Week 2 Flashcards
(191 cards)
1
Q
Fundus purpose
A
Storage- not for long
2
Q
The esophagus goes to what part of the stomach
A
The Fundus
3
Q
Where does receptive relaxation occur?
A
Fundus- food entering from esophagus
4
Q
Where’s the Antrum? And for what (2)?
A
Near the pyloric sphincter (bottom part of stomach)
For mixing/grinding
And release of gastrin
5
Q
Three types of cell in gastric pits/glands?
A
Gastric neck cells
(Gland)
Parietal cells
Chief cells
6
Q
Gastric pit/gland secretions and where they come from?
A
Mucus = surface mucus cells and neck
Pepsinogen = chief cells
Hpl and intrinsic factor = parietal cells
Gastric =
7
Q
Release of HCL happens how?
A
CO2 then reacts with water IN cytosol of parietal cells
= carbonic acids that quickly dissociated into carbonic acid and hydrogen/proton
Proton pump with potassium coming in
Bicarbonate comes in = blood basic, stomach acidic. So in response chloride moves across into stomach lumen = HCL
And note that a gradient has been created so… water comes in to stomach as well
8
Q
Proton pump inhibitors inhibit what proton pump?
A
One involved in the secretion of HCL in the GI tract
9
Q
Example of proton pump inhibitors?
A
Omeprazole eg for heart butn
Lansoprazole
10
Q
Why is blood after eating more basic?
A
Because proton pump releases protons into the stomach lumen, in response bicarbonate comes from stomach into blood and that’s basic
11
Q
How is the proton potassium pump controlled? (Gastrin or histamine or acetylcholine)
A
Pump is activated if phosphorylated by kinase enzyme located IN parietal cells.
So inhibit kinase enzyme = inhibit pump.
12
Q
Way that gastrin encourages HCL production?
A
Gastrin = released into blood
= receptor in parietal cells of gastric pits
= release calcium
= encourages protein kinase c
= pump active
13
Q
You could never put the whole process on a flash card (which I reckon you’ll need to know) but see the release of more histamine starts a chain reaction that does what to the proton potassium pump?
A
Increase in activation of protein kinase a, which phosphorylates proton pump = more protons = more HCL
14
Q
How does acetylcholine affect the proton potassium pump?
A
Acetylcholine will be released from enteric or the parasympathetic system, = increase calcium = increase protein kinase a
15
Q
What’s the effect of Gastrin and acetylcholine basically to release HCL?
A
Increase calcium = activate protein kinase c and increase release of HCL
16
Q
What works to inhibit protein kinases (considering histamine, Gastrin, and acetylcholine)
A
Prostaglandins
17
Q
What has gastrin levels got to do with histamine levels and release of HCL therefore?
A
Gastrin and ACh stimulates ecl cells and causes greater release of histamine and thus stimulates parietal cells
18
Q
Difference in cephalic and gastric stage?
A
Cephalic = vagus/enteric nerve at sight/smell
Gastric = reflexes
19
Q
Why is the cephalic stage important? (Gastric acid secretion at sight/smell of food)
A
Because before food enters stomach, must have certain amount of acid ready for sterilisation.
20
Q
Which phase is inhibition of vagal activity when you’re eating etc
A
Intestinal phase
21
Q
What leads to the intestinal phase (after the gastric phase)?
A
When you stop thinking about food = end cephalic stage = inhibit vagal activity.
Decrease in pH due to HCL, therefore inhibit release of gastrin (negative feedback)
22
Q
Half way between asis and pubic tubercle and inch above = what
A
Deep ring
23
Q
Which ring is the aponeurosis of the external oblique muscle?
A
The superficial ring
24
Q
Of gastric glands, the mucous neck cells, the chief cells and the parietal cells secrete what
A
Mucous
Pepsinogen
Intrinsic factor and HCL
25
Proton potassium pump is activated when phosphorylated by what enzyme located in parietal cells
Protein kinase enzyme
So inhibit this enzyme and you inhibit the pump
26
Gastrin, histamine and acetylcholine help control the proton potassium pump…which two do this by increasing calcium?
Gastrin and acetylcholine. Think gAstrin and Acetylcholine and cAlcium. Vs hIstamine.
27
What stops the cephalic stage of gastric acid secretion?
Stop eating = down vagal activity
28
What stops the gastric stage of gastric acid secretion?
