Gastro Flashcards
Give the mucosa of the lip (histology)
- stratified squamous keratinising epithelium (at the skin margin)
- stratified squamous non-keratinising epithelium (in the mouth)
What is the muscle that surrounds the mouth called
- orbicularis oris muscle
- it is striated muscle
Give the mucosa on the ventral and dorsal surface of the tongue
- ventral surface has non keratinised stratified squamous epithelium
- dorsal surface has keratinised stratified squamous epithelium
Where do the extrinsic and intrinsic muscle fibres of the tongue attach to
- the extrinsic muscles attach to the lower jaw
- the intrinsic muscles attach to fibrous connective tiss under the mucosa
What are the papillae of the tongue
-the dorsum of the tongue has folds called papillae
Which papillae are most common and where are these usually located
-filliform papillae - tall, pointed and they cover the whole anterior 2/3 of the tongue
Which papillae are not so common and where are these usually located
-fungiform papillae - mushroom shaped and found at the tips and sides of the tongue
Where are taste buds usually found on the tongue
- on the lateral side of the fungiform papillae
- on the circumvallate papillae which separate the anterior 2/3 and posterior 1/3 of the tongue
Which papillae have taste buds and where are they located
- the circumvallate papillae
- v shaped row that separates the anterior 2/3 and posterior 1/3 of the tongue
What does the gland secretions of the parotid gland contain
-serous, enzyme rich secretions with alpha amylase that digest starch
What are the secretory cells of the parotid gland
-pyramidal with spherical nucleus
What type of epithelium lines the ducts that the acini drain into
-simple cuboidal epithelium that might become stratified at the end
What can striated ducts of the acini do to saliva
-adjust the ionic composition of saliva
What do the secretions of the sublingual gland contain
- sticky mucus that lubricates the mouth and bolus of food
- mucus made of high molecular weight mucopolysaccharide that is good at absorbing large amounts of water
What shape are the secretory cells of the sublingual glands
-appear swollen with oval nucleus squashed to the base of the cell
What do the secretions of the submandibular gland contain
-mix of serous and mucous secretions
What are the shapes of the secretory cells of the submandibular glands
-crescent shaped demi-lunes (half moons) which are the serous cells that lie at the end pf mucous secreting tubules
Which two salivary glands are major sources of epidermal growth factor that promote growth of the epithelium in the GI tract
- parotid gland
- submandibular gland
Give the epithelium of the surfaces of the epiglottis
- most of its surface is covered by stratified squamous epithelium
- the lower part of it’s posterior surface is covered by respiratory epithelium (pseudostratified columnar ciliated epithelium)
What are the four layers of the gastrointestinal tract
- innermost mucosa
- underlying submucosa
- external muscle coat (muscularis propria sometimes called muscularis externa)
- serosa (simple squamous epithelium covering the surface of the gut tube facing the peritoneal cavity)
Give the 3 layer components of the innermost mucosa in the GI tract
- lining epithelium (usually thrown into folds)
- lamina propria
- muscularis mucosa (ring of smooth muscle)
What does the submucosa in the GI tract contain
- glands and lymphoid tissue
- blood vessels that supply the gut
- Meissner’s plexus (part of the enteric nervous system)
What does the muscularis propria of the GI tract contain
- two layers of smooth muscle (circular and longitudinal), their contractions help to break up the food and propel it along the alimentary tract
- auerbach’s plexus (part of the enteric nervous system) in between the two layers of muscle
What epithelium lines the oesophagus
-stratified squamous non-keratinising epithelium
At what end does the oesophagus have a thicker and more prominent muscle layer in its muscularis mucosa
-the gastric (distal) end
Which end of the oesophagus contains skeletal muscle in its muscularis externa and which end contains smooth muscle
-the mouth (proximal) end of the oesophagus contains mainly smooth muscle
Which end of the oesophagus contains smooth muscle in its muscularis externa
-the gastric (distal) end contains mainly smooth muscle
What features might be present and different in the distal gastric end of the oesophagus especially below the thoracic diaphragm
- change of epithelium to gastric simple columnar epithelium
- large thin walled veins that can become oesophageal varicosities
