Case 11 Flashcards
(362 cards)
1
Q
Arterial supply of caecum
A
Superior mesenteric artery
Branches into ileocolic artery
Branches into right and left caecal arteries
2
Q
Pain course in Appendicitis
A
Initially, vague pain in periumbilical region due to stretching of visceral peritoneum.
Then severe pain in right lower quadrant due to irritation of parietal peritoneum
3
Q
Phrenicolic ligament
A
Attaches transverse colon to diaphragm
4
Q
Omental appendices
A
Small pouches of peritoneum on the surface of the colon, filled with fat
5
Q
Teniae Coli
A
3 strips of muscle on surface of the bowel wall.
Contract to shorten the bowel
(Mesocolic, free, omental)
6
Q
Haustra
A
Sacculations in bowel wall caused by contraction of teniae coli
7
Q
Components of solids found in rectum
A
Cellulose/Epithelial cells
Bacteria
Salts
Stercobilin
8
Q
Gaseous components found in rectum
A
Indol and Skatol
9
Q
Production of gases found in rectum
A
Indol and Skatol produced by breakdown of amines by bacteria
10
Q
Pouch of Douglas is also known as
A
Rectouterine pouch
11
Q
Anorectal ring
A
Fusion of internal and external anal sphincters, and puborectalis muscle
12
Q
Epithelium lining anal canal and rectum
A
Columnar
13
Q
Epithelium lining anal canal below pectinate line
A
Non keratinised stratified squamous
14
Q
Vascular supply above pectinate line in anal canal
A
Superior rectal artery and vein
15
Q
Vascular supply below pectinate line in anal canal
A
Inferior rectal artery and vein
16
Q
Nerve supply above pectinate line in anal canal
Sensitive to…
A
Hypogastric plexus
Sensitive to stretch
17
Q
Nerve supply below pectinate line in anal canal
Sensitive to…
A
Inferior anal nerves
Sensitive to pain, temperature, touch and pressure
18
Q
Non pathological haemorrhoids
A
Vascular cushions found within anal canal.
Help to maintain faecal continence
19
Q
Type of muscle in Internal Anal Sphincter
A
Smooth (involuntary, controlled by autonomic NS)
20
Q
Type of muscle in External Anal Sphincter
A
Skeletal
21
Q
Nerve supply to External Anal Sphincter
A
Pudendal Nerve
22
Q
Process of Defaecation
A
Contraction of external anal sphincter and puborectalis muscle
Increases anorectal angle and compresses anal canal
23
Q
Main site of sodium reabsorption in the GI tract
A
Jejunum
24
Q
Main site of potassium reabsorption in the GI tract
A
Jejunum (and ileum)
25
How is potassium reabsorbed into the jejunum?
Solvent drag i.e. by the flow of water, not through specific ion channels
26
Site of potassium secretion into GI tract
Colon
27
Regulator of potassium secretion into GI tract
Aldosterone
28
Main site of calcium reabsorption in the GI tract
Duodenum
29
How is calcium reabsorbed into the GI tract?
TRPV channels (Transient Receptor Potential Vallinoid)
30
Hormone regulator of calcium uptake in the GI tract
Calcitrol
31
Intracellular buffer required for calcium uptake in the GI tract
Calbindin
32
Transferrin
Glyco-protein found in blood which binds to iron and tranports it
33
High ferritin suggests
Iron storage problem - haemochromatosis, or chronic disease process
34
Low ferritin suggests
Iron deficiency causing anaemia
35
Low transferrin causes
anaemia
36
Ferritin
Intracellular protein which stores iron
37
Role of Enteric (NANC) neurons in regulation of secretion/absorption in the GI tract
Release VIP - Chloride ion secretion
38
Role of Enterochromaffin cells in regulation of secretion/absorption in the GI tract
Release serotonin - Chloride ion secretion
39
Role of D cells in regulation of absorption/secretion in the GI tract
Release somatostatin - chloride and sodium ion absorption
40
Actions of Somatostatin
Inhibits G cells (inhibits secretion of gastrin)
| Stimulates sodium and chloride ion absorption
41
Role of enteric neurons in regulation of absorption/secretion
Release encephalins - chloride and sodium ion absorption
42
NANC neurons
Non adrenergic, non cholinergic neurons
43
Role of luminal bacteria on regulation of secretion/absorption in the GI tract
Release enterotoxins (e.g. cholera toxin) - chloride ion reabsorption
44
Role of mast cells in regulation of secretion/absorption in the GI tract
Release histamine - chloride ion absorption
45
Effect of aldosterone on secretion/absorption in the GI tract
Sodium ion and water reabsorption in the GI tract
46
Verner Morrison Syndrome
Increased VIP
Increased Cl- secretion into GI tract
Draws water into lumen
Watery diarrhoea
47
Why do SSRIs (e.g. Prozac) cause diarrhoea?
