Key Facts Flashcards
1
Q
What is the role of Chief cells within the stomach?
A
Pepsinogen producers
2
Q
Describe how TAGs are absorbed from the gut
A
Emulsified by bile and lipase to Fatty Acids. These then enter the enterocytes and reformed into TAGs. The TAGs combine to form chylomicrons, which enters lacteals and travel down lymphatics to empty into the subclavian vein.
3
Q
Give 5 roles of the Liver
A
- Iron storage/ Glycogen storage
- Detoxification (Cyt P450)
- Making Albumin
- Bile production
- Gluconeogenesis
4
Q
How is B12 absorbed?
A
Parietal cells make intrinsic factor to bind B12. B12 is then absorbed in the ileum. If no intrinsic = pernicious anaemia.
5
Q
Where does most nutrient absorption occur?
A
Jejunum
6
Q
Where does most water absorption occur?
A
Ileum
7
Q
Where is Bile reabsorbed?
A
Ileum
8
Q
What is the Parasympathetic nervous supply to the gut?
A
Vagal
9
Q
What is the Sympathetic nervous supply to the gut?
A
Splanchnic nerves
10
Q
Name the two components of the enteric nervous system
A
Submucosal
Myenteric
11
Q
How would you describe the innervation of the Parietal Peritoneum?
A
Somatic
12
Q
What is the Mesentery?
A
A double layer of visceral peritoneum that connects the intraperitoneal organs to the posterior abdominal wall
13
Q
What is the hole called between the Greater and Lesser sacs?
A
Foramen of Winslow
14
Q
Describe the Greater Omentum’s placement within the gut
A
Between the greater curve of the stomach, to the proximal duodenum, to the transverse colon - has an immune role
15
Q
What is the Greater Omentum formed from?
A
The dorsal mesentery
16
Q
Describe the Lesser Omentum’s placement within the gut
A
Between the lesser curve of the stomach, to the proximal duodenum, to the liver
17
Q
Where is the Foramen of Winslow?
A
In the lesser omentum
18
Q
What travels along the Lesser Omentum?
A
The portal triad
19
Q
What is the Lesser Omentum formed from?
A
Ventral mesentery
20
Q
Name 3 intraperitoneal structures of the gut
A
Stomach, Liver, Spleen
21
Q
Name 3 retropritoneal structures of the gut
A
Duodenum, rectum, descending colon, kidneys, ureters
22
Q
Name a secondarily retroperitoneal structure
A
Duodenum - due to stomach rotation
23
Q
Name the two pouches in women
A
Front: Vesico-uterine pouch
Back: Recto-uterine (Pouch of Douglas)
24
Q
Name the pouch in men
A
Rectovesical pouch
25
What does the foregut reach from and to? What is it supplied by arterially? What nerve?
Oesophagus to Proximal Duodenum (1/3)
Supplied by coeliac trunk
Supplied by Greater Splanchnic
26
What does the midgut reach from and to?
From Proximal Duodenum to 2/3 Transverse Colon
Supplied by SMA
Supplied by Lesser Splanchnic
27
Where does the hindgut reach from and to?
From 2/3 Transverse Colon to Rectum and Bladder
Supplied by IMA
Supplied by Least Splanchnic
28
What embryological layer is the gut from?
Intermediate mesoderm
29
What 2 components is the mesoderm split into during development?
Splanchnic and somatic
30
What is the mesentery derived from?
The splanchnic mesoderm
31
What does the left sac become during stomach rotation in gut development?
Left sac becomes the greater sac (LG)
32
What does the liver divide the ventral mesentery of the foregut into?
The Falciform ligament and the Lesser Omentum
33
What are the nerve roots of the Splanchnic nerves?
Greater - T5-9
Lesser - T10-11
Least - T12
34
Name the surface sections of the abdomen (9)
Right upper abdomen, Epigastric, Left upper abdomen
Right flank, umbilical, left flank
Right iliac fossa, suprapubic, left iliac fossa
35
Name the abdominal wall layers
External oblique, Internal Oblique, Transversus abdominis, Transversalis Fascia
36
What is the most common hernia?
Indirect
37
What are the vessels that mark the middle of the inguinal canal?