- smooth muscle in the muscular externa
Give the 4 regions the stomach is divided into
- the cardia
- the fundus
- the body
- the pyloric
Which regions of the stomach are similar histologically in respect to their gastric glands
- the fundus
- the body
What are the longitudinal folds of the stomach mucosa called
Rugae
Give the epithelium of the stomach
-simple columnar epithelium punctuated by gastric pits where gastric glands drain into
Give the layers of the muscularis propria of the stomach
- oblique (innermost)
- circular (inner)
- longitudinal (outer)
Give the 3 main types of cell within the glands of the fundus and body of the stomach and what they do
- mucous neck cells - produce lubricatory acid-resistant mucus
- parietal cells - secrete HCI and intrinsic factor
- chief cells - produce pepsinogen
What is the difference between the gastric glands of the fundus (and body) of the stomach and the cardia and pylorus of the stomach
Cardia and pylorus
- the cardia and the pylorus of the stomach have gastric glands without parietal or chief cells
- the gastric glands of the cardia and pylorus are shorter and coiled
- the pyloric region also has G cells that produce gastrin and bombesin-like peptide
Fundus and body
- the fundus and body of the stomach contain full gastric glands (all the cells)
- the gastric glands of the fundus and body are longer and straight
In which layer of mucosa of the stomach are the gastric glands found
- in the lamina propria
- at the bottom of the gastric pits
What is suggested purpose of the elastic tissue present in the muscularis mucosa of the stomach
- causes collapse of stomach after emptying
- well developed in carnivores to prevent the perforation of the stomach wall by sharp fragments of bone
Which enzyme are numerous in parietal cells
-carbonic anhydrase
What does intrinsic factor do
-it is essential for the absorption of vitamin B12
Where are parietal cells (also called oxyntic cells) usually found in gastric glands
- under the mucous cells
- but towards the top of the gland
- on top of chief cells
What is the normal pH of gastric juice
-pH 2
Where are chief cells (also called zymogenic cells) found
- at the bottom of the gastric glands
- close to the muscularis mucosa
What do zymogenic cells do
- also known as chief cells
- secrete pepsinogen and lipases
For which tissue constituent (food) does pepsin have an affinity and what particular benefit does this confer in the process of digestion
- it digests proteins
- has an affinity for collagen
- facilitates breakdown of meat by attacking the connective tissue between muscle fibres
Where can G cells be found and what do they do
- in the pyloric region of the stomach
- they secrete gastrin
Give 3 additional types of cells found in all regions of the stomach
- enterochromaffin cells - produce serotonin
- delta cells (D cells) - produce somatostatin
- endocrin cells - vasocactive intestinal peptide (VIP)
Which mucosa layer would a lymph node be likely to be found in the stomach
-the lamina propria
What are the folds of the small intestine called
-plicae circulares
Where are plicae circulares most numerous and least numerous
- most numerous in the jejenum
- least numerous in the distal part of the colon
What epithelium cover the villi
- simple columnar epithelium with two main cell types
- enterocytes (absorptive cells) and goblet cells (mucus secreting cells)
Where are the cells that replace the enterocytes of the villi found
- the crypts of Lieberkuhn next to the villi
- process takes about 5 days
What is each villi made of
- small arteriole
- a thin walled venule
- blind ended lymphatic (lacteal)
- smooth muscle that rhythmically shorten
What are the crypts of Lieberkuhn
- contain a stem cell population
- basically the crypts next to each villi
- they are straight tubular glands going downwards
How many microvilli does each enterocyte have on its apical surface
- 300
- they form the brush border
What does the glycocalyx on the surface of the microvilli on the enterocytes do
- act as filter
- anchorage for exo-enzymes
How long is the duodenum
12 inches (30cm long)
What features help to distinguish the duodenum form other parts of the small intestine and what do they do
- brunner’s glands in the submucosa - secrete alkaline mucous that help to neutralise chyme from the stomach
- paneth cells - at the bottom of the crypts and secrete lysozymes which break down bacterial cell walls - they important in regulating bacterial flora of the gut (they have bright pink staining cytoplasm)
-few goblet cells and few plicae circulares
What features help to distinguish the jejunum from other parts of the small intestine and what do they do