Down pH = up HCL = down gastrin
29
What stops the intestinal stage of gastric acid secretion
Duodenum usually alkaline, so acid in stomach that’s gone past sphincter = enterogastric/ splanchnic reflex to inhibit
S cells in mucosa of duodenum release secretin which will go to blood and reach antrum/ G cells to inhibit directed
30
Inhibition of gastric acid in the intestinal phase is due to the introduction of what in the duodenum?
Acid and fat/carbs in the duodenum
Acid = enterogastric/ splanchnic reflex = secretin from s cells in the mucosa, = inhibit gastrin directly on g cells (travel through the blood)
Fat = GIP gastric inhibitory peptide = inhibit release of gastrin
31
Secretin is an example of what
An enterogastrone, just like GIP
32
When are enterogastrones released?
In response to acid mainly , but also fatty acids and monoglycerides in duodenum and hypertonic solutions I.e. solutions that have lots of molecules
33
Why are entergastrones released? Eg gastro inhibitory peptide from g cells and secretin from s cells
To prevent acid build up in the duodenum
34
Two methods of enterogastrones?
Inhibiting gastric acid secretion by:
Inhibiting gastrin
Inhibiting HCL release from parietal cells
35
What inhibits motility/contracts pyloric sphincter?
Enterogastrones
36
When does Pepsinogen (secreted by chief cells) become pepsin?
When stomach pH below 3 (often)
And if pH increases, becomes Pepsinogen again
We can’t store pepsin, it can degrade protiens
37
Why does pepsin deactivate when reaching the duodenum?
Because it’s inactivated at a neutral pH
38
What does mucus do? (2)
Protects the stomach wall from action of hydrochloric acid and hydrolytic enzymes (neutral pH)
And mechanical injury (slippy)
39
How come the stomach won’t digest itself?
Mucus
40
Where is the intrinsic factor/B12 complex absorbed?
Ileum
41
What is pernicious anaemia?
Defect in intrinsic factor
42
Why would defect in intrinsic factor cause less oxygen in tissues (that shows up
Because no vitamin B12 = no maturation of rbc
43
Thin or thick muscle, antrum Vs body?
Thick for antrum l
44
More digestion body or antrum
More in the antrum, more secretion of enzymes in body
45
Is there mixing of food in the body of stomach?
No
46
Mixing/ grinding of food into smaller molecules due to which muscles
Oblique
Not long and circular
47
Pyloric sphincter controls against hyper acidity in the intestines
True
48
Why only small amount of chyme (gastric content) in the duodenum?
Pancreatic juice/enzymes can’t work in acidic conditions
Hence control of neutralising bicarbonate release
49
Further mixing happens when pyloric sphincter is shut why?
Antral contents, forced back towards the body when closed during contraction
50
How many waves per minute
Like, 3
51
Where are the pacemaker cells located? That controls peristalsis
Longitudinal muscle layer
52
Depol of pacemaker cells in the longitudinal muscle layer, is that spontaneous?
Yes
53
What is the slow wave (peristaltic wave) rhythm of the stomach called?
Basic electrical rhythm
54
What does sub threshold mean? Of the slow waves caused by the pacemaker cells
Not enough to initiate action potential, so need further depol from somewhere else
55
Further depol for action potentials for small waves comes from what
Acetylcholine or gastrin
56
Distension of stomach causes two different types of reflexes:
Long = vagus
Short = enteric nervous system
57
Distension of stomach causes long reflex (vagus) and short reflex (enteric nervous system)… both of these will increase the release of what?
Acetylcholine = increase force of contraction by adding extra depol for the small waves
58
Where is bicarbonate released from?
(Activated by acid)
Submucosal glands called brunner’s gland (of the duodenum)
Also liver and pancreas (triggered by a cells/secretin due to acid)
59
Is there bicarbonate present in bile?
Yes
Hence why acid detection = s cells = secretin in blood to pancreas and liver = release bile
60
Bile duct takes to where
The duodenum
61
What is the pancreatic head surrounded by?
The C shaped duodenum
62
Tail of pancreas touches what
The spleen
63
Is the pancreas exocrine or endocrine?
Both
Via blood (endocrine)
And via ducts (exocrine)
64
What part of the pancreas is responsible for the secretion of hormones? (Endocrine)
Pancreatic islets called islets of Langerhans
65
Where does insulin come from
Islets of langerhans in the pancreas
66
Which two hormones control blood glucose level?
Insulin and glucagon
67
But what hormone controls the secretion of insulin and glucagon?
Somatostatin
68
Where does somatostatin come from?
