2-4x

202

By how much does having two copies of a risk allele increase the risk of Crohn's? 

20-40x 

203

What environmental factors may increase the risk of inflammatory bowel disease? 

  • NSAIDs
  • Early appendectomy 
  • Smoking

204

Why does NSAIDs increase the risk of IBD? 

May be the altered intestinal barrier

205

What is an early appendectomy linked to? 

Increased UC incidence

206

What is the effect of smoking on the risk of IBD? 

  • Protects against UC
  • Increases risk of CD

207

What are the triggers for inflammatory bowel disease? 

  • Antibiotics
  • Diet
  • Acute infections 
  • NSAIDs
  • Smoking
  • Stress

208

How deep is the inflammation in UC?

Mucosal 

209

How deep is the inflammation in CD? 

Transmural 

210

What is the difference in the pattern of disease between UC and CD? 

In UC it is continuous. In CD, it may skip area 

211

What is the location of UC? 

Colorectum 

212

What is the location of CD? 

Mouth to anus 

213

Is there rectal involvement in UC? 

Usually 

214

Is there rectal involvement in CD? 

Can be, but less common than in UC 

215

What kind of ileal disease is sometimes present with UC? 

Backwash ileitis 

216

What % of UC patients also have backwash ileitis? 

15-20%

217

Does Crohn's disease present with ileal disease? 

Yes, it is common

218

Does UC cause fistulas? 

Rarely

219

Does CD cause fistulas? 

Commonly

220

Does UC cause perianal disease? 

Rarely

221

Does CD cause perianal disease? 

Commonly

222

Does UC cause granulomas? 

Unlikely

223

Does CD cause granulomas? 

Yes, in 50-60% of patients 

224

Does UC cause overt bleeding? 

It is unusual

225

Does CD cause overt bleeding? 

It is less common

226

Does UC cause malnutrition? 

It is unlikely

227

Does CD cause malnutrition? 

It is more common

228

What cancer risk does UC confer? 

Colorectal cancer 

229

What cancer risk does CD confer? 

Colorectal cancer or small bowel cancer, depending on location

230

What will be seen on a radiograph in UC? 

Collar button ulcers

231

What will be seen on a radiograph in CD? 

String sign of Kantor

232

What methods are commonly used for investigating inflammatory bowel disease? 

  • Colonoscopy
  • Stool analysis 
  • Barium radiographs
  • CT scan
  • Capsule endoscopy
  • Plain X-ray

233

How is a colonoscopy used to investigate IBD? 

  • Biopsies of involved mucosa
  • Ulceration

234

What will be looked for in stool analysis? 

  • Parasites 
  • Clostridium difficile toxin

235

How is a stool analysis conducted? 

Using a culture 

236

When will a plain X-ray be used to investigate IBD? 

If bowel obstruction or perforation suspected 

237

What is this image showing? 

Crohn's disease

238

What macroscopic changes will be seen in CD? 

  • Involved bowel usually thickened, often narrowed
  • Deep ulcers and fissures in mucosa may produce cobblestone apperance
  • Fistulae and abscesses may be seen

239

What does the presence of fistulae and abscesses in CD reflect? 

Penetrating disease 

240

What macroscopic changes will be seen with UC? 

  • Mucosa looks reddened, inflamed and bleeds easily
  • In severe disease, there is extensive ulceration with the adjacent mucosa appearing as inflammatory (pseudo) polyps

241

What microscopic changes will be seen with CD? 

  • Inflammation through all layers of the bowel (transmural)
  • Increase in chronic inflammatory cells
  • Lymphoid hyperplasia 
  • Granulomas

242

Why can you see granulomas microscopically with CD? 

THresponse 

243

What microscopic changes will be seen with UC? 

  • Superficial inflamamtion 
  • Chronic inflammatory cells infiltrate in the lamina propria 
  • Crypt abscesses 
  • Goblet cell depletion 

244

How can differentation be made between UC and CD? 

