Gastrointestinal System Flashcards
1
Q
What are the functions of the gastrointestinal tract?
A
Mechanical disruption of food, temporary food store, chemical digestion and disruption, kill pathogens, absorption of nutrients, elimination of waste material.
2
Q
How is fluid balance maintained?
A
Somatic and autonomic neural control, histamine, hormones and vasoactive substances alter blood flow and acid secretion, enzymes produced for chemical digestion.
3
Q
What is saliva?
A
Hypotonic fluid containing water, mucus and solids such as enzymes, bacterial flora, antibodies and epithelial cells.
4
Q
What is the function of baseline saliva secretion?
A
Maintenance of hydration, reduces friction, prevents bacterial build up (halitosis) and maintenance of dental hygiene.
5
Q
Name the main salivary glands and the type of secretion they produce:
A
Sublingual- mixed secretions
Submandibular- mixed secretions, drains via Wharton’s duct
Parotid- serous secretions, drains via Stenson’s duct
6
Q
What are the functions of saliva?
A
Mineralisation, moistening and lubrication of food, taste perception, initiation of digestion, soft tissue repair, dilution and clearance of oral sugars, detoxification, buffering.
7
Q
Describe the secretory unit:
A
Isotonic saliva produced in the acinus of secretory cells, travels along secretory duct lined by intercalating cells, ions reabsorbed in striated duct so solution becomes hypotonic. Myoepithelial cells may aid contraction and secretion.
8
Q
What is swallowing/deglutition?
A
Series of orderly processes by which substances are passed from the mouth to the pharynx and then the oesophagus
9
Q
What may cause dysphagia?
A
Congenital abnormalities, stroke injury, hypertrophy of pharyngeal tonsils
10
Q
What are the oesophageal sphincters?
A
UOS- cricopharyngeus muscle
LOS- physiological sphincter at T10 level controlled by vagus nerve
11
Q
Oral phase of swallowing:
A
Voluntary control
Bolus formed and positioned at back of tongue
Reflex action pushes food back via receptors of palatoglossal arch
12
Q
Pharyngeal phase of swallowing:
A
Soft palate raises and closes opening between naso and oropharynx
Epiglottis is sealed
Tongue moves food into oesophagus
13
Q
Oesophageal phase of swallowing:
A
LOS relaxes
UOS constricts
Primary peristaltic wave is initiated, distension of oesophagus initiates a secondary wave if the first is insufficient
14
Q
What is a hiatus hernia?
A
Insufficient tightness of the diaphragmatic opening allows a part of the stomach to enter the thorax
15
Q
What is the peritoneal cavity?
A
Potential space between visceral and parietal peritoneum that contains a small amount of fluid.
16
Q
What is the structure of the primitive gut tube?
A
Foregut and hind gut are blind diverticula
Runs from the stomatodeum to the proctodeum
Opening to the yolk sac at the umbilicus
17
Q
What is the blood supply to the gut?
A
Foregut from the coeliac trunk
Midgut from the superior mesenteric artery
Hind gut from the inferior mesenteric artery
18
Q
What is the intraembryonic coelum?
A
Begins as one large cavity and is then subdivided by the future diaphragm
19
Q
What is a mesentery?
A
Double layer of peritoneum suspending the gut tube from the abdominal wall allowing conduit of blood and nerve supply, formed from condensation of the splanchnic mesoderm.
20
Q
What are the outcomes of the rotation of the stomach?
A
Greater and lesser curvature lie on the right and left hand side
Cardia and pyloric move horizontally pushing the greater curve inferiorly
Puts vagus nerves anterior and posterior
Moves the lesser sac behind the stomach
Creates greater omentum
21
Q
How does the foregut develop?