The pancreatic islets called langerhans islets
69
What does insulin do Vs glucagon
Insulin = decreases blood glucose levels
Glucagon = increases blood glucose levels
70
What cells of the pancreas responsible for exocrine
Acinar cells
Which form lobules
71
Enzymes from pancreas come out from where
Acinar cells in the body which form lobules
72
Enzymes are secreted from Acinar cells which form lobules, in the body of the pancreas. Where else in intestines are enzymes secreted?
Duodenum
73
Is lumen of the gastrointestinal tract considered part of the body?
Yea
74
What are lobules (Acinar cells for exocrine) of the pancreas connected by?
Intercalated ducts
75
Lobules are connected by intercalated ducts. However, we have other ducts, big ones called what
Intralobular ducts
76
The main duct in the pancreas will lead to what
Main pancreatic duct will lead to the common bile duct
77
Go outwards from the lobules to the duodenum if you get what I mean
Lobules > intercalated ducts > intralobular ducts > main pancreatic duct > common bile duct > sphincter of oddi
78
What sphincter can control the release of bile and pancreatic juice from the bile duct?
The sphincter of oddi
79
What’s the purpose of the accessory pancreatic duct?
Plan B duct
80
Common bile duct vs pancreatic duct comes from where
Common bile is from the liver and gallbladder, but the pancreatic duct is from the pancreas
81
Alpha cells Vs beta cells Vs acini cells secret what
In lobules (exocrine) acini = enzymes
In the islets of langerhans, alpha beta gamma and delta.
Alpha = glucagon
Beta = insulin (no yo glucose therefore inferior like beta)
82
Exocrine function of the pancreas is important for what bodily function
Digestion- enzymes directly to the duodenum and also most food components are digested by pancreatic juice
83
Which cells of the pancreas produce the digestive enzymes?
Acini
84
Duct cells or Acinar cells in the pancreas exocrine release of bicarbonate?
Duct cells
Acinar for the ezymes
85
What is the sphincter of oddi responsible for secreting? (3)
Bike from gallbladder
Pancreatic juice
Bicarbonates
86
We know that Acinar cells release/contain digestive enzymes. These are stored as what
Inactive zymogen granules, and this is to prevent auto digestion of pancreas
87
Zymogens cause what to all components inside food
Hydrokysis
88
What enzyme converts trypsinogen to trypsin?
Enterokinase
89
If zymogens are the form of digestive enzymes that are inactive, what activated them?
Enterokinase converts trypsin into trypsinogen, then that converts every other zymogen to active forms
90
When does the pancreas secrete bicarbonate?
Acid from stomach = secretin to blood to pancreas = bicarbonate into small intestine and therefore neutralisation of intestinal acid
91
What is zymogen secretion stimulates by?
CCK
Cholecystokinin
92
Where is CCK (cholecystokinin) released from? (It’s secretion stimulates zymogen)?
From the duodenum
93
When is CCK released?
In response to presence of fatty acids, amino acids etc
So food= CCK = zymogens to digest said food
94
Would the long vagal reflex and short enteric reflex be triggered by what?
Arrival of digestive products in the duodenum
95
So you keep talking about the long and short reflex induced by distension of stomach. What happens.
Release of acetylcholine
96
Describe steps of how pancreatic enzymes are released
Stomach distension
CCK secreted
Go to pancreas
Release enzymes into small intestine
97
Retro sternal pain is pain that happens where
Discomfort behind the sternum in the chest
98
Retro sternal pain can either be:
Cardiac or GI tract in nature
99
Upper GI tract is what:
Esophagus and stomach
100
Could obesity cause weakening to the oesophageal sphincter?
Yes
Abdominal pressure = herniate mucosa into oesophagus
= hiatus hernia
101
Oesophagus = what
Squamous epithelium lining
Lots of layers = stretch
102
Why might hyperplasia occur in oesophageal reflux?
Thickening of squamous epithelium I’d always in contact with acid
103
When might ulceration occur of oesophageal epithelium?
When reflux is severe
= surface epithelium stripped off
104
Why might metaplasia occur in acid reflux?
Mucus helps to protect from acid
105
Severe acid reflux = fibrosis why?
Because mucosal metaplasia, not as resistant to sharp food boluses
106
What is ‘Barrett’s oesophagus’?
Change from squamous to glandular eouthelium
107
Metaplasia becomes dysplasia becomes neoplasia ie cancer. When is this reversible?
Metaplasia is reversible
108
Why is Barrett’s esophagus a precursor lesion to cancer?
Metaplasia could lead to dysplasia (mutations) and finally neoplasia
109
You can have squamous carcinoma or adenocarcinoma of the oesophagus. Which arises from Barrett’s oesophagus?