  • Clinical data
  • Radiological data
  • Histological differences in rectal and colonic mucosa

245

How are samples of rectal and colonic mucosa obtained? 

By biopsy 

246

When may it not be possible to distinguish between UC and CD? 

If the biopsies are obtained in the acute phase 

247

What are patients considered to have when their disease cannot be distinguished between CD and UC? 

Colitis of Undetermined Type and aEtiology (CUTE)

248

What may be of value when determining between CD and UC? 

Serological testing for anti-neutrophil cytoplasmic antibodies (ANCA) in UC, and anti-Saccharomyces cervisiae antibodies (ASCA) in CD 

249

What may be required to make an exact diagnosis sometimes? 

Examination of a surgical colectomy specimen 

250

When is a colonscopy performed with CD? 

If colonic involvement is suspected 

251

What will be seen on a colonscopy with CD? 

Mild, patchy surface ulceration to cobblestoning 

252

When is an upper GI endoscopy required with CD? 

To exclude oesophageal and gastroduodenal disease in patients with relevant symptoms 

253

When is small bowel imaging mandatory? 

In patients with suspected Crohn's 

254

How is small bowel imaging conducted? 

  • Barium follow through 
  • CT scan with oral contrast 
  • Small bowel ultrasound
  • MRI 

255

What will be seen in small bowel imaging in a patient with CD? 

  • Asymmetrical alteration in the mucosal pattern with deep ulceration, and areas of narrowing or structuring
  • String sign of Kantor 

256

When is a perianal MRI or endoanal ultrasound used in patients with CD? 

To evaluate perianal disease

257

When is a capsule endoscopy used in Crohn's disease patients? 

When they have a normal radiological examination 

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What is the 'gold standard' investigation for the diagnosis of UC? 

Colonscopy with biopsy

259

What is a colonscopy used for in UC? 

To assess the disease activity and extent 

260

Why is a plain abdominal X-ray used in UC? 

To exclude colonic dilation 

261

Why are other imaging techniques rarely used in UC? 

As endoscopy is preferred 

262

What is often seen on imaging with UC patients? 

Collar Button Ulcers 

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What are Collar Button Ulcers? 

Ulcer through the bowel mucosa to the muscle, then up and down in a 'T' shape

264

What treatment options are available for CD? 

  • Induction of remission 
  • Maintenance of remission
  • Treatment of perianal disease 
  • Surgical management 

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How is remission induced in CD patients? 

  • Oral or IV glucocorticosteroids 
  • Enteral nutrition 
  • Anti-TNF antibodies 

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What is the name of the anti-TNF antibodies given in CD? 

Infliximab

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How is remission maintained in CD? 

  • Methotrexate 
  • Azathioprine
  • Anti-TNF antibodies 

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How is perianal disease treated?

  • Ciprofloxacin and Metrronidazole
  • Azathioprine
  • Anti-TNF antibodies

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How do anti-TNF antibodies treat CD? 

They bind to membrane bound TNF-α and induce immune cell apoptosis

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When is surgical management required for CD? 

  • Failure of therapy with acute or chronic symptoms 
  • Complications 
  • Failure to grow in children, despite children

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What complications of CD may necessitate surgical management? 

  • Dilation
  • Obstruction
  • Perforation
  • Abscesses

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What surgical management may be performed in patients with CD?

  • Colectomy
  • Ileorectal anastomosis

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What is used to treat distal UC (proctitis)?

Topical or suppository corticosteroids

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What is used to treat left sided UC?

Topical corticosteroid enema

276

What is used to treat extensive UC? 

  • Oral corticosteroids 
  • Infliximab

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When is surgical management required in patients with UC? 

  • Patients with complications 
  • Patients with corticosteroids dependence

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What is the favoured surgical management in patients with acute UC? 

Subtotal colectomy with end ileostomy and preservation of the rectum