Epigastric vessels
38
What are the points of attachment for the inguinal canal?
ASIS -> Pubic symphysis
39
Which is lateral? The deep or superficial inguinal rings?
Deep
40
What must obliterate after gubernaculum descent?
Processus vaginalis -> becomes Tunica Vaginalis
41
Name the boundaries of the inguinal canal
Roof: Internal oblique/ Transversus abdominis
Anterior: External oblique (aponeurosis)
Posterior: Transversalis fascia
Floor: Inguinal ligament + lacunar ligament
42
What makes up the floor of the inguinal canal?
Inguinal ligament + Lacunar ligament
43
What is the role of the conjoint tendon?
Attaches internal oblique and transversus abdominis to bone for strength
44
What is an indirect hernia?
Exits via Deep inguinal ring, travels down to Superficial inguinal ring
45
What is a direct hernia?
Exits via Hesselbach's triangle to Superficial inguinal ring
46
What is a femoral hernia?
Below the inguinal ligament, down the femoral canal, out of the saphenous opening
47
What is an Omphalacoele?
Failure of the midgut to return to the abdomen
Covered in peritoneum
Many complications
48
What is Gastroschisis?
Defect in the ventral wall of the abdomen
| Gut not covered in peritoneum and exposed to amniotic fluid, but not as bad
49
What can Gastroschisis lead to?
Gut development problems eg. Atresia
50
What is an Umbilical Hernia?
Hernia through the umbilicus - covered in skin and fascia
51
What is "incarcerated" when referring to a hernia?
Stuck, cannot be reduced
52
What is "strangulated" when referring to a hernia?
Ischaemic, blood supply cut off
53
How does the Primary Intestinal Loop form and what happens to it?
Forms from the midgut, with the SMA as its central line
Herniates out of the umbilicus
Undergoes 3 90 degree counterclockwise rotations
54
What is Volvulus?
Where Sigmoid colon twists around the mesentery
55
What is the Vitelline duct?
A yolk sac remnant
56
What does a patent vitelline duct lead to?
Meckel's diverticulum, vitelline cyst, vitelline fistula
57
What is the rule of 2s when referring to Meckel's diverticulum?
2 foot from ileocaecal valve, 2% of population, under 2s, present at birth
58
What is pyloric stenosis and how does it present?
Hypertrophy of the pyloric sphincter at the end of the gut
| Causes projectile vomiting in infants
59
What is the anal canal divided in two by?
The pectinate line
60
Describe the blood supply, nerve supply, cell type and pain type felt of the superior anal canal
IMA
S2, 3, 4
Simple Columnar
Stretch only
61
Describe the blood supply, nerve supply, cell type and pain type felt of the inferior anal canal
Pudendal artery
S2, 3, 4
Stratified Squamous
Pain
62
What is Xerostomia?
Salivary gland blockage
63
What innervates salivary gland production?
Parasympathetics - glossopharyngeal
64
Name the 3 phases of swallowing and describe the key features
- Oral - conscious, bolus formed, pushed to back of mouth into oropharynx
- Pharyngeal - soft palate closes off nasopharynx, peristalsis occurs from constrictor muscles, UOS opens, epiglottis closes via suprahyoids
- Oesophageal - UOS closes, peristalsis
65
What are the afferent and efferent limbs of the Gag reflex?
Gloss (9) -> Vagus (10)
66
What precautions does the stomach have t prevent GORD?
Diaphragm and LOS + acute angle of entry
67
What happens in Barrett's oesophagus?
GORD leads to stratified squamous converting to columnar - adenocarcinoma
68
What do ECL cells in the stomach secrete?
Histamine
69
What is gastrin released by and what does it do?
G cells, increases Parietal cell acid production and histamine release
70
What is CCK released by and what does it do?
I cells in the duodenum and causes gall bladder contraction and release of peptides/zymogens, lipases, amylases from acini of pancreas
Relaxes sphincter of Oddi
71
What is Secretin and what does it do?
Released by S cells in the duodenum, causes HCO3- release from duct cells of the pancreas
72
Where is the antrum of the stomach?
Bottom
73
Where is the cardia of the stomach?
Entrance
74
Where is the fundus of the stomach?