A
Respiratory diverticulum forms in ventral wall at junction with the pharyngeal gut placing the oesophagus dorsally
Liver, pancreas and biliary system are formed in the ventral mesentery (foregut association only)
Liver develops from hepatic bud, falciform ligament attaches to ventral body wall
Duodenal lumen is obliterated and recanalised
22
Q
What are the muscles of the abdominal wall (superficial to deep)?
A
Rectus abdominis
External oblique
Internal oblique
Transversus abdominis
23
Q
What is a hernia?
A
Protrusion of abdominal viscera into abdominal wall
24
Q
What is the difference between a direct and indirect inguinal hernia?
A
Direct hernia exits onto the wall via the weak area ‘Hesselbach’s triangle’
Indirect hernia follows the inguinal canal and passes through the deep inguinal ring
25
What are the borders of Hesselbach's triangle?
Epigastric vessels, inguinal ligament (base) and rectus abdominis (medially)
26
What is the path of the inguinal canal?
From the deep inguinal ring to the superficial inguinal ring, is the pathway from abdominal wall to external genitalia
27
What is meant by a Richter's hernia?
Inguinal or femoral, progresses more rapidly to gangrene but obstruction is less frequent and the entire lumen is not compromised
28
What is divarication of recti?
Midline lump that only appears on transition from sitting to standing, is common post-partum
29
What is the spigellian fascia?
Aponeurotic layer between rectus abdominis and linea semilunares
30
What is the difference between strangulation and incarceration?
Strangulation occurs when the blood supply is constricted by sweeping and congestion as to arrest its circulation
Incarceration means that the hernia cannot return to the abdominal cavity when pushed
31
How is a hernia repaired?
Obtain primary closure of muscle layer
Lichtenstein repair
Laparoscopic reinforcements
Use of specialised meshes
32
What is receptive relaxation?
The orad stomach allows entry of food without increasing intragastric pressure to prevent reflux
33
What is the blood supply to the stomach?
Lesser curvature- right gastric artery
Greater curvature- right and left gastroepiploic arteries
Duodenum- gastroduodenal artery
34
What cells are responsible for control of acid secretion and what are their functions?
Parietal cells produce HCl and intrinsic factor
G cells produce gastrin
Enterochromaffin like cells produce histamine
Chief cells produce pepsinogen
D cells produce somatostatin
Mucus cells produce mucus
35
What hormones increase H+ secretion?
Gastrin
Histamine
Acetylcholine (vagal stimulation)
36
How is acid secretion decreased?
Somatostatin release inhibits G cells (D cells stimulated by low pH when stomach empty)
Reduced vagal stimulation
37
What happens during the cephalic phase of digestion?
Preparatory- smelling, tasting, chewing
Direct stimulation of parietal cells by vagus nerve
Stimulation of G cells by vagus nerve via gastrin-releasing peptide
38
What happens in the gastric phase of digestion?
Distension of stomach stimulates vagus nerve
Amino acids and peptides stimulate G cells
Food acts as buffer and removes somatostatin inhibition by increasing pH
39
What happens in the intestinal phase of digestion?
Chyme initially stimulates gastrin
| Inhibition of G cells by somatostatin
40
What are the stomach's defences?
Mucus/bicarbonate layer adheres to epithelium (can be dissolved by alcohol)
High turnover of epithelial cells
Prostaglandins maintain mucosal blood flow (inhibited by NSAIDs)
41
What pharmacological treatments act on the stomach?
H2 blockers e.g. Ranitidine
| Proton pump inhibitors e.g. Omeprazole
42
What is the primary intestinal loop?
Elongation of the midgut forms a loop with the SMA as its axis, is connected to the yolk sac by the Vitelline duct
43
What is physiological herniation?
The cavity is too small in the 6th week to accommodate the midgut and the liver, so the midgut herniates into the proximal umbilical cord.
The cranial limb returns to the cavity first, and the Cecal bud descends to form the ascending colon
44
What is Meckel's diverticulum?
