Week 4 Flashcards
1
Q
What are the 2 units in the medulla which control vomiting?
A
- Vomiting centre
2. Chemoreceptor Trigger Zone, CTZ
2
Q
What do the vital centres of the medulla oblongata regulate?
A
- Respiratory rhythm
- Heart rate
- BP
3
Q
What do the non-vital centres of the medulla oblongata regulate?
A
- Cough
- Sneeze
- Swallowing
- Vomiting
4
Q
Where is the Chemoreceptor Trigger Zone specifically located?
A
Area postrema in the floor of the 4th ventricle
5
Q
What stimuli activate the CTZ (chemorecptor trigger zone)?
A
- Chemical stimuli
- Site of action of drugs inhibit/ stimulate emesis
- Vestibular apparatus
6
Q
What are the 3 different types of vomiting?
A
- Projectile vomiting- gastric outlet / upper GI obstruction
- Haematemesis- fresh/altered blood ie. oesophageal varies, bleeding gastric ulcer
- Early-morning- pregnancy, alcohol, metabolic disorders (uraemia)
7
Q
What are the different triggers of nausea/vomiting?
A
- Stimulation of sensory nerve endings in stomach & duodenum
- Stimulation of vagal sensory endings in pharynx
- Drugs/endogenous emetic substances
- Disturbances of vestibular apparatus
- Various stimuli of sensory nerves of heart & viscera
- Rise in intracranial pressure
- Nauseating smells, repulsive sights, emotional factors
- Endocrine factors
- Migraine
8
Q
What is emesis?
A
Vomiting
9
Q
Describe Antihistamines?
A
- H1 histamine receptor antagonists
- Useful in numerous causes of n/v, including motion sickness & vestibular disorders
- Side-effects vary ie. drowsiness & antimuscarinic
10
Q
Give 3 examples of Antihistamines?
A
- Cinnarizine
- Cyclizine
- Promethazine
11
Q
Describe Antimuscarinics?
A
- Muscarinic receptor antagonists
- Blockade of muscarinic receptor-mediated impulses from labyrinth & visceral afferents
- Useful in motion sickness
- Side-effects constipation, transient bradycardia, dry mouth
12
Q
Give an example of a Antimuscarinic?
A
Hyoscine hydrobromide
13
Q
Describe Dopamine Antagonists?
A
- Act centrally as dopamine antagonists on CTZ
- Active against CTZ-triggered vomiting but not stomach-induced
14
Q
Give 3 examples of Dopamine Antagonists?
A
- Phenothiazines
- Domperidone
- Metoclopramide
15
Q
Describe 5HT3 Antagonists?
A
- Block 5HT3 receptors in GI tract & in the CNS
- Particularly useful in managing n/v in patients receiving cytotoxic & postoperative n/v
16
Q
Give 4 examples of 5HT3 Antagonists?
A
- Dolasetron
- Granisetron
- Ondansetron
- Palonosetron
17
Q
Describe Neurokinin 1 receptor antagonists?
A
Adjunct to dexamethasone & a 5HT3 antagonist in preventing n/v associated with chemotherapy
18
Q
Give 2 examples of Neurokinin 1 receptor antagonists?
A
- Aprepitant
2. Fosaprepitant
19
Q
Describe Synthetic Cannabinoids?
A
- n/v caused by chemo unresponsive to conventional anti-emetics
- Side-effects of drowsiness/dizziness
20
Q
Give an example of a synthetic cannabinoid?
A
Nabilone
21
Q
Describe Steroids?
A
- Alone to treat vomiting associated with cancer chemotherapy
- In conjunction with other antiemetics
22
Q
Give 2 examples of other Neuroleptics?
A
- Haloperidol
2. Levomepromazine
23
Q
Give 2 examples of Bulk Laxatives?
A
- Ispaghula husk
2. Methylcellulose
24
Q
Give 6 examples of Stimulant Laxatives?
A
- Bisacodyl
- Dantron
- Docusate sodium
- Glycerol
- Senna
- Sodium picosulfate
25
Give 2 examples of Softener Laxatives?
1. Arachis oil
| 2. Liquid paraffin
26
Give 4 examples of Osmotic Laxatives?
1. Lactulose
2. Macrogols
3. Magnesium salts
4. Rectal phosphates
27
Give 1 example of Peripheral opioid receptor antagonist?
Methylnaltrexone bromide
28
What are the 4 approaches for treatment of acute diarrhoea?
1. Maintenance of fluid & electrolyte balance
2. Antimotility drug
3. Antispasmodics
4. Occasionally antibacterial agent is indicated
29
Give 4 examples of Antimotility agents?
1. Codeine
2. Co-phenotrope
3. Loperamide (imodium)
4. Morphine
30
Give an example of a Adsorbents?
Kaolin
31
What are adsorbents NOT used for?
ACUTE diarrhoea
32
Give 3 examples of bulk forming drugs?
1. Ispaghula
2. Methylcellulose
3. Sterculia
33
What 5 things does Bile contain?
1. Bile salts
2. Bilirubin
3. Cholesterol
4. Lecithin
5. Plasma electrolytes
34
What is the treatment to dissolve gallstones?
Ursodeoxycholic acid
35
What is the treatment for biliary colic & acute cholecystitis?
- Opioid ie. Morphine/Pethidine parenterally
| - &/or diclofenac (NSAID) by suppository
36
Describe Colestyramine & its uses?