Increased availability of serotonin
Increased Cl- secretion into GI tract
Draws water into lumen
48
Excitatory neurotransmitters in enteric nervous system
ACh and Substance P
49
Inhibitory neurotransmitters in enteric nervous system
VIP and Nitric Oxide
50
Intestinal wall contractions after a meal (Postprandial)
Shortening/Lengthening of individual villi
Segmentation mixing via circular smooth muscle
Pendular mixing via longitudinal smooth muscle
Peristaltic waves (transports contents approx 5cm)
51
Migrating Motility Complexes
Once/hour during fasting, contents is moved over a long distance (0.5m) due to MOTILIN released by M cells
Flushing of the intestines
52
Peristaltic Reflex
Stretch receptors in submucosal plexus activated due to bolus in lumen.
Relaxation of intestinal wall ahead of bolus.
Contraction of intestinal behind bolus
53
SIP syncytium
Smooth Muscle cells
Interstitial cells of cajal
PDGFR-alpa+
54
Interstitial cells of Cajal
Show pacemaker activity due to cyclic release of Ca2+ from stores
55
Motilin released from... in response to...
Released from M cells in the duodenum in response to fat and acid
56
Neurotensin released from... in response to...
N cells in ileum in response to fat
57
Effect of Neurotensin on intestinal epithelial cells
Decreases motility
58
Effect of motilin
Stimulates gastric emptying
59
Enteroglucan released from... in response to ...
L cells in the distal ileum in response to glucose and fat
60
Effect of enteroglucan
Decreases motility
61
Effect of VIP on intestinal smooth muscle cells
Relaxation
62
Effect of encephalins on intestinal motility
Stimulates Peristaltic reflex
63
Hirschsprung's disease
Aganglionic congenital megacolon
Part of GI tract have no ganglion cells so cannot function - MEGACOLON
Muscle remains contracted.
Distention of area of colon proximal to affedted area
64
Why is Cl- exchanged for HCO3- in colon?
Bicarbonate neutralises acidity produced by bacterial symbiotic flora
65
Factors affecting mass movement in the colon
Parasympathetic intrinsic reflex pathways (vagal neurons)
Gastrin
CCK
66
Immune function of Greater Omentum
Forms adhesions near an inflamed organ (e.g. appendix), enclosing it off to protect other organs
67
Epiploic foramen
Connects greater and lesser sacs of peritoneum
68
Clinical presentation of Pneumoperitoneum
Abnormal presence of gas in peritoneum.
Affected diaphragm (C3,4,5)
Therefore, referred pain in tip of shoulder
69
Vertebral level of coeliac trunk
T12
70
Left gastric artery supplies
Oesophagus and lesser curvature
71
Splenic artery supplies
Spleen and part of pancreas
72
Common hepatic artery supplies
Proximal duodenum
Liver
Gallbladder
73
Vertebral level of Superior Mesenteric Artery
L1
74
Inferior Pancreaticoduodenal artery supplies
Duodenum and Pancreas
75
Right colic artery supplies
Ascending colon
76
Middle colic artery supplies
Proximal 2/3 of transverse colon
77
Vertebral level of Inferior Mesenteric Artery
L3
78
Left colic artery supplies
Distal 1/3 of transverse colon
| Descending colon
79
Ligament of Treitz
Attaches duodenojejunal flexure posterior to abdominal wall
80
Surface anatomy: Where are the small intestines located?
Epigastric and umbilical region
81
Surface anatomy: Where is the ileocaecal junction located?
Right Iliac Fossa
82
Jejunum has a .... diameter than ileum
Greater
83
Ileum has a .... wall than jejunum
Thinner
84
Plicae circularis
Circular folds/large valvular flaps
Project into the lumen of the small intestine
(more in jejunum than ileum)
Continue across entire circumference of bowel
85
Jejunum has (long/short) vasa recta and (few/many) arcades
Long
| Few
86
Ileum has (long/short) vasa recta and (few/many) arcades
Short
| Many
87
Symptoms of intussusception
Pain
Distension
Constipation
Absent bowel sounds
88
Meckel's Diverticulum
Congenital
Slight bulge in small intestine
Remnant of yolk sac
89
Normal diameter of caecum
9cm
90
McBurney's Place
Appendicular orifice used in surgical excision of appendix
1/3 of the distance from Right ASIS to the umbilicus
91
Normal diameter of colon
6cm
92
What are diverticula?