- no brunner’s glands
- no peyer’s patches
- many goblet cells, long villi and short crypts
What features help to distinguish the ileum from other parts of the small intestine and what do they do
- large peyer’s patches in the submucosa erupting into lamina propria
- villi not as tall as jejunum
Which of the two layers of smooth muscle that make up the muscularis externa is thicker
-the inner circular layer is 4 to 5 times thicker than the outer longitudinal layer
What epithelium lines the vermiform appendix
-simple columnar epithelium with goblet cells
Which is not present in the vermiform appendix, the muscularis mucosa or the muscularis externa
-the muscularis mucosa is not present
Where do the taenea coli originate from
-the base of the appendix and then run the whole length of the large intestine
How does lymphoid tissue change in the appendix from childhood to adulthood
- large amounts of lymphoid tissue present in childhood but it decreases with age
- lymphoid tissue fills the lamina propria and submucos of the appendix
There is no intestinal villi in the colon and the lamina propria is restricted in volume due to the packed nature of the crypts, which feature is quite prominent in the colon
- the muscularis mucosa is quite prominent
- the mucosa and submucosa have lots of lymph nodules which are part of the gut-associated lymphoid tissue (GALT) that protects the body from invasion in the gut
What epithelium lines the rectum
-simple columnar epithelium
What epithelium lines the anal canal
-stratified squamous epithelium that becomes keratinised at the distal end
What does the submucosa of the anal canal contain
-plexus of veins that can form anal varicosities
What does the peri anal area of the anus contain
- hair follicles
- modified sebaceous glands
Taste buds detect acid, bitter, sweet and salty sensations. How are these distributed across the tongue?-
- Sweet tastes are detected by buds located mainly at the tip of the tongue
- salty tastes on either side towards the front of the tongue
- sour tastes further back
- bitter tastes are detected across the whole of the back of the tongue.
Parotid saliva contains immunoglobulins. Where are they produced and what is their function?
Plasma cells resident in the gland produce immunoglobulin A (IgAs). These IgAs are discharged into the saliva where they combine with proteinaceous “secretory pieces” also produced by the glands. These complexes are protected from digestion which allows the IgAs to reach the intestine unmodified.
A part of the duct of the parotid gland in known as a striated duct. What gives rises to these striations and with what function can they be associated?
- the striations are the result of deep invaginations of the basal plasmalemma of the cells and large elongated mitochondria that lie perpendicularly between them.
- a similar arrangement of organelles is seen in some of the cells of kidney tubules.
- this pattern is indicative of resorption of water and the transfer of ions across the cells.
- the striated tubules of salivary glands are capable of the secretion and resorption of water and ions from the saliva.
What is dental plaque?
It is a calcified deposit rich in dead or dying oral bacteria and food debris.
Do the enzymes produced by the salivary glands and swallowed continue to function in the stomach? Briefly explain your answer.
-The salivary enzymes have neutral pH optima and work rapidly in the mouth but they become inactivated by the acid environment of the stomach. However the enzymes continue to act in the stomach within the bolus of food where they are shielded from the gastric juices, until such time as the bolus is dispersed
The glands of the pyloric region of the stomach secrete gastrin. What is its function and what other cells of the stomach does it influence?
- Gastrin produced by endocrine secreting cells in the pyloric region of the stomach and in the duodenum
- promotes the secretion of HCl by the parietal cells of the body and fundus of the stomach.
Briefly, how and by what route are triglycerides mainly absorbed from the gut?
- although some triglycerides are absorbed into the capillaries of the intestine most are broken down into monoglycerides and fatty acids before being absorbed by the enterocytes.
- once taken up they are reconstituted and combined with proteins before being secreted through their baso-lateral membranes as macromolecular chylomicrons.
- these are then are taken up by lacteals and transported to the blood stream via lymphatics, ultimately finding their way to the liver by a somewhat circuitous route.
