Unit 3: gut health Flashcards
What is transient gastroenteritis?
Self resolving infection resulting in inflammation of the enteroendocrine (absoprtive cells) in the small intestine
What is the pathophysiology of a clostridium difficile infection in the gut?
Is an opportunistic pathogen - may be found normally within the flora but is kept at lower levels as it is outcompeted by other bacteria
When competition decreases, numbers spike and colonises the blood stream.
Damage to mucus membrane of the gut results in a pseudomembrane - rbcs and wbc, loss of intestineal membrane hence lots of fluid lost into the large intestine.
Is spore forming.
How to test for C.Diff?
Stool test
To identify toxins, uses antibodies to show up on an agglutination test
Gram-positive bacillus bacteria
Clinical sign - three watery stools within 24 hours
What are the key immune components in the gut?
Microfold cells - invagination in basal membrane, allow dendtric cells to sample gut lumen and rapidly present to T cell
Peyers matches - GALT in the ileum
Paneth cells in the SI - release antimicrobial peptides
Gut microbiome - outcompete other pathogens
Stomach - low Ph denatures enzymes
Mucus barrier - reduces attachement and invasion
What is the vomiting reflex?
Brain nuclei that result in the uncontrolled response of vomitting.
Chemical trigger zone - activated by foreign substances in blood stream, or release of seratonin by damaged cells triggering the vagus nerve.
Relay to the vomitting centre - can also be activated by higher brain centre by thinking something is disgusting or by bad smell etc or emotional overwhleming
Results in contraction of abdominal muscles and dipahragm to increase intraabdmonial pressure, increased salivatoin for lubraication and relaxation of the diaphragmatic sphincter resulting in expulsion
What is crohns disease? What is its biology and symptoms?
A primary autoimmune condition - results in chronic inflammation of the GUT. Damages the mucosa, often resulting in ulcers.
Abdominal pain
Blood in faeces/urine
Nutrients deficiency
Vomitting
What are the treatments for crohns disease?
Ileocolic resection - part of small intestine removed
Colonectomy - part of colon removed
Both of these surgeries normally require a stroma bag afterwards
Management: NSAIDS (with PPI), corticosteroids to reduce inflammation, immunosuppressants such as methotrexate
Encourage a liquid diet
Ilidumab - TNFalpha inhibitor
How is an infection managed in a hospital?
DIPCT - may contact local authority and HPA depedning on control and what illness
Isolate patients
Hygeinic practise
PPE
Controlling flow of air ventialtion and people considered infectious wards and what patients are immunocompromised
Microbial testing - key variables to consider
Where should the sample be taken from: blood, faeces, urine example
Is the patient able to produce this sample
Do we have any clues from sysmptoms if so should testing by more specific e.g antibodies for one pathogen or should testing by more generalised such as grown on culturing agar
Will we have enough of the sample to test or should it be replicated before testing begins
How long wil it take to get results
Should I start treatment before I get results
What tests differentiate between key types of Staphylococcus and streptococcus?
Staphy - purple clumps strep - purple clumps
Staphy - catalase positive
aureus - coagulase pos
epidermis - coagulase negative
Strep - coagulse and catalse negative
Staphylococcus aureus - manitol postive so agar changes from red to yellow
How is diahorrea managed?
Oral rehydration therapy
- increase levels Na+ and K+, increase their absorption from the gut, water will follow by osmosis
Zn supplements - increases the number of brush border enzymes and help regenerates the epithelium
May require IV fluids to prevent dehydration
How is vomitting managed?
IV fluids to prevent dehydration
Antimetics - inhibit the vommitting centre, often seratonin/dopaminergic antagonists prevent activation of the vagus nerve
may also be given sedatives to prevent the increase in intrabsominal pressure
May be givens steroids to increase the rate of gastric emptying
What are the main gut infections in the world?
How are they treated?
Bacteria: E.coli, cholera
Viral:
What are the key processes of secretion in the gut?
Water and electrolyte levels are regulated in the large intestine mainly
Chloride passes into the cell and is actively transported out into the lumen this requires cAMP.
Some sodium and magneisum may follow this movement down a chemical gradient but most is back out the basolateral membrane by active transport
A small amount of water can then enter the lumen by osmosis
What is the pathophysiology of E.coli in the gut?
Spread by contaminated food and water from faeces - increased risk if work with rodents or sewage