Mucosa extruding through weakened muscular wall of colon
93
Cause of diverticulitis
Faeces obstructing neck of diverticula causing accumulation of bacteria
94
Diverticulitis normally affects
Sigmoid colon
95
Symptoms of diverticulitis
```
Pain/Tenderness/Guarding in Left Iliac Fossa
Palpable mass
Fever
Constipation
Tachycardia
```
96
Complications of diverticulitis
Bowel perforation
Abscess formation
Fistulae into adjacent organs
Generalised peritonitis
97
Lymphatic drainage of rectum/anal canal above pectinate line
Internal iliac nodes
98
Lymphatic drainage of anal canal below pectinate line
Superficial inguinal canal
99
Why are internal haemorrhoids painless?
Supplied by Hypogastric plexus which only responds to stretch
100
Why are external haemorrhoids acutely painful?
Supplied by inferior anal nerves
| Respond to pain, temperature, touch and pressure
101
Indirect inguinal hernia
Lateral to inferior epigastric vessels
102
Direct inguinal hernia
Medial to inferior epigastric vessels
103
Young boy with inguinal hernia descending into the scrotum
Indirect
104
Elderly man with inguinal hernia, palpable in abdominal wall above pubic tubercle
Direct
105
Nerves involved in sympathetic innervation of GI tract
Splancnhnic Nerves
106
Spinal level of foregut
T5-T9
107
Spinal level of midgut
T10-T12
108
Spinal level of hindgut
L1/2
109
Splanchnic nerve supplying foregut
Greater
110
Splanchnic nerve supplying midgut
Lesser
111
Splanchnic nerve supplying hindgut
Lumbar
112
Area of referred pain from foregut
Epigastric region (below nipples, above umbilicus)
113
Area of referred pain from midgut
Umbilical region
114
Area of referred pain from hindgut
Left and right flanks
| Lateral and anterior thighs
115
Adenomas are
neopastic polyps
116
Polyps are
Precursors for carcinoma
117
Adenomas in the intestine arise from
Glandular epithelium
118
Ulcerative colitis
Diffuse mucosal inflammation, limited to the colon
119
Symptoms of Ulcerative colitis
RECTAL BLEEDING
Diarrhoea
Urgency
Abdominal pain
120
UC almost always affects
Rectum (Proctitis)
121
Crohn's Disease
Patchy, transmural inflammation affecting any part of the GI tract (Mouth to anus)
122
Crohn's Disease commonly affects...
Large bowel and terminal ileum
123
Toxic megacolon is an acute complication of...
Ulcerative colitis
124
How does Ulcerative colitis cause toxic megacolon?
Ulcerating inflammatory processes dissect into the wall of the colon
125
What is seen on a radiograph of toxic megacolon?
Early - accumulation of gas over a segment of the colon. Scalloped edge due to oedema and spasm.
Late - dilatation (maximal in transverse colon), abnormal haustra and thumb-printing
126
Thumb-printing
Caused by inflammation e.g. UC, Crohn's Disease, Pseudomembranous colitis, ischaemic colitis
127
Contraindicated procedures in Toxic Megacolon
Barium enema
| Colonoscopy
128
Early sign on radiograph of bowel perforation
Subserosal dissection of luminal gas into bowel wall
| i.e. gas from the bowel invades the bowel wall
129
Inflammation in Crohn's disease usually occurs where?
Ileocaecal region (75-80%)
130
Symptoms of inflammation in Crohn's disease
```
Right lower quadrant pain
Tenderness
Low grade fever
Anorexia and weight loss
Diarrhoea
```
131
How does an obstruction occur in Crohn's disease? (4)
Fibromuscular proliferation and deposition of collagen in bowel wall (narrowing of lumen)
Inflammatory infiltration
Fibrosis (above)
Spasm
Oedema
132
Symptoms of obstruction in Crohn's disease
```
Post-prandial cramps
Distention
Borborgymi (noisy bowel sounds)
Vomiting (due to high grade obstruction)
Weight loss
```
133
Symptoms of enteroenteric fistulisation
Usually asymptomatic
134
Symptoms of Enterovesical fistulisation
UTIs
| Pneumoturia (air in urine)
135
Symptoms of retroperitoneal fistulisation
Psoas abscess signs
| e.g. pain in back, hip or knee and a limp
136
Symptoms of enterocutaneous fistulisation
Drainage via a scar on the skin
137
Symptoms of perianal fistulisation
Pain, drainage
138
Symptoms of rectovaginal fistulisation
Drainage of faeces/air through vagina
139
Treatment of perianal fistulae
Seton - stitch to hold open fistula, allowing its contents to drain out rather than becoming infected.