The gut has an intrinsic innervation consisting of a network of interconnecting nerves and ganglion cells. There are two main parts to this network. Where are they located in the wall of the gut and what names are given to these two main parts?
- there are two main subdivisions to the enteric nervous system.
- a plexus of nerves within the submucosa of the gut known as Meissner’s plexus regulates the mucosa and the processes of absorption and secretion
- a second interconnected plexus between the layers of muscle that make up the muscularis externa, known as Auerbach’s plexus regulates much of the contractile activity of the gut.
Soon after birth a baby acquires immunity through the acquisition of immunoglobulins provided by the mother’s milk. What structural features of the gut allow the uptake of these macromolecules and to what extent are the immunoglobulins digested by the enzymes of the gut?
- the enterocytes of the gut have specific receptor complexes that allow the uptake (undigested) of certain immunoglobulins that subsequently form part of the system of passive immunity.
- this system is at its most active in the neonate in response to immunoglobulins in the mother’s first milk (colostrum) but declines in significance within a few months.
What does the oral cavity do
- receives food
- chews food
- starts digestion
What does carcinoma mean
-a cancer arising in the epithelial tissue of the skin or the lining of the internal organs
What do salivary glands do
- produce saliva
- produce ezymes
What is sjorgen’s syndrome
- autoimmune disease of the salivary glands
- salivary glands are attached and destroyed by lymphocytes
- no saliva
What is hirschsprung’s disease
- lack of auerbach’s plexus which usually cause movement of food along bowel
- no movement of food
What are the interstitial cells of cajal and what is their significance
- in the muscular wall of the bowel
- pacemaker cells that give the pace of contraction of the muscles of the bowel
-prone to tumours (gastrointestinal stromal tumour or GIST) from a mutation in the C-kit gene
Give the order of cells from paneth cells ascending to the villi
- transit cells
- potential stem cells
- stem cells
- paneth cells
What are giardia lamblia
-parasites that sit on top of the intestinal mucosa and cause malabsorption because it takes nutrients from the host
What is ulcerative colitis
- inflammation of the colon
- that only affects the mucosa of the colon
Where is vitamin B12 absorbed
-in the terminal ileum
Where does the auerbach plexus lie
-in the muscularis propria between the inner circular and outer longitudinal muscle
What unique feature about the histology of the oesophagus helps to confirm its identity
- mucosal glands with squamous lined ducts in the submucosa
- lymphoid tissue in the submucosa
Give the histology of the posterior 1/3 of the tongue
-stratified squamous epithelium overlying waldeyer’s ring which has lymphoid tissue
What is faecal immunochemical testing
- FIT stands for Faecal Immunochemical Test.
- it is a type of faecal occult blood test which uses antibodies that specifically recognise human haemoglobin (Hb).
- it is used to detect, and can quantify, the amount of human blood in a single stool sample.
- an abnormal result suggests that there may be bleeding within the gastrointestinal tract that requires further investigation.
- those with an abnormal result are then invited for further testing via a colonoscopy.
What is epistemology
Epistemology involves knowledge claims and what we can assert about the world around us and the limits of what can be known.
What is the difference between the two stances of epistemology, positivism and interpretivism
Positivism is about explanation (need for statistical generalisation etc)
•Interpretivism is about exploring and understanding (need for depth and context etc) – Weber’s Verstehen and ‘meaningful understanding’
Is qualitative research a positivistic or interpretivism stance of epistemology
Qualitative research is linked to non-positivistic views about knowledge.
What is methodology
Methodology is the study of methods and refers to the strategy or approach to research.
Generally thought of in terms of either:
•Quantitative
•Qualitative
What is a method
Method is a specific technique (or set of techniques) for data collection
•Informed by methodology (which is shaped by epistemology)
•Within quantitative methodology – questionnaire survey, experiment etc
•Within qualitative methodology – interviews, observation, documentary analysis
What is positivism? (In terms of qualitative research)
Positivism is based on concepts such as:
•objectivity (i.e. the objective reality of the physical, external world)
•scientific method
•Empiricism
Positivism is about explanation (need for statistical generalisation etc)
post-positivism emerged, retaining scientific method but offering, as in the work of Popper, the idea of testable hypotheses / empirical falsification.