Head
75
What can parietal cells be stimulated by?
Gastrin, Histamine, AcH from sympathetic system
76
What releases somatostatin and what does it do?
D cells, inactivates G cells and ECL cells
77
Name a PPI
Omeprazole/Lanzoprazole
78
Name a H2 inhibitor
Ranitidine
79
Name the 3 phases of digestion
- Cephalic
- Gastric
- Intestinal
80
Name 3 stomach defences
- Mucous producing cells
- High turnover rate of epithelial cells
- Prostaglandin release maintains high blood flow to cells
81
What is gastritis?
Inflammation of the stomach lining
82
Name 2 acute causes of gastritis
Alcohol, NSAIDs
83
Name 2 chronic causes of gastritis
H Pylori (gram negative rod), chronic NSAIDs, pernicious anaemia (autoimmune)
84
Give 2 virulence factors of H Pylori
Urease produced - neutralises pH around it by converting urea to ammonia - toxic
Flagellum gives good motility
85
How is H Pylori tested for?
Urease breath test
86
Where does H pylori have to colonise to increase H+ production?
Antrum
87
What is the treatment for H Pylori?
Metronidazole + Amoxicillin
88
Give 2 complications of Stomach Ulcers
Perforation
| Haemorrhage
89
What is Zollinger-Ellison syndrome?
Gastrin-secreting tumour of the pancreas
90
What osmolarity is chyme entering the duodenum and exiting?
Hypertonic
| Leaves isotonic
91
How do pancreatic secretions reach the duodenum?
Ampulla of Vater
92
What cells of the liver produce bile?
Hepatocytes
93
What is the duct that bile travels down to the duodenum in?
Common Bile Duct
94
What unique features do the walls of the small intestine have? (2)
Plicae circulares
| Microvilli
95
Describe the digestion of Starch in the gut
Starch consists of amylose and amylopectin (branched)
a1-4 and a1-6 bonds (branched)
A1-4 broken down by Amylase -> maltose + alpha dextrins
A1-6 broken down by Isomaltase
96
Name the two components of starch
Amylose and amylopectin
97
How is glucose absorbed in the gut
SGLT 2 and 1
98
Why does oral rehydration fluid contain Dextrose?
SGLT 1 -> Glucose imported with Na, brings water in
99
What can caused reduced absorption of B12 in the ileum?
Crohn's disease - villi destroyed
100
Name 4 symptoms of IBS
Bloating, flatulence, diarrhoea, cramping
101
What is Coeliac disease?
Allergy to gliadin portion of gluten
Damages mucosa of intestines, villi, reduces absorption
Leads to diarrhoea, weight loss, flatulence (less absorption)
102
How is Coeliac diagnosed?
IgA test
| Endoscopy - colonoscopy
103
Define Cirrhosis
Irreversible fibrosis of the liver from inflammation, hepatocyte necrosis and nodules
104
What are the types of hepatitis and which has a vaccine?
B and C
| B has a vaccine
105
Name a cause of non-alcoholic liver disease
Obesity/Diabetes
106
Name 4 causes of Cirrhosis
```
Alcohol
Obesity
Diabetes
Hepatitis
Hereditary haemachromatosis
```
107
Name 2 autoimmune causes of Cirrhosis
Primary sclerosing cholangitis - ANCA antibodies
Primary biliary cirrhosis
Bile ducts destroyed in both
108
Name 3 locations of Varices and a fact about each
Oesophageal - distal
Umbilical - caput medusa, via ligamentum teres
Anorectal - rectal veins fucked
109
Describe what happens in Hepatorenal syndrome
AKI due to cirrhosis
Portal hypertension leads to splanchnic artery vasodilation
RAAS is activated in response, causing renal artery vasoconstriction reducing kidney bloodflow
110
What are the risk factors for Gall stones?
4 Fs
| Fair, Forty, Female, Fat
111
Name the 3 types of Gall stone pathology
- Biliary cholic
- Acute cholecystitis
- Ascending cholangitis
112
What is Biliary Cholic?
RUQ pain, contraction against stone
113
What is Acute Cholecystitis?
Stone in cystic duct - NOT COMMON BILE
| RUQ pain, Murphy's sign positive,
114
What is Murphy's sign?