Adenocarcinoma (from metaplasia/mucosal glands that aren’t meant to be there but are, due to the acid)
110
obesity is a risk factor for which type of oesophageal cancer?
Adenocarcinoma, not squamous carcinoma
111
Is prognosis for oesophageal cancer okay?
No, poor prognosis, like 15%
112
What’s gastritis, and why do I think ‘ABC’?
Gastritis is stomach inflammation, and it’s:
Autoimmune
Bacterial
Chemical injury
113
Autoimmune gastritis would lead to what deficiency?
B12
114
What happens in bacterial gastritis?
H pylori bacteria produces potassium = bonds to pump = more acid
115
What food should be avoided in bacterial gastritis?
Potassium rich food like bananas
116
Why B12 deficiency in autoimmune gastritis?
Because your body is making antibodies to its own parietal cells incl to intrinsic factor
I.e. loss of specialised gastric epithelium
117
Autoimmune gastritis = up or down acid secretion
Down acid secretion
118
Bacterial gastritis = up or down acid production
Up acid production
119
Would bacterial gastritis be acute or chronic?
Both
120
What do you treat bacterial gastritis with?
Protein pump inhibitors
And
Antibiotics
Which you wouldn’t do to A version, that’s why biopsy is important
121
What usually causes chemical gastritis?
NSAIDS
So might give them with a proton pump inhibitor?
122
What are the other two things chemical gastritis could be caused by?
Alcohol
Or
Bile reflux
123
Would there be more mucous producing cells in chemical gastritis?
Ye
124
Imbalance between acid secretion and mucosal barrier is caused by what?
Peptic ulceration
125
Why might there be bleeding, perforation and healing by fibrosis (leading to obstruction) in a peptic ulceration?
Because stripping surface epithelium = exposing underlying nerves, blood vessels etc, leads to complications
126
How could a peptic ulceration lead to hematemesis? What do you do?
Vomiting blood
Blood vessel exposed due to ulceration
Ulcers ablated, or, elastic bands put on the blood vessels
127
Cancer in the oesophagus can be squamous or adenocarcinoma. What about in gastric cancers?
Just adenocarcinoma because it’s all glandular epithelium
128
What’s transcoelomic spread?
Spread within the peritoneal cavity
129
Where does the esophagus start and end
Cricoid cartilage at C6, and ends at T11-12
130
Walls of the intra-abdominal section of the oesophagus are compressed when there is what
Positive intea-abdominal pressure
131
During oesophageal peristalsis, the sphincter is what
Relaxed to allow food to enter the stomach
132
Mucosal rosette is formed by what
Acute angle between oesophagus and the stomach
133
How might food like alcohol or nicotine result in increased amount of reflux/heart burn?
It relaxes the o sphincter
134
What’s GORD?
Persistent reflux and heartburn can lead to ‘gastro-oesophageal reflux disease’
135
Odynophagia meaning?
Pain with swallowing
136
Odynophagia (pain with swallowing) has what associated features?
Weight loss
Regurgitation
Cough
137
What is the commonest cause of dysphasia?
Benign structure (narrowing)
Sometimes malignant as well
138
Would you ever investigate oesophageal disease with looking at pH?
Yes
PH-metry
139
What does manometer do?
Measure pressure waves in oesophagus with catheter
140
Hypermotility disorders look like what
Corkscrew appearance on Ba swallow
Let’s be honest,you’ll need to look this up.
141
Do people with gord always experience symptoms eg heart burn, water brash etc?
NO! Not always!!!
142
When would an endoscopy be performed in GORD?
When alarm symptoms such as
Dysphagia
Weight loss
Vomiting
143
Is presentation of oesophageal cancer late or early?
Late saldy
144
Where does h pylori of gastritis live?
Surface mucosa, not penetrating the epithelial layer
145
CLO test is what and involves what
Is a urease-dependant diagnostic test
Taking biopsy from stomach, putting it into test with urea to see if ammonia if formed, if so h pylori bacteria
146
Eradication of h. Pylori looks like what?
Triple therapy for 7 days:
Clarithromycin
Amoxicillin
Omeprazole
147
When endoscopy? (ALARM)
• Anorexia
• Loss of weight
• Anaemia - iron deficiency
• Recent onset >55 years or persistent despite treatment
• Melaena/haematemesis (GI bleeding) or mass
• Swallowing problems - dysphagia
148
When do we move dyspepsia patients to secondary care?
If symptoms persist and bacteria is gone
So start PPI trial for. Few weeks
149
What’s a jejunostomy?