- Anion-exchange resin
- Forms insoluble complex with bile acids in intestine
- Relieves pruritus associated with partial biliary obstruction & primary biliary cirrhosis
37
What diseases can Colestyramine be used in?
- Hypercholesterolaemia
| - Crohn's disease
38
Name 2 benign (5%) tumours of the oesophagus?
1. Mesenchymal Tumours
| 2. Squamous papillomas
39
Name 2 Malignant tumours of the oesophagus?
1. Squamous cell carcinoma (90%)
| 2. Adenocarcinoma
40
Name 2 benign tumours of the stomach?
1. Polyps
| 2. Mesenchymal
41
Name 4 Malignant tumours of the stomach?
1. Carcinoma
2. Lymphoma
3. Carcinoid
4. Mesenchymal
42
What is the most common benign tumour of the oesophagus?
Leiomyomas (smooth muscle)
43
What are the 4 factors associated with Squamous cell carcinoma?
1. DIETARY- deficiency of vitamins (A,C,riboflavin), fungal contamination of foodstuff, high content of nitrates/nitrosamines
2. LIFESTYLE- hot drinks/food, alcohol & tobacco
3. OESOPHAGEAL DISORDERS- long-standing oesophagitis & Achalasia
4. GENETIC PREDISPOSITION
44
What is the incidence (in %) of Squamous cell carcinoma in the 3 different parts of the oesophagus?
- 50% in middle 1/3
- 30% in lower 1/3
- 20% in upper 1/3
45
What does squamous cell carcinoma look like?
Small gray-white, plaque-like thickenings that become tumourous masses
46
What are the 3 patterns of squamous cell carcinoma in the oesophagus?
1. Protruded polypoid exophytic (60%)
2. Flat, diffuse, infiltrative (15%)
3. Excavated, ulcerated (25%)
47
What are the histological changes in squamous cell carcinoma?
- Pleomorphism
- Hyperchromatism
- Mitotic figures
- Atypia
48
What are the clinical features of squamous cell carcinoma of the oesophagus?
- Dysphagia
- Extreme weight loss
- Haemorrhage & sepsis
- Cancerous tracheoesophageal fistula
- Metastases to lymph nodes (cervical, mediastinal, paratracheal etc)
49
What is the prognosis for a patient with squamous cell carcinoma in the oesophagus?
5% overall five-year survival
50
Describe Adenocarcinoma of the oesophagus?
- Lower 1/3
- Arise from Barrett mucosa (10%)
- Tobacco & obesity
51
What does adenocarcinoma of the oesophagus look like?
- Flat/raised patches or nodular masses
| - May be infiltrative/deeply ulcerated
52
Describe the histology of adenocarcinoma of the oesophagus?
Mucin-producing glandular tumours
53
What are the clinical features of adenocarcinoma of the oesophagus?
- Dysphagia
- Progressive weight loss
- Bleeding
- Chest pain
- Vomiting
- Heartburn
- Regurgitation
54
What is the prognosis of a patient with adenocarcinoma in the oesophagus?
20% overall five-year survival
55
What are benign polyps in the stomach?
Nodule/mass that projects above the level of the surrounding mucosa, usually in the antrum
56
Describe Non-neoplastic (90%) polyps of the stomach?
- Small & sessile (without stalk)
- Hyperplastic epithelium
- Cystically dilated glandular tissue
57
Describe neoplastic- adenomas (5-10%) of the stomach?
- Proliferative dysplastic epithelium
- Malignant
- Sessile / pedunculated (stalk)
58
What are the 3 factors associated with gastric carcinomas in the stomach?
1. ENVIRONMENTAL- H. pylori infection, diet, socioeconomic status, smoking
2. HOST- chronic gastritis, gastric adenomas, Barrett oesophagus
3. GENETIC FACTORS- blood group A, family history, hereditary nonpolyposis colon cancer syndrome, familial gastric carcinoma syndrome
59
How common are the different locations for gastric carcinomas?
- Pylorus & antrum (50-60%)
- Cardia (25%)
- Remainder in body & fundus
60
What are the 3 different macroscopic growth patterns of gastric carcinomas?
1. Exophytic
2. Flat/depressed --> Linitis plastica
3. Excavated
61
What is the morphology of Linitis plastica growth pattern?
- "Leather bottle"
- Diffuse infiltrative gastric carcinoma
- Mucosal erosion
- Markedly thickened gastric wall
62
What are the 3 different types of adenocarcinomas according to the Lauren Classification?
1. Intestinal type
2. Diffuse type
3. Mixed type
63
Describe the Intestinal type adenocarcinoma according to the Lauren Classification?
- Neoplastic intestinal glands resembling those of colonic adenocarcinoma
- Cell contain apical mucin vacuoles, abundant mucin may be present in gland lumens
64
Describe the Diffuse type adenocarcinoma according to the Lauren Classification?
- Gastric-type mucous cells, generally don't form glands, rather permeate the mucosa & wall as scattered individual cells/small clusters in "infiltrative" growth pattern
- Mucin expands malignant cells & pushes the nucleus to periphery, creating "signet ring"
65
Describe the spread of gastric carcinomas?
- Supraclavicular (Virchow) node
- Duodenum, pancreas, retroperitoneum
- Metastases to Liver/lungs
- Metastases to ovaries called Krukenberg tumour
66
What are the clinical features of gastric carcinomas?