Approximately 2 feet from the ileocecal valve and can contain ectopic gastric/pancreatic tissue. Outpouching of a hollow structure, is the vestigial remnant of the omphalomesenteric (Vitelline) duct
45
What is pyloric stenosis?
Hypertrophy of the pylorus muscle not a failure of recanalisation
46
Where does recanalisation occur?
Oesophagus, bile duct and small intestine
47
What is gastroschisis and how does it differ from omphalcoele?
Gastroschisis is a failure of closure of the abdominal wall during folding of the embryo leaving the gut tube and its derivatives outside the body
Omphalcoele/exampholos is the persistence of physiological herniation and so has a covering of skin and subcutaneous tissue
48
What is the significance of the pectinate line?
Divides anal canal into two histologically distinct superior and inferior parts that have different arterial and nervous supply and venous and lymphatic drainage
49
What is the cloaca?
End of the hind gut separated into urogenital sinus and anorectal canal by the urorectal septum
50
What is the perineal body?
Where the urorectal septum fuses with the proctodeum (anal pit)
51
What is the arterial, venous and nervous supply above the pectinate line?
IMA
Pelvic parasympathetic innervation (S2-4)
Drains to internal iliac nodes
Only has stretch sensation
52
What are the features of the anus below the pectinate line?
Pudendal artery
Somatic pudendal nerves (S2-4)
Drainage to superficial inguinal nodes
Touch, temperature and pain sensitive
53
Where might gut pain be referred to?
Foregut produces epigastric pain
Midgut produces periumbilical pain
Hind gut produces suprapubic pain
54
What are the derivatives of the dorsal mesentery?
Greater omentum
Gastrolineal ligament from stomach to spleen
Leinorenal ligament from spleen to kidney
Mesocolon
Mesentery proper
55
What are the derivatives of the ventral mesentery?
Lesser omentum
| Falciform ligament
56
What is gastroesophageal reflux disease (GORD)?
Weakness of the lower oesophageal sphincter causing heartburn, cough, sore throat, dysphagia, raised intragastric pressure, hiatus hernia and Barrett's oesophagus (metaplasia)
57
What can cause acute gastritis?
NSAIDs
Alcohol
Chemotherapy
Bile reflux
58
What causes chronic gastritis?
Helicobacter pylori infection
Antibodies to parietal cells leading to pernicious anaemia
Chronic alcohol abuse
59
What is peptic ulcer disease?
Extends through muscular is mucosa, is most common in the first part of the duodenum and lesser curve of stomach
Can be caused by excess stomach acid, H. pylori and NSAIDs
Causes bleeding, anaemia, melina, haemetemis, weight loss
60
What are the features of Helicobacter pylori?
Faecal-oral transmission
Gram negative, helix shaped, microaerophilic
Produces urease that produces NH4+ ions to increase local pH
Flagellum allows adherence to epithelia
Releases cytotoxins that cause epithelial injury
Degrades mucus layer
Promotes inflammatory response
61
What is Zollinger-Ellison syndrome?
Non-beta islet cell gastrin secreting tumour of the pancreas that can be a part of multiple endocrine neoplasia causing proliferation of the parietal cells and increased H+ producing leading to severe ulceration of the stomach and small bowel
62
What can trigger stress ulceration?
Severe burns, raised intracranial pressure, sepsis, trauma, multi-organ failure
63
What is contained in the Porto hepatis?
Hepatic portal artery and vein
| Bile duct
64
What stimulates the pancreatic acinus to produce digestive enzymes?
Cholecystokinin (CCK)
65
Where is the sphincter of oddi located?
Second part of the duodenum, entry from pancreas
66
What secretions are produced by the pancreas?
```
Enzymes as zymogens including proteases, amylase and lipases
Bicarbonate ions (high flow rate increases secretion)
```
67
What are the functions of the liver?
```
Energy metabolism
Detoxification
Plasma protein production
Secretion of bile
Phagocytosis
Vitamin and mineral storage
```
68
What is the functional cell of the liver?