140
'String-sign'
String-like appearance of a contrast filled bowel due to severe narrowing of lumen
141
Why would 'string-sign' be seen in inflammation in Crohn's Disease?
Narrowing of lumen due to transmural thickening and irritative spasm
142
Red flags for IBD
```
Anaemia
Weight loss
Fever
Perianal disease
Occult blood/Faecal WBCs
```
143
Effect on IBD risk of smoking
Decreases risk of UC
| Increases risk of CD
144
Effect on IBD of appendicectomy
Protects against UC
| No effect on CD
145
MOA of mesalazine
5-ASA is the active moiety
Diminishes inflammation of bowel by blocking COX
Reduces prostaglandin production
146
5 Aminosalicylic Acid drugs
Mesalazine
Balsalazine
Olsalazine
147
What is the problem with sulfalazine treatment?
When cleaved it forms 5ASA and sulphapyridine
| Sulphapyridine is clinically toxic when circulating
148
Indication for mesalazine
Mild to moderate Ulcerative colitis (active and in maintaining remission)
Crohn's Disease
149
Indication for prednisolone
Severe active UC or CD
150
MOA of prednisolone
Glucocorticoid analogue
Binds to steroid receptor acting as a transcription regulator.
Increased anti inflammatory proteins
Decreased inflammatory immune factors
151
Route of administration of prednisolone
Oral
152
Route of administration of hydrocortisone
IV
153
ADRs of prednisolone
Cushing's
Weight gain
Immunosuppression
154
Contraindications of prednisolone
Cushing's
Immunosuppressed
Active infection
155
MOA of Budesonide
Glucocorticoid analogue
Binds to steroid receptor acting as a transcription regulator.
Increased anti inflammatory proteins
Decreased inflammatory immune factors
156
Why is budesonide used in ulcerative colitis?
Corticosteroid - reduces inflammation
Controlled ileal release (a common site of inflammation in UC)
157
Immunosuppressant used in UC
Cyclosporin
158
Immunosuppressant used in CD
Methotrexate
159
MOA of Azathioprine
Immunosuppressant
Active metabolite interferes with nucleic acid synthesis in WBCs (especially T cells)
Reduces production of inflammatory mediators by WBCs
160
Antibiotics used for Crohn's disease
Metronidazole
| Ciprofloxacin
161
MOA of Metronidazole
Antibiotic
| Inhibits nucleic acid synthesis in
162
MOA of ciprofloxacin
Antibiotic
| Inhibitor of topoisomerase II/DNA gyrase
163
MOA of Infliximab
Anti-TNF drug
| Competitive inhibitor of TNF alpha receptor
164
Benefits of Kock pouch over Brooke Ileostomy
Faecal continence maintained
| No external appliance
165
Ileal-pouch Anal Anastomoses
Formation of a new rectum surgically
Will always have watery stools
Faecal continence maintained
166
Drug therapy for mild/moderate active disease in UC
Mesalazine
167
Drug therapy for severe active disease in UC
Corticosteroids
| Anti-TNF therapy
168
Drug therapy in maintaining remission in UC
Mesalazine
| Azothioprine (Immunosuppressant)
169
Drug therapy in moderate active disease in CD
Budesonide (Corticosteroid)
Dietary therapy
Antibiotics
170
Drug therapy in severe active disease in CD
Corticosteroids
| Anti TNF drugs
171
Drug therapy in maintaining remission in CD
Azathioprine (Immunosuppressant)
| Anti TNF drugs
172
Brunner's Glands
Submucosal glands which secrete alkaline mucus-like fluid into duodenal lumen
173
Peyer's Patches
Aggregates of lymphocytes in wall of jejunum/ileum
174
Coeliac Disease
Inflammation of upper small bowel mucosa which improves when gluten is withdrawn from the diet
175
Clinical features of Coeliac Disease
```
Steatorrhoea/Diarrhoea
Abdominal Pain
Ulcers/Algular stomatitis
Flatulence
Weight loss
```
176
Why do coeliac patients get steatorrhoea?
Duodenal cells cannot signal for CCK release
No contraction of gallbladder
Reduces fat digestion and absorption
177
Why do coeliac patients get flatulence?