- Asymptomatic until late
- Weight loss
- Abdominal pain
- Anorexia
- Vomiting
- Altered bowel habits
- Dysphagia
- Anaemic symptoms
- Haemorrhage
67
What is the prognosis of a patient with gastric carcinoma?
- Early: 90-95% five-year survival
| - Advanced: <15% five-year survival
68
What % of gastric malignancies does gastric lymphoma make up?
5%
69
What cell is involved in gastric lymphoma?
B cell lymphoma of mucousa associated lymphoid tissue (MALT)
70
What are gastric lymphomas associated with?
>80% associated with chronic gastritis & H. pylori infection
71
What is the prognosis of a patient with gastric lymphoma?
50% five-year survival
72
What is the morphology of gastric lymphoma?
- Commonly occurs in mucosa/superficial submucosa
- Lymphocytic infiltrate of the lamina propria surrounds gastric glands & massively infiltrated with atypical lymphocytes & undergoing destruction
73
What is the functional unit of the liver?
Liver lobule
74
What is the liver lobule composed of?
- Hepatocytes arranged in plates
- Bloodstream
- Bile canaliculi
75
What lies within the vascular spaces (sinusoids) of the liver?
Kupffer cells (phagocytic macrophages)
76
What are the 4 functions of the liver?
1. METABOLIC- carbohydrates, hormones, lipids, drugs & proteins
2. STORAGE- glycogen, vitamins, iron
3. PROTECTIVE- detoxification & elimination of toxic compounds, Kupffer cells ingest bacteria & foreign material from blood
4. BILE- formed in biliary canaliculi, emulsifies fats & route for waste removal
77
What are the 7 different classifications of liver disease?
1. Infection
2. Toxic/drug induced
3. Autoimmune
4. Biliary tract obstruction
5. Vascular
6. Metabolic
7. Neoplastic
78
What is Cholestasis?
Failure to produce or excrete bile
79
What is Intrahepatic cholestasis?
Problems in secretion of bile by hepatocytes due to damage
80
What is Extrahepatic?
Problems with flow of bile out of the liver due to obstruction
81
What happens do your urine and stool in Cholestasis & Jaundice?
- Darkened urine
| - Lighter stool
82
What leads to Jaundice?
- Accumulation of (conjugated) bilirubin in the blood
| - Excessive haemolysis
83
What is the definition of Acute Hepatic Failure?
Development of severe hepatic dysfunction within 21wks of onset of disease
84
What is the definition of Chronic Hepatic Failure?
Progressive decline in liver function with established disease
85
What are the 3 possible causes of Acute Hepatitis liver disease?
1. Poisoning (paracetamol)
2. Infection (Hepatitis A-C)
3. Inadequate perfusion
86
What are the 3 possible outcomes for patients with Acute Hepatitis liver disease?
1. Resolution (majority)
2. Progression to acute hepatic failure
3. Progression to chronic hepatic damage
87
What are the 3 common causes of Chronic Liver disease?
1. Alcoholic fatty liver
2. Chronic active hepatitis
3. Primary biliary cirrhosis
88
What are the 3 unusual causes of Chronic Liver disease?
1. alpha-1 AT deficiency
2. Wilson's disease
3. Haemochromatosis
89
What are the consequences of Chronic Liver disease?
- Cirrhosis
- Portal hypertension
- Ascites
- Renal failure
90
What is Cirrhosis?
Irreversible shrinkage of the liver & fibrosis
91
What are ascites?
Accumulation of fluid in the peritoneal cavity
92
What are the consequences of Liver Failure?
- Inadequate synthesis of albumin
- Inadequate synthesis of clotting factors
- Inability to eliminate bilirubin
- Inability to eliminate nitrogenous waste
93
What are signs of liver failure?
- Oedema
- Bruising
- Ascites
- Encephelopathy
94
What is the definition of Hepatic encephalopathy?
Poorly defined neuro-pschiatric disorder that occurs when products normally metabolised by the liver accumulate in the systemic circulation ie. ammonia
95
What are the current liver function tests?
- Aminotranferases: ALT & ASL for liver cell damage
- Bilirubin: for cholestasis
- ALP & γ-GT: for biliary epithelial damage & obstruction
- Albumin: for synthetic function
96
When would low albumin be found?
- Post-surgical/ITU due to redistribution
- Significant malnutrition
- Nephrotic syndrome
97
What is Bilirubin?
Pigment formed in liver by breakdown of haemoglobin & excreted in bile
98
Describe the differences between unconjugated & conjugated bilirubin?
- Unconjugated taken up by liver & conjugated
| - Conjugated excreted in bile
99
What is Urobilinogen?
Small amounts of bilirubin reabsorbed & excreted in urine
100
What is the net result of all the different types of cholestasis?
Accumulation of bilirubin in circulation = Jaundice
101
What are sensitive, non-specific enzymes of acute damage to hepatocytes that we can test?
AST & ALT
102
When is γ-GT (enzyme) raised?
Cholestasis, alcohol & drugs (phenytoin)
103
Where else can you find ALT enzyme?
- Cardiac muscle
| - Erythrocytes
104
Where else can you find ALP enzyme?
- Bone
- Gut
- Placenta
105
Where else can you find γ-GT enzyme?
- Bone
- Biliary tract
- Pancreas
- Kidney
106
Other than liver disease what other things can cause Bilirubin to increase?