Feeding tube into jejunum (rather than stomach eg if stomach has moved due to surgery- pulled up into chest and reattached)
150
Resp. fitness is affected after oesophageal resection?
True
They deflate the lungs
So go on cardiorespiratory fitness regimes couple of months
151
Can you do keyhole surgery for paraesophageal hiatus hernia?
Yes
The entire stomach could actually be in the chest, so could take longer, but yes
152
For patients struggling with chemotherapy regime before surgery, what about their fitness for surgery?
Maybe be worried tbh
153
Which side do we cut for esophagus? Remembering you’ve got the sternum and heart right there. Meaning what:
Posterior mediastinal, so we’d have to deflate the right lung
154
What is the largest gland AND the largest organ or the body?
The liver
155
Does the liver have only endocrine or only exocrine functions?
Both
Hormones into blood
And
Enzymes for digestion eg in bile
156
Examples of disaccharides
1) lactose = glucose + galactose (lactase)
2) sucrose = glucose + fructose (sucrase)
3) maltose = glucose + glucose (Maltase)
157
Pepsin catalysed the hydrolysis of peptide bonds in proteins. What environment does it require
Acidic
158
Does the duodenum ever secrete digestive enzymes
No
159
What does CCK stimulate the release of
Zymogens from pancreatic acini
160
In micelles of fats, where do the polar portions face
Outside
161
What does conjugation of bile acids with amino acids do
Increase solubility
162
Does peristalsis ever stop
No
163
Secretion from brunners glands is stimulated by what
Secretin
164
CCK stimulates what
Pancreatic enzyme secretion and bile secretion
165
Segmentation contractions in the small intestine are initiated by what?
The arrival of food in the stomach
166
Bicarbonate is secreted into bile by duct cells in the liver
Treu
167
What does trypsin do?
Starts the digestive process of protein molecules by cutting long chains of amino acids into smaller pieces
168
If trypsin Starts the digestive process of protein molecules by cutting long chains of amino acids into smaller pieces, what coverts trypsinogen to trypsin?
Enterokinase
169
What are Pepsinogen secreted by
Chief cells
170
T or f, secretin is released from a cells in response to acid in the duodenum
T
171
The arrival of chyme in the duodenum, triggers a reflex activity in the splanchnic nerve that does what
Inhibit gastric secretion and emptying
172
Bike pigments are derived from what
Haemoglobin
173
Does sympathetic activity decrease or increase the intensity of segmentation contractions?
Decrease
174
Can fructose be absorbed passively across the colonic epithelium?
Yes bc it’s a monosaccharide. The only hexose sugars that can be absorbed are fructose, glucose and galactose
But if disaccharides- nah mate
175
Secretions from brunners glands aid in neutralisation. Of gastric acid
True
Cuz it’s mucus
176
Where is fructose absorbed?
Across epithelium of small intestines
177
So we know that pancreas releases digestive enzymes… but we don’t want to digest the pancreas. So how are they stored?
As zymogens
178
Example of zymogen?
which is the inactive form of digestive enzyme, stored safely in the pancreas.
Trypsinogen
(which becomes trypsin and converts all other zymogens to active forms)
179
What does the brush border Enterokinase do
Concerts released pancreatic trypsinogen into trypsin
(Which converts all other zymogens into active forms)
180
What part of the gastric put secretes bicarbonate rich fluid to neutralise gastric acid?
Brunner’s glands
181
What produces vitamin k
Colonic bacteria
182
Stomach distension leads to the inhibition or stimulation of gastric secretion?
Stimulation obvs
183
When are Pepsinogens from chief cells secreted?
By parietal cells in response to lowering pH
184
Where in the small intestine is the intrinsic factor/vitamin B12 complex absorbed?
In the terminal ileum
185
What stimulates the secretion of bicarbonate from brunners glands
Secretin
186
Bile salts are reabsorbed and recycled to the liver via the hepatic portal vein. Where about is the bile salt reabsorbed in the small intestine?
Distal ileum
187
Lysozyme in saliva does what
Cleave a component of bacterial cell walls ie it’s bactericidal
188
Proteins are broken down into amino acids, how are these co-transported?
With Na
189
Intensity of segmentation contractions increase follow increase in what activity, para or not
Parasympathetic
190
What nervous stimulation leads to profuse watery saliva
Facial and glossopharyngeal nerves
191
CCK causes gall bladder contraction, leading to bile expulsion. Therefore guess what sphincter is also caused to relax?
Sphincter of oddi
To permit bile entry into the duodenal mucosa