Fermentation of undigested food by gut flora
178
Why are coeliac patients at risk of osteomalacia?
Low calcium absorption
179
Findings in colonoscopy of coeliac patient
Erythematous, inflamed, scalloped lining of upper GI tract
180
Site of absorption of B12
Terminal ileum
181
Pseudopolyp
Piece of mucosa, where the surrounding mucosa has eroded from around it.
182
Bacteria commonly associated with gastroenteritis in the UK
Campylobacter Jejuni
| Salmonella
183
Indication of C.Diff infection on colonoscopy
Yellow plaques
184
Treatment of C. Diff
Metronidazole
185
Erythema Nodosum
Red lumps on skin of shins (and sometimes thighs and forearms)
Associated with IBD
186
Apthous Stomatitis
Non contagious, benign mouth ulcers
| Associated with IBD
187
Episcleritis
Inflammation of episclera - between sclera and conjunctiva
| Associated with IBD
188
Anterior Uveitis
Inflammation of iris and ciliary body
| Associated with IBD
189
Pyoderma Gangrenosum
Painful ulcers, usually on legs
| Associated with IBD
190
Central arthropathy in IBD associated with which genotype
HLA B27
191
Central arthropathy seen in IBD
Ankylosing spondylitis
| Sacroiliitis
192
Features of liver disease associated with IBD
Primary sclerosing cholangitis
Steatosis - fatty liver
Chronic hepatitis
Cirrhosis
193
Extraintestinal manifestations in IBD which are unrelated to disease activity:
Central arthropathy
| Liver disease
194
Transmission of Clostridium Difficile
.Person to Person
| Faeco oral
195
Who is at high risk of contracting clostridium difficile?
Elderly
Hospitalised
On antibiotics (destory gut flora)
196
Clinical manifestation of Clostridium difficile infection
Colitis - diarrhoea, abdo pain, anorexia
Increased WCC
Reduced renal function
Fever
197
Management of Clostridium difficile
Nutrition and fluid balance
Metronidazole
Infection control
FMT - faecal microbiological transplantation
198
Transmissionof Campylobacter
Ingestion of contaminated food (usually chicken)
199
Management of campylobacter
Self-limiting, does not normally require Abx
| Erythromycin may shorten duration of symptoms
200
Clinical manifestation of campylobacter infection
Small bowel - Diarrhoea, N+V, Fever, Cramping
201
Transmission of salmonella
Ingestion of poorly cooked/contaminated food (chicken + eggs)
202
Clinical manifestation of salmonella
```
Diarrhoea
N+V
Headache
Cramps
Fever
```
203
Incubation period for campylobacter
1-7 days
204
Symptoms of campylobacter last
2-7 days
205
Incubation period for salmonella
8-48 hours
206
Symptoms of salmonella last
48-96 hours
207
Why is salmonella infection a public health issue?
Takes 9 weeks for an infected individual to become culture negative.
potential to infect others during that time
208
Non GI manifestations of salmonella
Osteolmyelitis (bone infection)
Focal infections e.g. of prosthetic joints
Meningitis
209
Management of salmonella infection
Normally no antibiotics
In severe cases:
Quinolones
Macrolides
Cephalosporins
210
MOA of fluoroquinolones
Topoisomerase II inhibitor
211
MOA of macrolides
Protein synthesis inhibitor - prevents translocation
212
MOA of cephalosporins
Inhibit cell wall synthesis (Beta lactams)
213
Transmission of E. Coli
Ingestion of contaminated food
214
Management of E. Coli
Supportive
Isolation
Ciprofloxacin if severe
215
MOA of ciprofloxacin
Fluoroquinolone
| DNA gyrase inhibitor
216
Transmission of cholera
Faecally contaminated food/water
217
Clinical manifestation of cholera
Watery diarrhoea
218
Management of cholera
aggressive rehydration (Rehydration solution, Oral rehydration salts)
219
Transmission of Shigella
Faeco-oral
220
Management of Shigella
Rehydration
| Ciprofloxacin if severe
221
Clinical manifestation of Shigella Dysenteriae
Diarrhoea - small amount containing blood and mucus
Abdominal cramps
Fever
222
Incubation period for shigella
12 hours to 6 days
223
Symptoms of shigella last
3-7 days
224
Clinical manifestation of norovirus
Small bowel affected
Fever
Vomiting
Diarrhoea
225
Incubation period for norovirus
24-48 hours
226
Antibiotic treatment for C.Diff
Metronidazole or vancomycin
| Causative Abx should be continued if possible
227
Antibiotic treatment for Campylobacter
Azithromycin
228
Antibiotic treatment for Salmonella
Ciprofloxacin
229
Antibiotic treatment for E.Coli (VTEC)
Avoid - Increases risk of Haemolytic Uraemic Syndrome by release of toxin from bacteria
HUS can lead to renal damage or death
230
Antibiotic treatment for Giardia (Lamblia)
Metronidazole
231
Transmission of Giardia(Lamblia)
Contaminated water
232
Symptoms of Giardia (Lamblia)
Diarrhoea - bulk, offensive smelling, pale
Abdo bloating
Anorexia
Nausea
233
Transmission of Cytospordium
Contaminated water
234
Cytospordium particularly affectes...