What is interpretivism
Interpretivism is about exploring and understanding (need for depth and context etc) – Weber’s Verstehen and ‘meaningful understanding’
Not a single philosophical approach but linked to several:
•Hermeneutics – interpreting unique human activity
• Phenomenology – how individuals experience the world
- the assumption is that social reality can only be understood through social constructions such as language, consciousness and shared meanings and understandings.
- interpretive research does not predefine variables, but explores human sense-making in naturalistic settings.
- often explicitly attempts to explore action / behaviour from the point of view of those being research (ie. not imposing a view / set of questions / assumptions on the group being researched).
What is Hermeneutics
- interpreting unique human activity
What is Phenomenology
how individuals experience the world
Which form of epistemology research does quantitative research belong to
-based on positivism
Quantitative methodology
•Emphasises quantification in collection and analysis of data
•Deductive approach – theory testing
•Based on positivism
•Views social reality as external and objective
Which form of epistemology research does qualitative research belong to
-based on interpretivism
Qualitative methodology
•Emphasising words, rather than numbers
•Inductive approach – generating theories (does not claim ‘truth’ status)
•Based on interpretivism – understanding the ways in which individuals and groups interpret their world
Give the 4 characteristics of qualitative research
- natural context
- non manipulative
- researcher as an instrument as they interpret it
- subjectivity and reflexivity of the researcher
Natural context – occurs in ‘natural’ settings
•Places where people interact (GP/dental surgery, classroom, street corner etc)
•Study of inanimate objects (how health care/policy is developed or organised)
•Non-manipulative – study situations/objects ‘intact’
•Researcher observes, interviews, records, describes settings ‘as they are’
•Researcher as ‘instrument’ – researchers engages in a situation and attempts to make sense of it
•Data collected through human observation
•Data interpretation through human perceptions
•‘Subjectivity’ / reflexivity of researcher – insights, experiences, perceptions of researcher are important part of the study
Give the 6 types of analysis of qualitative research
- narrative ;states context of accounts given is just as important as how and why stories are told, analysis often imposes structure and temporality e.g Labovian analysis, Reissman and plot
- interpretative phenomenological analysis (IPA) ; emphasis is on the lived experience of the participants and seeks depth of meaning of them
- grounded theory ;inductive analysis that seeks to generate new from rigorous series of coding stages and processes (constant comparison, open/axial coding, deviant case analysis)
- conversation ;recognises fundamental linguistic importance to interactions and need to analyse different forms of these
- thematic ;5 stages process of understanding data and then moving from codes to themes
- framework ;deductive analysis often relying on pre-determined aims and requirements. Emphasises transparency ability to multiple code
What are the functions of the stomach
- store and mix food
- dissolved and continue digestion
- kill microbes
- secretes proteases
- secretes intrinsic factor
- activate proteases
- lubrication
- mucosal protection
- regulate emptying into duodenum
Which parts of the stomach is gastrin secreted
- the anthrum of the stomach
- the enteroendocrine cells secrete gastrin
How much gastric acid (HCl) is secreted each day
- approx 2 litres
- requires energy
- by parietal cells
How is gastric acid secretion regulated
-by the stomach, brain and duodenum
1 parasympathetic neurotransmitter (ach +)
1 hormone (gastrin +)
2 paracrine factors (histamine +, somatostatin -)
2 enterogastrones (secretin -, CCK-)
Give the different phases involved with gastric acid secretion
Turning it on
- cephalic phase
- gastric phase
- proteins in stomach
Turning it off
- gastric phase
- intestinal phase
Explain the cephalic phase of gastric acid secretion
- the sight, smell, taste and chewing of food
- activates the parasympathetic system causing the release of acetylcholine
- acetylcholine acts directly on parietal cells causing release of HCl