Hepatocytes
69
How is the liver structurally arranged?
Lobules with acini
Zones 1-3 getting closer to the central vein
Sinusoids connect the hepatic portal vein, artery and bile ducts to the central vein
70
What are the bile acid dependent parts of bile?
Bile acids and pigments secreted into canaliculi by hepatocytes
71
What are the bile acid independent constituents of bile?
Alkaline solution secreted by duct cells, stimulated by secretin
72
What is the function of bile salts and how does this relate to their structure?
Amphipathic in structure and act at oil/water interfaces and form micelles with fatty products that are crucial for emulsification
73
How are lipids absorbed?
Diffuse down concentration gradient then re-esterified and packaged with apoproteins into chylomicrons that enter lacteals
74
What is enterohepatic recirculation?
Bile salts remain in gut lumen and are reabsorbed in terminal ileum to return to liver where salts are extracted and recycled
75
What is the role of the gallbladder?
Stores and concentrates bile
76
What is steatorrhoea?
Bile acids or pancreatic Lipases insufficient so fat appears in faeces making them pale and float
77
Give examples of bile pigments:
Bilirubin (soluble due to conjugation)
| Haemoglobin converted to urobillinogen and then stercobillin
78
What are the GITs innate physical defences?
Sight, smell, memory, saliva, gastric acid, small intestinal secretions, colonic mucus, anaerobic environment, peristalsis
79
What constituents of saliva protect against toxins?
Lysozyme (affects gram positive)
Lactoperoxidase (gram negs)
Complement
IgA
80
What is xerostomia?
Severe illness/dehydration reducing salivary flow leading to increased microbial growth in the mouth
81
Give examples of organisms resistant to gastric acid?
Mycobacterium TB
| Enteroviruses e.g. Polio, hep A and coxsackie viruses
82
What innate cellular defences does the GIT have?
Neutrophils, eosinophils, basophils, mast cells (produce histamine, vasodilation and capillary permeability) and macrophages
83
What can cause liver failure?
```
Viral hepatitis
Alcohol
Drugs
Industrial solvents
Mushroom poisoning
```
84
What is hepatic encephalopathy?
Increased blood ammonia due to down regulation of the urea cycle and production by colonic bacteria causes confusion and cognitive impairment
85
What is cirrhosis?
Hepatic fibrosis and chronic inflammation leading to portal venous hypertension causing portosystemic shunting and toxin shunting.
86
Where might you find portosystemic shunting?
Oesophageal varicies
Haemorrhoids
Caput medusae
87
Where would you find modular GALT?
Tonsils
Peyer's patches
Appendix
88
What causes appendicitis?
Lymphoid hyperplasia at base
Purulent appendicitis (common in epidemics of chicken pox)
Faecolith blockage
89
What may cause gut ischaemia?
Arterial disease
Systemic hypotension
Intestinal venous thrombosis
90
What liver function tests are available?
Hepatocellular damage- AST/ALT
Cholestasis- bilirubin, alkaline phosphatase
Synthetic function- albumin, prothrombin time
91
What is pre hepatic jaundice?
Excessive haemolysis causing unconjugated hyperbilirubinaemia, anaemia, reticulocytosis, raised LDH and decreased haptoglobin
92
What causes excessive haemolysis?
RBC membrane defects, Hb abnormalities and metabolic defects
Immune, mechanical, infection
Gilbert's, Crigler-Najjar or Dublin-Johnson syndromes
93
What is hepatic jaundice?
Deranged hepatocyte function and cholestasis causing mixed hyperbilirubinaemia, raised AST/ALT/ALP and abnormal clotting
94
What affects hepatocyte function?
Hepatic inflammation, alcohol, haemochromatosis, Wilson's disease, drugs, cirrhosis, tumours
95
What is post-hepatic jaundice?