Immunocompromised - associated with AIDS and low CD4
235
Clinical manifestation of Cytospordium
Small intestine
| Diarrhoea, abdo cramps, weight loss
236
Clinical manifestation of Cytospordium in px with AIDS
Small intestine
Diarrhoea, abdo cramps, weight loss
PLUS Cholangitis and cholecystitis
237
Management of cytospordium
None with immunocompetent
Immunocompromised patients - HAART
238
Management of Entamoeba Histolytica
Metronidazole
| Luminal amoebacide
239
Treatment of cyclospora
Usually self limiting
| Can be given cotrimoxazole
240
CCDA agar plate used for
Campylobacter
241
SMAC agar plate used for
E.Coli
242
XLD agar plate used for
Salmonella
| Shigella
243
TCBS agar plate used for
Vibrio Cholera
244
Lynch syndrome increases risk of
Cancers (inc. colorectal)
245
Gene mutations causing adenomatous colorectal polyps
APC
| MYH-AP
246
Gene mutations in Lynch syndrome
MSH-2, MLH-1
247
Inheritance pattern of FAP
Autosomal dominant
248
Gene mutation in FAP
APC
249
Inheritance pattern of MYH-Associated Polyposis
Autosomal recessive
250
Regions of bowel most commonly affected by colorectal cancer
21% sigmoid colon
| 38% rectum
251
'Signet ring' cells
Where mucin produced by adenocarcinoma displaces cell nucleus to side of cell.
Poor prognosis
252
Symptoms of colorectal cancer
```
Change in bowel habit
Tenesmus
Rectal bleeding
palpable mass
Symptoms of anaemia (due to GI bleeding)
```
253
Location of APC gene
5q21
254
Role of APC gene
Tumour suppressor
255
K-ras
Protein which regulates cell division.
Mutated in 30-50% of colorectal cancers
Allows adenoma to become adenocarcinoma
256
SMAD2 and SMAD4
Intracellular proteins which mediate TGF-beta - Therefore regulating transcription, apoptosis and differentiation.
May be lost in colorectal cancer
257
Role of p53 in formation of cancer from adenoma
Coordinates response to DNA damage, oxidative stres and aberrant proliferative signals
258
Dukes' classification of colorectal cancer - A
Tumor confined to mucosa
259
Dukes' classification of colorectal cancer - B1
Tumor growth into muscularis propria
260
Dukes' classification of colorectal cancer - B2
Tumor growth into muscularis propria and serosa (full thickeness)
261
Dukes' classification of colorectal cancer - C1
Tumor spread to 1-4 lymph nodes
262
Dukes' classification of colorectal cancer - C2
Tumor spread to >4 lymph nodes
263
Dukes' classification of colorectal cancer - D
Distant metastases (liver, lung, bone)
264
Premalignant lesions for colorectal cancer in Lynch Syndrome patients
MMR (mismatch repair) deficient crypts
265
PD-1 inhibitors/blockade
Activate immune system to attack tumors.
| Used in tumours with mismatch repair deficiency
266
Management of Lynch Syndrome
Aspirin (600mg/day)
Vaccines - Micoryx and Monocyte derived dendritic cells
PD-1 blockade
267
5-FU Response
S phase arrest
p53 accumulation
Upregulation of p53 target genes
Apoptosis
268
Small bowel is positioned...
centrally
269
Diameter of small bowel
3cm
270
Ileus
Bowel stops peristalsis
| Causes abnormal bowel dilatation despite no mechanical blockage
271
Intususception
One part of bowel invaginates into another part of bowel
272
Volvulus
Loop of intestine twists around itself and the mesentary
Closed loop obstruction in large bowel.