- Haemolysis
| - Gilberts syndrome
107
Other than liver disease what other things can cause ALP enzyme to increase?
- Pregnancy
| - Adolescence
108
Other than liver disease what other things can cause AST enzyme to increase?
- Skeletal muscle disorders
| - MI
109
What are the advantages of current LFTs?
- Cheap
- Widely available
- Interpretable
- Direct subsequent investigation (imaging)
110
What are the disadvantages of current LFTs?
- In newly discovered diseases LFTs have no diagnostic value
- Little prognostic value in liver transplantation
- Little value for evaluating therapeutic success
- Do not assess liver "function"
111
What is the aetiology of liver disease?
- α-1 antitrypsin deficiency
- α-fetoprotein tumour marker
- Caeruloplasmin/copper studies
- Hepatitis serology
- Iron studies
- Autoantibodies
- Radiology
- Liver biopsy
112
Where is the spleen situated in relation to the ribs?
Left 9-11 ribs posteriorly
113
What are the 3 function of the spleen?
1. Mechanical filtration of red blood cells
2. Active immune response through humeral & cell mediated pathways
3. Haematopoesis until 5th month of gestation
114
What vessels does the Gastrosplenic ligament carry?
Left gastro-epiploic & short gastric branches of splenic artery (& veins)
115
What vessels does the Lienorenal (Splenorenal) ligament carry?
Splenic artery & vein
116
What can rib fractures of ribs 9-11 cause?
Rupture to the spleen, causing intraperitoneal haemorrhage
117
Why do you need to be careful when surgically performing splenectomy?
Avoid injuring the tail of pancreas when ligating splenic vessels
118
Describe the splenic artery?
- Largest branch of coeliac artery
- Along upper border of pancreas
- Divides into 6 branches which enter spleen at its hilum
119
Describe the splenic vein?
- Leaves hilum & runs behind tail & body of pancreas
| - Behind neck of pancreas, joins superior mesenteric vein to form portal vein (L1)
120
Describe the lymph drainage of the spleen?
- From hilum & pass through the few lymph nodes along course of splenic artery
- Drain into coeliac nodes
121
Describe the nerve supply of the spleen?
Coeliac plexus (foregut T5-9)
122
What does the portal vein drain?
- Lower 1/3 of the oesophagus to halfway down the anal canal
- Spleen, pancreas & gallbladder
123
What 2 things mix in the sinusoids of the liver?
Portal venous blood & oxygenated blood from hepatic artery
124
What union froms the portal vein?
Splenic & Superior Mesenteric veins
125
What does the left gastric vein drain?
Lower oesophagus & left end of the lesser curve of stomach
126
Where does the left gastric vein drain to?
Directly to portal vein
127
What does the inferior mesenteric vein join to form?
Joins splenic vein behind pancreas, then joining with portal vein
128
Where does the cystic vein usually drain into?
Portal vein, may drain into liver
129
Where does the right gastric vein drain into?
Right end of lesser curve of stomach directly to portal vein
130
What are the 4 sites of porto-systemic anastomosis?
1. Lower 1/3 of oesophagus (left gastric vein & oesophageal veins draining into azygos veins)
2. 1/2 down anal canal (superior rectal veins & middle & inferior rectal veins)
3. Para-umbilical veins (left branch of portal vein & superficial veins of anterior abdo wall)
4. Retroperitoneal ascending colon, descending, pancreas & liver portal tributaries anastamose with renal lumbar & phrenic veins
131
What do the para-umbilical veins drain into?
Falciform ligament & accompany the ligament theres
132
What are the 3 suprahepatic causes of portal blockage?
1. Cardiac disease
2. Hepatic vein thrombosis
3. IVC thrombosis
133
What is the normal portal venous pressure?
5-10mmHg
134
What is the hepatic cause of portal blockage?
Cirrhosis (alcohol, hepatitis)
135
What is the 2 infra-hepatic causes of portal blockage?
1. Portal vein thrombosis
| 2. Splenic vein thrombosis
136
What structures lie anterior to the Abdominal Aorta?
- Pancreas
- Splenic vein
- Left renal vein
- Duodenum
- Root of mesentery & coils of small bowel
- Lumbar veins
137
What structures lie on the right of the Abdominal Aorta?
- Cisterna chyli
- Thoracic duct
- Azygos vein
- IVC
138
What are the 3 unpaired, anterior/visceral branches of the Abdominal aorta?
1. Coeliac trunk (T12)
2. Superior mesenteric artery (L1)
2. Inferior mesenteric artery (L3)
139
What are the 3 paired visceral branches of the abdominal aorta?
1. Middle suprarenal arteries
2. Renal arteries (L1)
3. Testicular/ovarian arteries (L2)
140
What are the 3 posterior diaphragm/body wall branches of the abdominal aorta?
1. Inferior phrenic arteries
2. Lumbar arteries
3. Median sacral artery
141
What separates the IVC from the portal vein?
Entrance into lesser sac
142
What are the 4 Tributaries of the IVC?
1. 2 or 3 anterior visceral tributaries: hepatic veins
2. 3 lateral visceral tributaries: right suprarenal vein, both renal veins, right gonadal vein
3. 5 lateral abdominal wall tributaries: inferior phrenic vein & 4 lumbar veins
4. 3 veins of origin: 2 common iliac & median sacral vein
143
What are the primary imaging tools for the GI tract?