Obstruction of the biliary system (intrahepatic or extrahepatic) leading to conjugated hyperbilirubinaemia, no urobillinogen in urine and raised AST/ALT
96
What causes obstruction of the biliary system?
Hepatitis, drugs, cirrhosis, gallstones, carcinoma (head of pancreas), pancreatitis, sclerosing cholangitis
97
What is alcoholic liver disease?
Fatty change, with alcoholic hepatitis and associated fibrosis, liver cell necrosis and nodular regeneration.
Predisposes to hepatocellular carcinoma, liver failure, Wernicke-Korsakoff syndrome and encephalopathy
98
Symptoms of liver disease:
Jaundice, anaemia, bruising, palmar erythema, Dupuytren's contracture, decreased albumin causing ascites and oedema, decreas
99
What is hereditary haemochromatosis?
Autosomal recessive disorder of iron transport and deposition leading to cardiomyopathy, diabetes, hypogonadism, hepatitis etc.
100
What is Wilson's disease?
Autosomal recessive disorder of copper transport and storage leading to cirrhosis, dementia, kidney damage and Kaysar-Fleischer rings
101
What signs are associated with portal hypertension?
Splenomegaly, ascites, spider naavi, caput medusae, oesophageal/rectal varices
102
What is meant by fulminant hepatic failure?
Onset of hepatic encephalopathy within 2 months of diagnosis of liver disease, can be caused by hepatitis, drugs, pregnancy, alcohol etc.
103
What is encephalopathy?
Reversible neuropsychiatric deficit that causes flapping tremor, constructional apraxia, slow, slurred speech and personality changes
104
What factors can precipitate encephalopathy?
Sepsis, constipation, diuretics, GI bleeds, alcohol withdrawal
105
What is cholelithiasis?
Stones in the gall bladder, may be mixed, cholesterol or pigment stones
106
What is cholecystitis?
Stones lead to oedema, ulceration, fibroprurulent exudate causing pain, SIRS, pyrexia and sepsis
107
What are potential complications of gallstones?
Impaction causing biliary colic, empyema, obstructive jaundice, ascending cholangitis, acute pancreatitis, gallbladder carcinoma and perforation
108
What is charcot's triad?
Right upper quadrant pain
Jaundice
Fever
109
What is pancreatitis?
Inflammatory process caused by effects of enzymes released from pancreatic acinus
110
What causes acute pancreatitis?
Gallstones, alcohol, trauma, steroids, mumps, autoimmune, scorpion bite, Hyperlipidaemia, ERCP/iatrogenic, drugs
GET SMASHED
111
What causes chronic pancreatitis?
Chronic alcohol abuse. Cystic fibrosis and biliary disease
112
What are the components of intestinal epithelia?
Enterocytes- secrete enzymes into the brush border
Goblet cells
Paneth cells- produce antibacterial/antiviral toxins
Glandular cells
113
What is meant by anoikis?
Cell death that occurs as cells are detached from surroundings e.g. Shedding of epithelia in the intestines
114
What enzymes are secreted into the brush border to breakdown carbohydrates?
Amylase, isomaltose, maltase, alpha dextrinase, sucrase, lactase
115
How is glucose absorbed?
SLGT-1 symporter with sodium ions driven by concentration gradient established by sodium-potassium-ATPase, exits cell by GLUT2 channels (fascilitated diffusion).
Galactose also follows this pathway but fructose uses a GLUT-5 channel to enter the enterocytes.
116
What is the principle of oral rehydration therapy?
Glucose uptake stimulates sodium uptake via cotransporters so mixture of glucose and salt will stimulate maximum water uptake
117
What enzymes are used to digest proteins in the small intestine?
Pepsinogen from chief cells
Trypsinogen converted to trypsin
Endopeptidases hydrolyse inferior peptide bonds
Exopeptidases hydrolyse from C-terminal ends
118
How are amino acids and small peptides absorbed into the intestines?