- acetylcholine triggers the release of gastrin and histamine which act on parietal cells causing the release of HCl
Explain the turning on gastric phase of gastric seceretion
- food in the stomach causes gastric distension
- the presence of peptides and amino acids causing release of gastrin
- gastrin causes release of histamines
- gastrin and histamine act directly on parietal cells causing release of HCl
- protein in the stomach act as a buffer and mop up H+ ions increasing the pH
- increase in pH causes decreased secretion of somatostatin and so more parietal cell activity so more HCl
Explain the turning off phase of gastric acid secretion
- low pH in the stomach (high H+ ions) inhibits gastrin secretion
- this inhibits histamine release as no gastrin
- low pH stimulates somatostatin release which inhibits parietal cells activity
Explain the turning off intestinal phase of gastric acid secretion
- short and long neural pathways reduce release acetylcholine release
- duodenal distension, low duodenal pH, hypertonic duodenal contents and the presence of amino acids and fatty acids cause the release of enterogastrones
enterogastrones include
- secretin which inhibits gastrin release and promotes somatostatin release
- cholecystokinin (CCK)
What is an ulcer
-a breach in a mucosal surface
Give 4 causes of ulcers
- helicobacter pylori infection
- drugs (non steroidal antiinflammatory drugs NSAIDS)
- chemical irritants -alcohol and bile salts
- gastrinoma
How does the gastric mucosa defend itself
- alkaline mucus
- tight junctions between epithelial cells
- replacement of damaged cells
- feedback loops
What does gastrin do and which cells secretes it
- it triggers the release of histamine
- it acts directly on parietal cells causing the release of HCl
- acts on gastrin receptors on parietal cells
- it is secreted by enteroendocrine cells (G cells)
What does somatostatin do and which cells secretes it
- it inhibits parietal cells from releasing HCl
- produced by D cells (delta cells)
What does histamine do in gastric acid secretion and which cells secretes it
- it acts on parietal cells to cause the secretion of HCl
- it acts on the H2 receptors on parietal cells
- it is secreted by enterochromaffin-like cells (ECL)
What does secretin do and which cells secretes it
- regulates water homeostasis
- inhibits gastric acid production
- produced by S cells in the duodenum (and sometimes jejunum)
How does helicobacter pylori cause peptic ulcers
- it lives in gastric mucus
- it secretes urease which divides urea into CO2 and ammonia
- ammonia combines with H+ in stomach to form ammonium which damages gastric epithelium
- damage causes an inflammatory respond which further reduces mucosal defense
-ammonium, secreted proteases, phopholipases and vacuolating cytotoxin A all also damage gastric epithelium
How do non steroidal anti inflammatory drugs (NSAIDS) cause peptic ulcers
- mucus secretion is stimulated by prostaglandins
- cyclo-oxygenase 1 (COX1) is needed for prostaglandin synthesis
- non steroidal anti inflammatory drugs inhibit cyclo-oxygenase 1 (COX-1)
- so there is reduced mucosal defence so ulcers can form
How can bile salts cause peptic ulcers
- a duodeno-gastric reflux can cause regurgitated bile in the stomach
- the bile can strip away the mucus layer
- so a reduced mucosal defence
How would a helicobacter pylori infection be treated
with triple therapy
- proton pump inhibitor (to reduce H+ in stomach) e.g omeprazole, lansoprazole, esomeprazole
- antibiotics (to kill bacteria) e.g clarithromycin, amoxillin, tetracycline, metronidazole
- non steroidal anti inflammatory drugs (prostaglandin analogues) e.g misoprostol
What do H2 receptor antagonists do and give two examples of them
- they prevent histamine binding to the H2 receptors on parietal cells
- cimetidine and ranitidine
Since pepsin is only active at low pH preferentially pH 2, can it be reactivated in the small intestine
-irreversible inactivation in the small intestine by HCO3-
How is pepsin produced
- pepsinogen is released by chief cells
- pepsinogen is converted by HCl into pepsin
- pepsin also converts pepsinogen into pepsin too
- optimal pH is 2 or lower
- conversion of pepsinogen to pepsin is pH dependent
Is pepsin essential for protein digestion
- no
- protein digestion can occur if the stomach is removed
- it accounts for only 20% of total protein digestion