- X-ray
- CT
- Ultrasound scan
144
What are the secondary imaging tools for the GI tract?
- MRI
| - Fluoroscopy
145
What is the overall sensitivity of X-ray in GI tract imaging?
30%
146
What are the pros of X-ray in GI tract imaging?
- Widely available
- Easy
- Excludes bowel obstruction/perforation
147
What are the pros of Ultrasound in GI tract imaging?
- Easy, safe
- Clear visualization of solid organs, free fluid, aorta, pelvis
- Correlate imaging with tenderness
148
What are the pros of CT in GI tract imaging?
- Explosion
- Quick
- Accurate
- Allows better planning of surgery/intervention
149
What are the pros & cons of MRI in GI tract imaging?
- No radiation
- Good soft tissue delineation esp pelvis
- Long examination times
- Contraindications/claustrophobia
150
Describe the signs/symptoms of Acute Appendicitis?
- Periumbilical pain, nausea & vomiting
- Localised in right iliac fossa
- Challenging diagnosis
151
What imaging techniques would you use to diagnose Acute Appendicitis?
Ultrasound scan 1st then CT if this is inconclusive (no x-ray)
152
What increases incidence of Acute Diverticulitis?
Increase in age
153
What can be the complications of Acute Diverticulitis?
- Abscess
- Obstruction
- Perforation
- Fistulae
154
What are Colo-vesical fistula?
Communications between the lumen of the colon and that of the bladder
155
What imaging techniques would you use to diagnose Acute Diverticulitis?
- Plain x-ray (exclude obstruction/perforation)
| - CT
156
What is Acute Cholecystitis?
Inflammation of the gallbladder
157
What is Acute Cholecystitis almost always secondary to?
Gallstones
158
What 3 things is diagnosis of Acute Cholecystitis based on?
1. One local sign of inflammation (Right umbilical pain etc.)
2. One sign of inflammation (fever, WCC, CRP)
3. Confirmatory imaging
159
When would you use MRI for diagnosing Acute Cholecystitis?
If biliary tree is dilated
160
What can an Ultrasound scan of Acute Cholecystitis show?
- Gallstones
- Gallbladder wall thickening
- Local fluid
161
What does MRCP stand for?
MR cholangiopancreatography
162
What is Emphysematous cholecystitis?
Air in gallbladder
163
What are the common causes for small bowel obstruction?
- Adhesions
- Cancer
- Herniae
- Gallstone ileus
164
What are the symptoms/signs of small bowel obstruction?
- Vomiting, pain, distension
| - Increased bowel sounds, tenderness, palpable loops
165
Are adhesions seen in a CT scan of small bowel obstruction?
NO
166
What are the causes of large bowel obstruction?
- Colorectal cancer (60%)
- Volvulus (15%)
- Diverticulitis (10%)
167
What are the common causes of perforation?
- Perforated ulcer
| - Diverticular
168
What are the less common causes of perforation?
- Secondary to cancer
| - Secondary to ischaemia
169
What % of bowel blood flow defines bowel ischaemia?
<10%
170
What are the causes for bowel ischaemia?
- Arterial occlusion (60-70%)
- Venous occlusion (5-10%)
- Non-occlusive hypoperfusion (20-30%)
171
What is the role of plain film?
Obstruction & Perforation
172
What is the role of Ultrasound scan?
Right umbilical quadrant/ right iliac fossa pain
173
What is the role of CT scan?
Primary imaging technique for acute abdominal pain EXCEPT for acute cholecystitis/appendicitis
174
What does the liver synthesise?
- Albumin
- Clotting factors
- Complement
- α-1-antitrypsin
- Thrombopoietin
175
What does the liver produce?
Bile through conjugation of bilirubin
176
What does the liver breakdown?
- Drugs
- Insulin
- Ammonia
177
What does the Kupffer cells in the liver do?
Phagocytose old blood cells, bacteria & foreign materials from the bloodstream/gut
178
What is Jaundice?
- Yellowing of skin & mucosal surfaces, intense itch
| - Bilirubin >40μmol/L
179
What is Prehepatic Jaundice?
Haemolysis --> release of bilirubin from RBC's
180
What is Intrahepatic Jaundice?
Liver disease --> excess bilirubin in liver & bloodstream
181
What is Post-hepatic Jaundice?
Obstruction of bile outflow --> dark urine & pale stools
182
What zone in a hepatocyte will be effected worse with toxins?
Zone 3 next to the central vein
183
What 3 things can Alcoholic liver injury cause?
1. Steatosis
2. Cirrhosis
3. Acute hepatitis with Mallory's hyaline
184
What is Steatosis?
Fat deposition due to liver breaking down toxins instead of fats
185
What happens during the inflammatory reaction in Alcoholic liver injury?
Acetaldehyde binds to hepatocytes causing damage --> fibrosis
186
What is Mallory hyaline?
In damaged hepatocytes, you get aggregates of damaged hyaline protein which causes the cell to die
187
What 2 things leads to cirrhosis?
Fibrosis (collagen) + Regeneration --> Cirrhosis
188
What are the 3 morphological classifications of Cirrhosis?
1. Micronodular (<3mm)
2. Macronodular (>3mm)
3. Mixed
189
What are complications of cirrhosis?