Finger below liver, breathe in, diaphragm pushes liver and gall bladder down
115
What is a Cholecystectomy?
Gall bladder removal
116
What is Ascending Cholangitis?
Infection in biliary tree behind stone
| RUQ pain, Murphy's sign positive, jaundice
117
Describe Acute Pancreatitis and its signs
Acinar cell injury and necrosis, leads to:
Vomiting
Epigastric pain that radiates to back
Bruising
118
What is Jaundice?
Raised bilirubin
119
How does Bilirubin travel? What happens to it in the liver?
Travels: Unconjugated, bound to albumin
| In liver: Conjugated, water soluble
120
List the causes of Jaundice
- Pre-hepatic - eg. haemolytic anaemias (thalassaemia, sickle cell, spherocytosis, splenomegaly
- Intra-hepatic - eg. cirrhosis, hepatitis, paracetamol toxicity
- Post-hepatic - eg. acute cholecystitis, ascending cholangitis
121
What signs will be seen with a Pre-Hepatic Jaundice?
Raised Unconjugated Bilirubin
122
What signs will be seen with Intra-Hepatic Jaundice?
Raised ALT/AST
123
What does raised AST mean?
Liver damage from Cirrhosis
124
What does raised ALT mean?
Acute liver damage - more specific to liver
125
What signs will be seen with Post-Hepatic Jaundice?
Coca-cola urine, pale stools
| Raised ALP, with raised Gamma-GT
126
What are the roles of the Large Intestine?
Water absorption via ENaC channels
| Vitamin K production
127
Name all of the arteries of the gut
SMA -> Jejunal, Ileal, Ileocolic, right colic, middle colic
| IMA -> Left colic, sigmoid, superior rectal
128
Name a unique feature of the large intestine
Has haustra caused by the incomplete outer muscle layer called the teniae coli
129
Name the two types of IBD
- Crohn's
| - Ulcerative Colitis
130
Name the unique features of Crohn's (9)
- Skip lesions
- Transmural
- Affects whole gut
- Non-bloody stools
- Cobblestone appearance
- Granuloma formation
- Fistulae common
- Strictures common
- Peri-anal disease
131
Name the unique features of UC (7)
- Always begins in rectum and moves up gradually
- Mucosal inflammation only
- Bloody, mucousy stools
- Inflammatory exudate in crypts
- Loss of haustra - lead pipe
- No fistulas
- No peri-anal disease
132
What are the treatments for IBD?
Immunosuppressants/corticosteroids
133
Which IBD can be cured?
UC - no skip lesions
134
Name the two categories of diarrhoea
Osmotic
| Secretory
135
How does Osmotic diarrhoea occur?
Ingestion of an osmotically active material eg. Lactose when lactose intolerant
Removal of material = solved
136
How does Secretory diarrhoea occur?
Excessive excretion of ions due to toxins or too little absorption due to SA reduction eg. coeliac
137
List 2 causes of constipation
Psychology
| Reduced colonic movement eg. Parkinson's/Toxic megacolon
138
What is Diverticulosis?
Outpouching of mucosa through the muscularis layer (usually along the vasa recta)
139
What causes Diverticulosis?
Low fibre diet leading to increased luminal pressure
140
What is acute Diverticulutis?
Outpouchings of mucosa become inflamed or perforate, as the entrance to the diverticula is blocked by faeces and bacterial invasion/infection occurs
Perforation occurs - complicated if this occurs
141
What arteries make up the blood supply to the anal canal and what are their branches?
Superior rectal - IMA
Middle rectal - Internal iliac
Inferior rectal - Pudendal artery
142
What happens during porto-systemic anastamoses in anorectal varices?
Pressure rises, usually only superior rectal vein has to drain, but pressure too high
143
What does the pectinate line separate embyrologically?
Endoderm and ectoderm
144
What nerve supplies the external urethral sphincter of the anus?
Pudendal
145
What is the role of haemorrhoids within the anus?
Detect pressure in the rectum - contain a venous plexus that can inflate to help with continence
146
Describe the pathophysiology of internal haemorrhoids
No pain, lots of blood
| Treated with a high fibre diet, potentially band ligation
147
Describe the pathophysiology of external haemorrhoids
Very painful, surgery often done
148
What diseases would lead to malaena?