Na+-amino acids cotransporters
| Dipeptides, tripeptides moved by H+-cotransporters and converted to amino acids using cytosolic peptidases
119
How is calcium absorbed?
Enters cells via fascilitated diffusion driven by a concentration gradient established by calcium-ATPase on the basolateral membrane. Requires vitamin D and is stimulated by PTH
120
How is iron absorbed and transported?
Absorbed across the apical membrane then binds to apoferritin to cross the basolateral membrane, carried in the blood by transferrin
121
How is B12 absorbed?
In the terminal ileum bound to intrinsic factor secreted by gastric parietal cells
122
What is the motility of the small intestine?
Intestinal gradient between meals
Intestinal pacemakers have increased frequency proximally driving slow caudal progression
Segmentation moves contents back and forth mixing
Peristalsis
123
What is the motility of the large intestine?
Segmentation (haustra live shuffling)
| Mass movement moves content rapidly from transverse colon to rectum
124
What are haustra?
Small pouches formed by sacculation of the large intestine
125
How does defaecation take place?
Increased intrabdominal pressure and relaxation of the anal sphincters
126
What are the derivatives of the SMA that supply the colon?
Middle colic, ileocolic, appendicular
127
What are the derivatives of the IMA that supply the colon?
Left colic
| IMA becomes superior rectal as it enters the pelvis
128
What is meant by inflammatory bowel disease?
Group of conditions characterised by ideographic inflammation of the GIT, usually Crohn's disease and ulcerative colitis
129
What are features of Crohn's disease?
Ileum involvement common
Affects anywhere in GIT including mouth
Transmural
Skip lesions
130
What are the features of ulcerative colitis?
Begins in rectum
Can extend to the entire colon
Continuous pattern
Limited to the mucosa
131
What are the differences in presentation between Crohn's and ulcerative colitis?
Crohn's has loose stools that are non-bloody, RLQ pain and perianal inflammation
UC has bloody stools with mucus and lower abdominal pain
132
What pathology distinguished Crohn's from ulcerative colitis?
Crohn's has fibrosis, granulomas, cobblestone appearance
| UC has crypt abscesses and friable mucosa
133
What extra intestinal problems are associated with IBD?
Musculoskeletal pain, skin problems e.g. Psoriasis, primary sclerosing cholangitis, eye problems
134
How might you investigate for inflammatory bowel disease?
Blood work (anaemia), CT/MRI scans, barium enema, colonoscopy, stool cultures
135
What is meant by inflammatory bowel disease?
Group of conditions characterised by ideographic inflammation of the GIT, usually Crohn's disease and ulcerative colitis
136
What are features of Crohn's disease?
Ileum involvement common
Affects anywhere in GIT including mouth
Transmural
Skip lesions
137
What are the features of ulcerative colitis?
Begins in rectum
Can extend to the entire colon
Continuous pattern
Limited to the mucosa
138
What are the differences in presentation between Crohn's and ulcerative colitis?
Crohn's has loose stools that are non-bloody, RLQ pain and perianal inflammation
UC has bloody stools with mucus and lower abdominal pain
139
What pathology distinguished Crohn's from ulcerative colitis?
Crohn's has fibrosis, granulomas, cobblestone appearance
| UC has crypt abscesses and friable mucosa
140
What extra intestinal problems are associated with IBD?
Musculoskeletal pain, skin problems e.g. Psoriasis, primary sclerosing cholangitis, eye problems
141
How might you investigate for inflammatory bowel disease?
Blood work (anaemia), CT/MRI scans, barium enema, colonoscopy, stool cultures
142
What treatments are available for inflammatory bowel disease?
Aminosalicylates e.g. Sulfasalazine for flares and remission
Corticosteroids e.g. Prednisolone for flares only
Immunomodulators e.g. Azathioprine for fistulas and remission
143
What are the functions of colonic bacteria?