- Liver failure
- Hepatic encephalopathy (ammonia)
- Hyperoestrogenism
- Low clotting factors (bleeding)
- Portal hypertension
- Azygous Vein shunting
- Hepatocellular carcinoma
190
What are signs of hyperoestrogenism?
- Palmar erythema
| - Gynaecomastia
191
What drug overdose can cause injury to liver cells (hepatocellular)?
Paracetamol overdose
192
What drug can cause injury to bile production/secretion cells (cholestatic)?
Methyl testosterone
193
Describe Acute Biliary Obstruction?
- Usually due to gallstones
- Colicky pain & jaundice
- Can cause cholangitis
194
How long does hepatitis have to last before it is classed as chronic?
>6 months
195
What are the 4 possible causes of Chronic Hepatitis?
1. Viral
2. Alcohol
3. Drugs
4. Autoimmune
196
What are the 3 steps for classification of Chronic Hepatitis?
1. Type- aetiology
2. Grade- degree of inflammation
3. Stage- degree of fibrosis
197
When does autoimmune hepatits usually present and in which gender is it more common?
- Mid to late teens
| - Females
198
What is Interface Hepatitis?
- Hepatocytes around portal triad become damaged
| - Because antibodies & cells are getting in there, triad becomes necrotic and swollen --> fibrosis
199
Describe Chronic Hepatitis?
- Plasma cells & swollen hepatocytes
- Fibrosis
- Patients may benefit from steriods
200
What are the stages of Primary Biliary Cirrhosis?
- Autoimmune destruction of bile duct epithelium
- Proliferation of small bile ducts
- Architectural disturbance
- Cirrhosis
201
What are the signs and symptoms of Primary Biliary Cirrhosis?
- Jaundice, pruritis, xanthelasmata
| - Raised ALP + IgM, AMA
202
What is Haemochromatosis?
Iron deposition in liver causing alteration of architecture --> fibrosis --> cirrhosis
203
What is the gene associated with Haemochromatosis?
HFE gene
204
What are secondary causes of Haemochromotosis?
Regular blood transfusions/iron supplements
205
What is the usual treatment of Haemochromotosis?
Regular venesection (give blood) to test iron & ferritin levels
206
Describe what α-1-antitrypsin Deficiency is and what can happen?
- Autosomal recessive disorder
- Proteins build up in hepatocytes as hyaline
- Lead to cirrhosis
- Associated with emphysema
207
What does NASH/NAFLD stand for?
Non-alcoholic steatohepatitis/Non-alcoholic fatty liver disease
208
What is NASH/NAFLD associated with?
Metabolic Syndrome (DM II, hypertension, decreased HDL cholesterol, increased triglycerides)
209
Describe Wilson's disease?
- Autosomal recessive disorder
| - Failure of liver to excrete copper in bile --> cirrhosis due to build up
210
Other than liver cirrhosis what other things can Wilson's disease cause?
- Neurological dysfunction by copper build up in brain
- Kayser-Fleischer rings
- Low caeruloplasmin
211
What is a Hamartoma?
Benign enlarged pocket of normal cells growing from an organ
212
Give examples of 2 benign liver tumours?
- Adenoma
| - Haemangioma
213
Give examples of 2 primary malignant liver tumours?
- Hepatocellular carcinoma
| - Cholangiocarcinoma
214
What is the aetiology of Hepatocellular Carcinoma?
- Aflatoxins (fungal origin)
- Hepatits B & C viruses
- Cirrhosis
215
What problems can arise in the Biliary system?
- Atresia
- Choledocal cysts
- Gallstones (cholelithiasis)
- Cholangiocarcinoma
- Obstruction
216
Where does Cholangiocarcinoma arise from?
Arises from bile duct epithelium anywhere in the biliary system
217
What disease is Cholangiocarcinoma associated with?
Ulcerative Colitis
218
What does Cholangiocarcinoma cause?
- Obstructive jaundice
- Itch
- Weight loss
- Lethargy
219
What can Cholangiocarcinoma lead to?
Rupture of common bile duct/gallbladder - prognosis poor!
220
What are the risk factors for Gallstones?
- Female, Fair, Fat, Forty, Fertile
| - Diabetes mellitus
221
What can gallstones cause?
- Cholecystitis
- Obstructive jaundice
- Cholangiocarcinoma
- Pancreatitis
- Cholangitis
222
Describe Acute Cholecystitis?
- Due to gallstones
- Initially sterile then becomes infected
- Lead to abscess/rupture
- RUQ pain (biliary colic), fever, nausea, vomiting
223
Describe Chronic Cholecystitis?
- Invariably related to gallstones
| - Chronic inflammation with wall thickening
224
What are sign for Annular Pancreas as birth?
- Polyhydramnios
- Low birth weight
- Poor feeding
225
What are the metabolic consequences of acute Pancreatitis?
- Decreased calcium
- Descreased albumin
- Increased glucose
226
How do you diagnose Acute Pancreatitis?
High serum amylase
227
What does chronic pancreatitis cause?
- Fibrosis of pancreas which may lead to diabetes mellitus
| - Reduced production of enzymes
228
What can cause Pancreatitis?
" I GET SMASHED"
- Idiopathic
- Gallstones
- Ethanol
- Trauma
- Scorpion poisoning
- Mumps
- Autoimmune
- Steroids
- Hypothermia
- ERCP
- Drugs
229
Describe Pancreatic Carcinoma?
- Adenocarcinoma
- Smoking & diabetes mellitus
- Painless, progressive jaundice
- Weight loss
230
What are the 5 types of IBD?
