Block 15 key things to learn Flashcards
What is the structure of the liver and what cells are in sinusoids?
Small hexagonal functions units called lobules- each lobule has a central vein surrounded by 6 hepatic portal veins and arteries.
Hepatic venule is connected to surrounding veins and arteries by sinusoids
Cells in sinusoids are-
kupffer cells- macrophages that break down RBC’s
Hepatocytes- line sinusoids and do most of liver functions
Stellate cells- quiescent and store vitamin A usually, but if liver damaged they become activated and secrete collagen scar tissue
What is hepatitis A?
Faecal-oral transmission
Incidence reducing, but increasing amongst MSM
Detected by- increased ALT increased bilirubin faecal HAV IgG anti-HAV IgM anti-HAV
Usually just an acute infection and recover
What is hepatitis B?
Transmission via body fluids
Sometimes becomes chronic- more likely to become chronic the younger you are when get it
See relationship between ALT and Hep B DNA
What is hepatitis C?
Transmitted by body fluids
HCV antibody blood test- takes 4-6 weeks to become positive or HCV PCR- take 10-14 days for result
10% mortality
Can treat with antivirals but often goes undetected until have cirrhosis
What is hepatitis E?
Most common cause of acute hepatitis
Passed on by contaminated pork
Low mortality unless pregnant or have chronic liver disease
What is crohns disease?
Macroscopic appearance-
serosal fat wrapping
cobblestone transverse ulcers
longitudinal serpiginous ulcers
Microscopic- crypt architecture preserved flat surface ulcer patch activity granulomas present fissuring ulcers transmural chronic inflammation
Complications- malabsorption, fistulas, anal lesions, perforation and haemorrhage and increased risk of bowel cancer
What is ulcerative colitis?
Macroscopic- length may be shortened normal serosa ulcers- flasked shaped inflammatory polyps
Microscopic- irregular surface diffuse crypt architectural distortion diffuse chronic inflammatory cell infiltrate rich in plasma cells
Crypt abscess is main histology
Symptoms- frequency and urgency, fever, cramping, abdominal pain, bleeding
Systemic implications of any IBD- arthritis, erythema nodosum, iritis, pyoderma gangrenous, sclerosing cholangitis, gallstones, renal stones and aphatous stomatitis
What is Addison’s disease, diagnosis and what is the treatment?
Insufficient production of cortisol mostly due to autoimmune disease.
Symptoms- hyperpiguentaion, weight loss, low blood pressure, nausea, vitiligo, constipation and abdominal pain
Diagnose by random cortisol level or 9am cortisol or by synacthen test.
Synachten test is when give synthetic ACTH which should stimulate cortisol release, then measure cortisol 30 mins later, if low level still then can diagnose Addison’s
Treat by giving hydrocortisone and fludrocortisone
What is cushings disease?
2 types- ACTH dependent or independent.
Dependent- most likely pituitary tumour
Independent- usually due to exogenous steroids
Symptoms- obesity, hypertension, muscle wasting, osteoporosis, moon face, increased diabetes and thrombosis risk
Diagnose by measuring cortisol levels or by overnight dexamethasone suppression test- should have low cotton levels but if high then can diagnose cushings
What is congenital adrenal hyperplasia
Glucocorticoids, mineralocorticoids and androgens all have same start point and if enzyme 21 hydroxyls which is needed for glucocorticoid and mineralocorticoid production is mutated then more androgens will be made instead.
2 forms- salt wasting- worse- less aldosterone and cortisol- many health problems
simple virilisation- more androgens so genital changes and early puberty
What are some antidiarrhoeal drugs?
Loperamide, codeine and co-phenotrope all act on mu opioid receptors to decrease peristalsis, increase transit time and increase water absorption
Octreotide reduces amount of water
Kaolin- helps thicken stool by acting as binding agent
What are some laxatives?
Bulk forming laxative- Isaphugula husk indigestible increases bulk of stool used if can't increase amount of fibre in diet
Osmotic laxative-
lactulose
synthetic sugar broken down by gut bacteria and releases osmotically active sugars to increase amount of water in stool
Stimulant laxative-
Senna and sennusoids
stimulates nerve endings in bowel and activates myenteric plexus to decrease time for water absorption and make sure there is more water in stool
Bisacodyl-
same but used to clear out for colonoscopy
What are IBD treatments?
Aminosalicylates- e.g. sulphasalazine Corticosteroids Immunosuppressants Biological therapies Helminth therapy Faecal microbiota transplant Small molecule drugs to modulate immune system Cytokine inhibitors
What are the layers of the adrenal gland and what comes from where?
Zona glomerulosa- outside- mineralocorticoids
Zona fasiculata- middle- glucocorticoid
Zona reticulata- inner- sex steroids
Medulla- catecholamines
What is shock and what are the different types?
Anaphylaxis Cardiogenic Hypovolaemic Neurogenic Septic