273
Pneumatosis Intestinalis
Intramural gas in bowel wall due to gaseous cysts
| will eventually perforate
274
What does pneumatosis intestinalis look like on AXR?
Gas tracks in intestinal wall (black line outlining lumen)
275
Rigler's Sign
Triangle-shaped pockets of gas in peritoneal cavity
| Suggestive of bowel perforation
276
Why is an erect CXR useful in detecting perforation?
Gas rises up above liver - black line over liver, under diaphragm
277
Falciform sign
Occurs in bowel perforation when gas rises up either side of the falciform ligament
Can be seen on a supine abdominal X Ray
278
Football sign on a AXR suggests
Bowel perforation - gas rises up in a circular fashion
279
Barium follow through in Crohn's patient shows:
Rose thorn ulcers (spikes on outer surface)
Stricturing
Thumb printing
280
When is oral contrast indicated in imaging of the bowel?
Suspected Acute inflammation
281
When is Portal Venous IV contrast indicated in imaging of the bowel?
```
Suspected:
Obstruction
Perforation
Ischaemic bowel
Acute inflammation
Acute GI bleed
```
282
After IV contrast is administered, non enhancing bowel suggests...
Ischaemia - since contrast was not able to reach that area
283
What is the significance of carrying out CT scan of the patient prone and supine?
Normal bowel contents will move when the patient changes from supine to prone.
A polyp or other lesion will not.
284
Indication for Colonoscopy
Colonic symptoms
Suspected cancer/colitis
Ideally <40yrs
285
Indication for minimum prep CT
Colonc symptoms
| >80yrs
286
Indication for CT Pneumocolon (Virtual colonoscopy)
40-80yrs (outside age for colonoscopy)
Suspected extracolonic cancer
Failed colonoscopy
287
T1 MRI
Fat = white
Water = black
Good for anatomy
288
T2 MRI
Fat = black
Water = white
Good for pathology
289
When is a chest X Ray indicated in abdominal pathology?
Perforation suspected - pneumoperitoneum
290
Vertebral level of kidneys
T12-L3
291
Benefits of ingestion of plant sterols and stanols
Reduce total blood cholesterol
292
Marasmus
Undernourishment causing weight to be significantly lower than expected (variable loss of muscle and fat)
Metabolism is normal
Seen in anorexia nervosa
293
Cause of Kwashiokor
Deficiency in dietary protein
294
Mechanism for kwashiorkor
Reduces intracellular glutathione/GSH
Peroxidation of cell membranes
Membranes become leaky
Fluid moves from blood into interstitium due to high osmotic pressure
295
Sources of vitamin A
Dairy
Fish
Meat (liver)
296
Function of vitamin A
Colour vision
| Antioxidant
297
Deficiency of vitamin A
Keratosis (permanent goosebumps)
Xeropthalmia (dry, inflamed conjunctive)
Poor night vision
298
Sources of vitamin D
Eggs
Liver
Fish oil
299
Role of sunlight in vitamin D pathway
Converts 7-dehydrocholesterol into vitamin D
300
Function of vitamin D
Increases absorption of calcium in the GI tract
301
Deficiency of vitamin D
Rickets/Osteomalacia
302
Parathyroid hormone is released when...
Plasma calcium falls
303
Function of PTH
To increase plasma calcium by:
Increased absorption from GI tract
Increased reabsorption in kidney tubules
Increased release from bone
304
Source of vitamin E
Spinach
Almonds
Sunflower seeds
305
Function of vitamin E
Antioxidant - protects against atherosclerosis
| reduces risk of stroke and MI
306
Vitamin E deficiency
Haemolytic anaemias
307
Sources of vitamin K
Green leafy vegetables
| Liver
308
Function of vitamin K
Clotting factor synthesis (Prothrombin, VII, IX, X)
309
Vitamin K deficiency
Bruising/Bleeding
310
Sources of vitamin B1 (thiamine)
```
Lean meat
Fish
Eggs
Legumes
Green vegetables
```
311
Vitamin B1 is also known as ..