1. Ulcerative Colitis
2. Crohn's disease
3. Indeterminate colitis
4. Pseudomembranous colitis
5. Diverticulitis
231
Who is prone to getting Ulcerative Coltitis?
- Adolescence & early adulthood
- Female > Male
- Non-smokers
232
Describe Ulcerative Colitis?
- Relapsing/remitting course
- Inflammatory change in colon
- Rectum --> Variable length of colon
- Continuous, circumferential, superficial mucosal inflammation
233
What is PANcolitis?
When ulcerative colitis is over the entire colon
234
What can Ulcerative colitis cause?
- Iron-deficiency anaemia
- Raised inflammatory markers (CRP)
- Dehydration
- Damage cells leading to dysplasia --> colonic carcinoma
235
What does Ulcerative colitis look like macroscopically?
Multiple Pseudopolyps and ulcers along the mucosa of the colon
236
What does Ulcerative colitis look is microscopically?
- Inflamed mucosal layer
- Crypts shortened/Atrophic
- Crypt abscess
- Broad based ulcer eroding into superficial submucosa
- Plasma/neutrophils
237
Who is prone to getting Crohn's disease?
- Adolescence & early adulthood
- Female > Male
- Smokers
238
Describe Crohn's disease?
- Relapsing/remitting course
- Inflammatory change anywhere in GI tract
- Discreet, focal ulceration
- "Skip lesions"
- Terminal ileitis
239
What can Crohn's disease cause?
- Anaemia: absorption/blood loss
- Raised inflammatory markers (CRP)
- Dehydration
240
What does Crohn's disease look like macroscopically?
- Long streaks of linear ulceration
- Cobble stone appearance
- Fat wrap around entire circumference of the bowel
- Narrow lumen
- Fistulas (colon-bladder, colon-penis etc)
- Thickened/fibrotic mesentery
241
What does Crohn's disease look like microscopically?
- Crypts are shortened/Atrophic
- +/- Crypt abscesses
- Atrophic villi
- Granulomas, Neutrophils/Lymphocytes
242
Why does fat wrap around bowel in Crohn's disease?
Body is trying to contain the inflammation of the bowel wall by wrapping fat
243
What are some extra intestinal manifestations of IBD's?
- Inflammatory arthropathies
- Erythema nudism (Crohn's)
- Pyoderma gangrenosum
- Primary sclerosing cholangitis (UC)
- Iritis/Uveitis
- Aphthous stomatitis
244
What are the symptoms/signs of Ulcerative Colitis?
- Abdominal pain
- Bloody, mucoid diarrhoea
- Weight loss
- Lethargy
- Fever
- Tenesmus
245
What are the symptoms/signs of Crohn's disease?
- Abdominal pain after eating
- Watery diarrhoea
- Weight loss
- Lethargy
- Fever
- +/- Tenesmus
246
What infection can lead to Pseudomembranous Colitis?
C. difficile infection
247
What causes Diverticulitis?
Increased pressure, particularly within sigmoid colon, cause the mucosa to herniate out
248
What does Adenoma of the small intestine usually affect?
Enlarges Ampulla of Vater & turns it into a velvety surface
249
Describe the appearance of Adenocarcinoma of the small intestine?
- Napkin-ring encircling pattern
| - Polypoid exophytic masses
250
What are the signs/symptoms of Adenocarcinoma of the small intestine?
- Obstruction
- Cramping pain
- Nausea
- Vomiting
- Weight loss
251
What can Adenocarcinoma of the small intestine cause?
Obstructive Jaundice
252
Give 2 examples of benign non-neoplastic polyps of the colon & rectum?
1. Hyperplastic (90%)
| 2. Hamartomatous
253
Give 3 examples of benign neoplastic (adenoma) of the colon & rectum?
1. Tubular (most common)
2. Villous
3. Tubulovillous
254
Where are 1/2 of Hyperplastic polyps found?
Rectosigmoid colon
255
What is the histology of Hyperplastic polyps?
- Well-formed glands & crypts
- Lined by non-neoplastic epithelial cells
- Most of which show differentiation into mature goblet or absorptive cells
- No malignant potential
256
What are Juvenile Hamartomatous polyps?
Malformations of the mucosal epithelium & lamina propria in children <5
257
What is the histology of Juvenile Hamartomatous polyps?
- Abundant cystically dilated glands
- Inflammation is common
- Surfaces may be congested/ulcerated
- No malignant potential
258
What is Peutz-Jeghers polyps?
- Autosomal dominant syndrome due to mutation of STK11 gene located on chromosome 19
- Mucosal epithelium, lamina propria and muscular mucosa
259
What is the cause of neoplastic polyps- adenomas?
Arise as the result of epithelial proliferative dysplasia
260
What can Adenomas be a precursor for?
Invasive colorectal adenocarcinomas
261
What is the morphology of Tubular Adenomas?
- SMALL are smooth-contoured & sessile
| - LARGE are coarsely lobulated & have slender stalks, raspberry-like
262
What is the Histology of Tubular Adenomas?
- Stalk is composed of fibromuscular tissue & prominent blood vessels
- Presence of dysplastic epithelium which may show mucin vacuoles
- Degree of dysplasia is low-grade
- Carcinomatous invasion into submucosal stalk of polyp constitutes invasive adenocarcinoma
263
What does Villous Adenomas look like?