Synthesise and excrete vitamins e.g. K and B12
Prevents colonisation by pathogens
Kill non-indigenous bacteria
Stimulate development of MALT
Stimulate production of natural antibodies
144
What bacteria are commonly found in the mouth?
Strep/staph
Candida
Lactobacillus
Enterococcus
145
What is noma/cancum oris?
Tissue destruction of the mouth
146
What is Ludwig's angina?
Migration of streptococcal bacteria from sore throat to lymph nodes resulting in cellulitis which endangers life by compressing the larynx
147
What is Quinsey?
Abscess in tonsil, causing deviated uvula and inspiration stridor
148
What bacteria are found in the colon?
Bacterioides fragillus
E. coli
Enterococcus faecalis etc
149
What is the role of lactobacillus acidophilus in the vagina?
Commensals that converts glycogen to lactic acid which prevents other bacteria and Candida albicans growing. Broad spectrum antibiotics kill lactobacillus leading to vaginal thrush
150
What commensals commonly cause urinary tract infections?
E. Coli, enterococcus
151
What causes wet gangrene?
Clostridium perfringens is anaerobic and digests glucose producing ethanol and CO2 and a cardio toxin that causes sudden cardiac arrest
152
What are features of oesophageal carcinoma?
Squamous cell carcinoma or adenocarcinoma (Barrett's oesophagus)
Can spread directly through oesophageal wall
Causes dysphagia, weight loss
Investigation by endoscopy, biopsy, barium swallow
153
What are the features of gastric cancer?
Association with gastritis, epigastric pain, vomiting and weight loss
May be fungating, ulcerated. May be intestinal with gland formation or diffuse with signet ring cells full of mucin
Can spread through the wall to peritoneum, liver, lymph nodes
154
What are gastro-intestinal stromal tumours?
Derived from pacemaker cells (intestinal cells of cajal), unpredictable behaviour e.g. Pleomorphism
155
What conditions may predispose to adenomas of the large intestines?
Familial adenomatous polyposis- autosomal dominant condition (chromosome 5)
Gardner's syndrome- similar to FAP with bone and soft tissue tumours
156
What is the adenoma-carcinoma sequence?
Similar anatomical and geographical distribution of adenomas and carcinomas with synchronous/metasynchronous lesions
157
What is Duke's staging of colorectal adenocarcinoma?
A- confined to bowel wall
B- spread through wall but lymph nodes are clear
C- lymph nodes involved
158
What genetic mutations are associated with colorectal adenocarcinoma?
FAP, ras mutations, deleted in colorectal cancer gene, p53 loss or inactivation
159
What is a carcinoid tumour?
Rare endocrine tumour found in the appendix
160
What are the features of pancreatic carcinoma?
Symptoms- weight loss, jaundice, trousseau's sign (thrombophlebitis)
Firm pale mass that may be necrotic, cystic or haemorrhagic
Acinar tumours with zymogen granules, ductal adenocarcinomas, carcinoma of ampulla of vater
161
What types of islet cell tumours are there?
Insulinoma
Glucagonoma (causes necrotic migratory erythema)
VIPoma
Gastrinoma
162
What tumours of the liver are there?
Benign hepatic adenoma, bile duct adenoma, hamartoma, haemangioma
Malignant hepatocellular carcinoma, cholangiocarcinoma, hepatoblastoma
163
What causes small bowel obstruction and how would it present?
Vomiting early, mild distension, colicky pain, complete constipation occurs very late
Caused by adhesions, hernias, tumours and inflammation
164
What causes large bowel obstruction and how would it present?
Presents with significant distension, dull pain, absolute constipation, vomiting is late and faeculant
Caused by colorectal adenocarcinoma, diverticulum structure, hernia and volvulus
165
What signs of a sigmoid volvulus might you see on an AXR?
From left iliac fossa to RUQ coffee bean sign
| Dilatation of proximal bowel
166
What is toxic megacolon?
Colonic dilatation, oedema and pseudo polyps