Peptic ulcers, cancers, oesophageal varices
149
Name 4 red flags of upper GI malignancy
Dysphagia, anorexia, anaemia, malaena
150
What are the most common types of upper GI malignancy?
SCC in oesophagus /Adeno in stomach
151
What type of malignancy is caused by Barrett's oesophagus?
Adenocarcinoma
152
What causes Bile duct cancer?
Primary sclerosing cholangitis
153
Where are Pancreatic cancers most commonly found?
The head
154
What are the 3 key features of lower GI malignancy?
1. Obstruction
2. Per rectum bleeding
3. Change in bowel habit
155
What is the difference between small intestine and large intestine bowel obstructions?
Small: vomiting first, constipation last
Large: constipation first, vomiting last
156
What causes other than cancer can lead to bowel obstruction? (2)
Diverticular disease/ Volvulus
157
Name 5 causes of Per rectum bleeding
UC, Haemorrhoids, Varices (ano-rectal), Gastroenteritis, Diverticular disease, Anal fissure
158
What is Tenesmus and what is it indicative of?
Urge to go when not needed
| Caused by tumour in anus
159
What type of cancer are all bowel cancers?
Adenocarcinomas
160
Name 3 risk factors for bowel cancer
- Family history
- IBD
- Poor diet
161
What type of tumours are found on the right side? (Ascending colon)
Fungating, less likely to cause obstruction
162
What type of tumours are found on the left side? (Descending colon)
Stenosing, tenesmus
163
Name 4 Gram Positive Gastroenteritis infections of the gut
Salmonella
E Coli
Shigella
Campylobacter
164
Name 4 Gram Positive Gastroenteritis infections of the gut in order of duration and if they have bloody diarrhoea
Salmonella - days, no bloody
E Coli - days, no bloody
Shigella - 1 week, bloody
Campylobacter - weeks, bloody
165
Name a Gram Negative infection of the gut, its pathogenicity factors and its treatment
Clostridium difficile
A toxin - enterotoxic, causes Cl- excretion
B toxin - cytotoxic
Treated with Vancomycin
166
What causes C difficile infections in hospitals?
Antibiotics destroy the gut microbiome, it can flourish
167
Name 2 complications of Clostridium difficile
Pseudomembranous colitis
| Toxic Megacolon
168
Name 2 causes of Viral gastroenteritis
Rota
Noro
Treated by oral rehydration, cause excessive Cl- secretion
169
Name 3 Parasitic gastroenteritis causes
- Cryptosporidium
- Giardia lamblia
- Entamoeba histiolytica
170
What are the complications of Entamoeba histiolytica? How is ti treated?
Metronidazole
| Can cause toxic megacolon/abscesses
171
Name a cause of Primary Peritonitis
Spontaneous Bacterial Peritonitis - usually in end stage liver disease, ascitic fluid infection
172
Name a cause of Secondary Peritonitis
Peptic ulcer perforation
173
What is the clinical presentation of peritonitis?
Patient lies very still, knees flexed, shallow breathing
174
Name 2 causes of Bowel obstruction in children
Intussusception
| Meconium ileus
175
Name 2 causes of Small Bowel obstruction in adults
Adhesions (post-operative)
| IBD - Crohn's
176
Name 2 causes of Large Bowel obstruction in adults
Colon cancer
Diverticular disease
Volvulus
177
How often is colicky pain felt in small bowel obstruction vs large bowel obstruction?
3-4 mins vs 10-15 mins
178
Why is the ileo-caecal valve important in large bowel obstruction
If competent, then the large bowel cannot decompress into the small intestine, which increases the risk of perforation and ischaemia
179
What is acute mesenteric ischaemia?
Reduction of blood supply to the gut due to occlusion of eg. SMA or reduced cardiac output
Causes pain, nausea, vomiting - disproportionately large symptoms
Must do surgery to resect ischaemic bowel
180
What is Toxic megacolon?
Inflammation and ischaemia of the large bowel
181
What are the ligaments from front to back of the abdomen?
Falciform -> Lesser Omentum -> Gastro-splenic -> Spleno-renal