Velvety or cauliflower-like masses projecting 1 to 3cm above the surrounding normal mucosa
264
What happens when invasive carcinoma occurs (40%) in a Villous Adenoma?
No stalk as a buffer zone so invasion is directly into the wall of the colon
265
What are the clinical features of Colorectal Tubular & Tubulovillous adenomas?
Asymptomatic & many discovered during evaluation of anaemia or random bleeding
266
What are the clinical features of Villous Adenomas?
Symptomatic & often discovered because of obvious rectal bleeding
267
When is Endoscopic removal of a pedunculated adenoma is regarded as adequate?
1. The adenocarcinoma is superficial & does not approved the margin of excision across the base of the stalk
2. There is no vascular or lymphatic invasion
3. Carcinoma is not poorly differentiated
268
Can invasive adenocarcinoma arising in a sessile polyp be resected by polypectomy?
NO
269
98% of all cancers in the large intestine are __________?
Adenocarcinomas
270
What are the 5 dietary risk factors for Colorectal cancer?
1. Excess dietary caloric intake
2. Low vegetable fibre
3. High refined carbohydrates
4. Intake of red meat
5. Decreased intake of protective micronutrients
271
Describe the morphology of tumours in the proximal colon?
- Polypoid, exophytic masses
- Obstruction is uncommon
- Penetrate the bowel wall as subserosal & serial white, from masses
272
Describe the morphology of tumours in the distal colon?
- Annular, encircling lesions
- Margins are heaped up, firm & mid-region ulcerated
- Lumen narrowed, proximal bowel may be distended
- Penetrate the bowel wall as subserosal & serial white, firm masses
273
What is the histology for Colorectal cancer?
- Range from tall, columnar cells resembling adenomatous lesions to undifferentiated anaplastic masses
- May produce mucin
- Invasive tumour incites a strong desmoplastic stroma response
274
What are the clinical features of caecum & right colonic cancer?
- Fatigue
- Weakness
- Iron-deficiency anaemia
275
What are the clinical features of left-sided lesions?
- Occult bleeding
- Changes in bowel habit
- Crampy left lower quadrant discomfort
276
What is iron-deficiency anaemia in an older male seen as?
GI cancer until proven otherwise
277
All colorectal tumours spread to what 3 things?
1. Adjacent structures
2. Metastasis through lymphatics, blood vessels
3. Regional lymph nodes, liver, lungs, bones, serosal membrane of peritoneal cavity, brain & others
278
What is Dukes' Stage for Cancer?
A) Confined to submucosa or muscle layer (90+%)
B) Spread through muscle layer, no lymph nodes (70%)
C) Involving lymph nodes (35%)
279
What does the aggressive behaviour of carcinoid tumour correlates with?
- Site of origin
- Depth of local penetration
- Size of tumour
- Histological features of necrosis & mitosis
280
What is the morphology of carcinoid tumours?
- Usually solitary lesion
- Appendix most common
- Small intestine, rectum, stomach, colon
- Intramural or submucosal masses that create small polypoid or plateau-like elevations <3cm
- Solid, yellow-tan appearance on transection
281
What is the histology of carcinoid tumours?
- Neoplastic cells may form discrete islands, trabeculae, stands, glands or undifferentiated sheets
- Tumour cells have pink granular cytoplasm & round to oval stippled nucleus
- Tumour cells contain membrane-bound secretory granules
282
What are the clinical features of Carcinoid tumours?
- Rarely produce local symptoms
- Cutaneous flushes & apparent cyanosis
- Diarrhoea, cramps, nausea, vomiting
- Cough, wheezing, dyspnoea
283
What carcinoid tumours do NOT metastasise?
Appendiceal & Rectal Carcinoids
284
What is the overall % five-year survival rate for carcinoids?
90%
285
How does Gastrointestinal Lymphoma present?
Exhibit no evidence of liver, spleen, mediastinal lymph node or bone marrow involvement at the time of diagnosis
286
What does MALT stand for?
Mucosa-associated lymphoid tissue
287
What does IPSID stand for?
Immunoproliferative small-intestinal disease
288
Give an example of a B-cell lymphoma?
Burkitt lymphoma
289
Describe T-cell lymphomas?
- Associated with long-standing malabsorption syndrome
| - Prognosis poor
290
Give 3 examples of Mesenchymal Tumours?
1. Lipomas
2. Leiomyomas
3. Leiomyosarcomas
291
Describe Lipomas?
Well-demarcated, firm nodules <4cm arising within the submucosa or muscular propria
292
Describe Leiomyosarcomas?
Large, bulky, intramural masses that eventually fungate & ulcerate into lumen or project subserosally into abdominal space
293
Describe the 3 zones of the anal canal?
1. Upper (covered with rectal mucosa)
2. Middle (partially covered with transitional mucosa)
3. Lower (covered by stratified squamous mucosa
294
What are the commonest benign neoplasm of the anus?
Warts (condyloma acuminata)
295
What are 4 malignant carcinomas of the anal canal?
1. Basaloid pattern
2. Squamous cell carcinoma
3. Adenocarcinoma
4. Malignant melanoma (very rare)
296
What is Basaloid pattern carcinoma of the anal canal?
Immature proliferative cells derived from the basal layer of stratified squamous epithelium
297
What is squamous cell carcinoma of the anal canal closely associated with?
Chronic HPV infection