How much of total protein digestion does pepsin account for
-20%
What does pepsin do
-breaks down collagen in meat and helps shred meat into smaller pieces increasing surface area for digestion
What is the volume of an empty stomach
-50ml
Which parts of the stomach undergo receptive relaxation
-the smooth muscle in the body and fundus of the stomach
What is receptive relaxation
- mediated by the parasympathetic nervous system acting on the enteric nervous system
- through the afferent input of the vagus nerve
- nitric oxide and serotonin released by the enteric nerves also encourage relaxation
Describe the process of gastric motility
-peristaltic waves begin in the gastric body (weak contraction of the body)
-more powerful contraction in the gastric anthrum
-pylorus closes as the peristaltic wave reaches it
-little chyme enters the duodenum
-anthral chyme forced back towards the body of the stomach
-
What is the basic electrical rhythm for the stomach muscle contraction
- 3 per minute
- determined by interstitial cells of cajal in the muscularis propria
- depolarisation waves transmitted through gap junctions to adjacent smooth muscle cells
What increases the strength of peristaltic contractions
- gastrin
- gastric distension (mediated by mechanoreceptors)
What decreases the strength of peristaltic gastric contractions
- duodenal distension
- increased duodenal luminal fat
- increased duodenal osmolarity
- decreased duodenal pH
- increased sympathetic nervous system action
- decreased parasympathetic nervous system action
What happens if the capacity of the stomach is greater than the capacity of the duodenum
- dumping syndrome
- caused by the overfilling of the duodenum with a hypertonic solution
- symptoms are vomiting, bloating, cramps, diarrhoea, dizziness, fatigue, weakness, sweating and dizzness
Do secretions of enterogastrones increase or decrease gastric emptying
- decrease gastric emptying
- increase in secretion of enterogastrones is due to duodenal distension, decrease of duodenal pH and other duodenal factors that show food is in the duodenal so this would signal the stomach to not empty anymore into the duodenum
What is gastroparesis
-delayed gastric emptying
What can cause gastroparesis
- idiopathic
- autonomic neuroathies (e.g Diabetes mellitus)
- abdominal surgery
- parkinson’s disease
- multiple sclerosis
- scleroderm
- amyloidosis
- female gender
- drugs
What are the symptoms of gastroparesis
- nausea
- early satiety
- vomiting undigested food
- GORD
- abdo pain/bloating
- anorexia
Give some drugs that can cause gastroparesis
Gastrointestinal agents
- aluminium hydroxide antacids
- H2 receptors antagonists
- proton pump inhibitors
- sucralfate
Anticholinergic medications
- diphenhydramine (Benadryl)
- opioid analgesics
- tricyclic antidepressants
Miscellaneous
- beta-adrenergic receptor agonists
- calcium channel blockers
- interferon alpha
- levodopa
Is gastric motility and emptying regulated by the same factors that regulate HCl production
Yes
What is Meckel’s diverticulum
- a remnant of the embryonic attachment of the midgut loop to the yolk sac
- usually a blind-ended diverticulum about 1 meter from the end of the ileum
Where is Meckel’s diverticum
-usually about 1 meter from the end of the ileum
How is the superior mesenteric artery related to the duodenum
-the superior mesenteric artery runs over the top of the 3rd part of the duodenum
Gives the veins that drain the foregut, midgut and hindgut
Tbc
What forms haustrations
-the bulges of the inner circular muscle under the longitudinal muscle that have fused into three taenia coli till the recto-sigmoid junction
What does the appendicular artery supply and where is it
- supplies the appendix
- it runs along the appendix
What do the epiploic appendages (appendices epiploicia) signify?
-where blood vessels penetrate the muscles of the bowels to supply the mucosa and submucosa
Where does the superior rectal artery run
-enters the pelvic cavity posterior to the rectum and lies in the mesorectum between the rectum and sacrum
Do peyer’s patches have a capsule
No
What does the liver do
- detoxification (filters and cleans blood of waste products)
- immune functions (fights infections and diseases)
- synthesis of clotting factors proteins, enzymes, glycogen and fats
- production of bile and breakdown of bilirubin
- energy storage (glycogen and fats)
- regulation of fat metabolism
- ability to regenerate