GI tract Flashcards
What does the upper Gi tract include?
Mouth, oesophagus and stomach
What does the lower Gi tract include
Small Intestine – duodenum,jeunum, ileumLarge Intestine – caecum,colon, rectum
What are the disorders of the stomach?
-Peptic Ulcers (duodenal or gastric)
-Gastrinoma
-Vitamin B12 Deficiency
What are the disorder of the pancreas
-Acute and Chronic Pancreatitis
-Cystic Fibrosis
-Diabetes
- Cancer
What is gastric ulcer, how is it caused and what are the symptoms ?
Inflammation disorder of the gastric mucosa
It is caused by Nsaids which inhibit the enzyme cyclozygenase which is involved in the synthesis of inflammatory Prostaglandins , alcohol or infection
Symptoms :Ab pain,Reflux, Nausea,Loss of appetite and vomiting
What is peptic ulcer disease
1.Break or ulceration in mucosal lining of the lower oesophagus, stomach, or duodenum.
2.Can lead to mucosal haemorrhage
What are the GIT lined with?
Mucosa
the mucosa contains epithelia cells - absorbs and secrete mucus and digestive enzymes
Lamina propria- has blood and lymph vessels
Muscular mucosa has layer of smooth muscle that contracts and breaks down food
What are the 4 regions of the stomach
- Cardia
2.Fundis
3.Body - Pyloric antrum (at the end of the stomach there is a pyloric value that closes when eating so the stomach digest)
What cells do the parts of the stomach secrete?
- Cardia has Foveolar cells which secrete mucus made from H20 + Glycoproteins
- Fundis and body have parietal cells secreting HCL and chief cells secreting pepsinogen to digest proteins
3.Antrum has G cells secreting gastrin in response to food entering the stomach
what are the Laboratory Investigations and treatments for Peptic Ulcers?
Urea Breath Test
Helicobacter pylori IgG Antibody
Treatment:
Can give H2 receptor antagonists or proton pump
What happens in the duodenum Brunner gland?
In the duodenum the Brunner gland secretes mucus in high bicarbonate ions with hCl floating the stomach and duodenal mucosa would be digested if not for the mucus coating of the wall and the bicarbonate neutralising the acid
Why are the walls the stomach thicker than the duodenum?
Because they come into contact with acid
When does gastric ulcer pain and Duodenal ulcer pain happen?
gastric ulcer pain - when eating
Duodenal ulcer pain - not eating leads to weight gain
What happens in Zollinger Ellison Syndrome?
Elevated gastrin and acid production, peptic ulcer- leads to ulcer
Gastrinoma secretes abnormal amount of gastrin Increase in gastrin = parital cells release excess hcl acid leading to ulcer in the first portion of the duedoum
Gastrinoma is a tumour
It is tested by endoscopy to see the ulcer
Treatment : antibiotics for H. pylori infection
What are the symptoms of diabetes ?
- Frequent urination at night
2.Tiredness
3.Loss of weight
4.Utis
5.Cut and wounds take longer to heal
6.Blurred vision
7.Fruity smelling breath
What is the Classification of Type 1 diabetes mellitus
1.Type 1 (5 – 10% patients) Autoimmune destruction of β cells No insulin production Specific autoantibodies measured
2.LADA – Latent autoimmune diabetes (>30 years) –subset of Type
3.Monogenic Diabetes (may be misclassified as Type 1 or Type2 DM) – very small number Neonatal Diabetes (NDM)
What is the test for diabetes?
Glutamic Acid Decarboxylase Autoantibodies test (GAD antibodiestest) is used to help discover whether someone has either type 1diabetes or Latent Autoimmune Diabetes of Adulthood (LADA
What are the diabetes complications?
*cardiovascular disease (CVD)
* kidney disease (most common cause ofESRD)
* retinopathy
* neuropathy
* depression
* sexual dysfunction
What is t2d treatment?
Metformin-Suppress liver gluconeogenesis
Sulphonlyurea-Stimulate insulin release by closing K sensitive ATPase channels
pioglitazone-Bind to PPAR alphaand gamma, increasetissue sensitivity to insulin
What is the Clinical diagnosis of Malabsorption?
History (age, weight loss, infections, alcoholconsumption)
2.Stool Appearance – Steatorrhoea – ?3.Endoscopy
4.Routine blood tests
5Investigative tests
Diseases of the Small Intestine?
Crohn’s Disease ,Coeliac Disease, Bile Acid Malabsorption and Neuroendocrine Tumours
Diseases of the Large Intestine
Ulcerative Colitis ,Irritable Bowel Syndrome,Diverticular Disease, Colo-Rectal Cancer
what happens in direct Elisa
Antigen binds to surface
2. Antibody recognises antigen
- Antibody is conjugated to an enzyme
- Non-bound antibody-enzyme is washed off
- Enzyme converts chemical(“chromogenic substrate”) into a coloured form which can be measured
- The more antigen in the sample thenthe greater the amount of antibodythat binds therefore they greater theenzyme activity hence coloured dyeproduced faster
One antibody
what happens in indirect Elisa?
Immobilise a purified viral protein on the surface
- If the sample contains antibodies that recognise that protein they will bind
- An antibody that recognises antibodies is conjugated to an enzyme and added
- Non-bound antibody-enzyme is washed off
- Enzyme converts chemical (“chromogenic substrate”) into a coloured form which can be measured
- The more antibody that recognises the viral protein in the sample then the greater the amount of antibody/enzyme conjugate that binds therefore they greater the enzyme activity hence coloured dye produced faster
2 antibodies
what happens in sandwich Elisa
- Immobilise an antibody that recognisesthe antigen on a surface
2.If the sample contains the antigen it will bind - An antibody that recognises the antigenat a second site conjugated to anenzyme and added
- Non-bound antibody-enzyme is washedoff
Enzyme converts chemical(“chromogenic substrate”) into acoloured form which can be measured - The more antigen in the sample thenthe greater the amount ofantibody/enzyme conjugate that bindstherefore they greater the enzymeactivity hence coloured dye producedfaste