Thiamine
312
Function of vitamin B1/Thiamine
Involved in carbohydrate metabolism - a coenzyme in the link reaction
313
Deficiency of vitamin B1/Thiamine
Beri beri
314
Wet Beri beri
```
Affects cardiovascular system:
Tachycardia
Dyspnoea
Oedema
Raised JVP
```
Due to thiamine deficiency
315
Dry Beri beri
```
Affects peripheral nervous system:
Loss of reflexes
Loss of muscle function
Tingling or loss of sensation
Confusion
```
316
Sources of vitamin B2/Riboflavin
```
Milk
Liver
Kidneys
Heart
Meat
Green vegetables
```
317
Function of vitamin B2/Riboflavin
Component of FAD - involved in hydrogen transfer in oxidative phosphorylation
318
Deficiency of vitamin B2/riboflavin
Dermatitis
Angular Chelitis
Glossitis
Hypersensitivity to light
319
Sources of vitamin B3/niacin
Most foods (rare deficiency)
320
Function of vitamin B3/niacin
Component of NAD - involved in hydrogen transfer in oxidative phosphorylation
321
Deficiency of vitamin B3/niacin
Pellagra - diarrhoea, dermatitis, dementia, death
322
Deficiency of vitamin B5/Pantothenic acid
Neuropathy
| Abdominal pain
323
Deficiency of B6
```
Irritability
Convulsions
Anaemia
Vomiting
Skin lesions
```
324
Who is at risk of B7 (Biotin) deficiency?
```
Alcoholics
Px on antacids
Px with partial gastrectomy
Pregnant women
lactating womn
```
325
Sources of vitamin B9 (Folic acid)
Liver
Green vegetables
(Also synthesised by intestinal bacteria)
326
Function of vitamin B9/Folate
Haematopoiesis
Nucleic acid synthesis
Development of neural tube
327
Deficiency of B9/Folate
Anaemia
| GI disturbance and diarrhoea
328
Folic Acid (Vitamin B9) supplementation is recommended for....
Women trying to conceive
| Women during their first 12 weeks of pregnancy
329
Vitamin B12 (Cobalamin) deficiency
Pernicious anaemia
Loss of muscle power
Spinal nerve demyelination
330
Function of Vitamin B12/Cobalamin
Red blood cell production
Amino acid metabolism
CNS function
331
Function of vitamin C
Collagen synthesis
Redox reactions
Antioxidant
332
Deficiency of vitamin C
Scurvy - increased risk of infection, poor wound healing, anaemia
333
Vitamin C is also known as...
Ascorbic acid
334
Function of iron
Haemoglobin synthesis
| Electron transport
335
Iron deficency
Spooning of nails
Whitening of sclera
Anaemia
336
Zinc deficiency
Delayed puberty and small stature
Dermatitis
Alopecia
Poor wound healing
337
Magnesium deficiency
Muscle weakness
| Neuromuscular dysfuncion
338
Function of phosphorus
Bone mineralisation
339
Phosphorus deficiency
Rickets and osteomalacia
340
Iodine deficiency
Enlarged thyroid gland
341
Copper deficiency
Impaired mental development
Failure to keratinise hair
Skeletal and vascular problems
342
MOA of Mebeverine
Muscarinic ACh receptor antagonist
Prevents Calcium entry into cells
Therefore, antispasmodic
343
ADRs of Mebeverine
Constipation
Indigestion
Dry mouth
Dry skin
344
Contraindications of mebeverine
Paralytic ileus
345
MOA of loperamide
Mu-opioid receptor agonist
Reduces myenteric plexus activity
Reduces peristalsis
346
ADRs of Loperamide
Dizziness
Headache
Flatulence
Nausea
347
Contraindications of loperamide
Ulcerative colitis
| Bacterial Colitis
348
MOA of Cinchocaine
Blocks voltage gated sodium channels in nociceptive fibres
Prevents action potential propagation along axon to CNS
i.e. local anaesthetic
349
ADRs of cinchocaine
Bradyarrhythmias
CNS effects
Hypotension
350
Route of administration of antihaemorrhoidals
Topical application as a gel
| Rectal suppository
351
Local anaesthetic for haemorrhoids is combined with...
```
Anti inflammatory (NSAID or steroid)
Peripheral vasoconstrictor (e.g. phenylephrine)
```
352
Site of absorption of ethanol
Stomach
353
Site of absorption of calcium ions
Duodenum
Jejunum
Proximal ileum
354
Site of absorption of iron ions
Duodenum
Jejunum
Proximal ileum
355
Site of absorption of glucose (and other sugars)
Duodenum
Jejunum
Proximal ileum
356
Site of absorption of fatty acids
Duodenum
Jejunum
Proximal ileum
357
Site of absorption of vitamins
Duodenum
Jejunum
Proximal ileum
358
Site of absorption of Vitamin C
Proximal ileum
359
Site of absorption of Vitamin B12
Distal ileum
360
Site of absorption of Bile salts
Distal ileum
361
Cholesterol
Small bowel
362
Site of absorption of monovalent ions and water
Small and large bowel
