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57 Cards in this Set
- Front
- Back
3 small bowel diseases which show dysregulation in their immune system
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IBD
coeliac primary immune def |
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name some mucosal tissues of the human body
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GI tract (salivary gglands- anal canal), resp tract, uro-genital tract, mammary glands
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name some secondary lymphoid tissues
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remember: peyer's patches in small intestine (ileum)
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what specialised epithelial cells are present in Peyer-s patches (ileum)
- what are their characteristics |
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what are the function of M cells at the epithelial surfaces of Peyer's patches?
- by what transport mechanism - what happen's on the lamina propria side? |
M cells in close proximity to underlying immune cells.
TRANSPORT ANTIGENS--->lamina propria side: co-stimulatory signals |
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apart from M cells in Peyer's patches of the ileum, what other cells in the epithelium are important for the gut's immune defence
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& CD8 killer T cells
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villi (in addition to peyer's patches) also contain immune cells.
- which are in the lamina propria |
CD4, mac, mast, dendritic, plasma cells
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how are activated effector T cells sent to their destined place in the lamina propria of the small intestine?
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T cells 'homed' to peyer's patched → dendritic cells present antigen → T cells activated → lymph →blood → appropriate chemokines & receptors attract effector T cells to gut.
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which receptor do activated effector cells bind to on the endothelium of gut capillaries to enter the villi where they will act
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MadCAM-1
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which Ig predominates in the humoral intestinal response produced by plasma B cells
- role |
80% IgA- AGGLUTINATION & NEUTRALISATION at mucosal sites (also at other mucosal tissues)
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Intraepithelial Lymphocytes (IELs): T cell (CD8) expression of which integrin anchors them in the epithelium
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αE:β7
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what cell type are the majority of IELs? (intraepithelial lymphocytes)
- how do they respond to epithelial cell infection |
CD8+ Killer T cells
- kill infected cell via perforin/granzyme & Fas-dependent pathways |
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in mucosal hyperresponsiveness, T cells show a higher level of activation & a stronger response where there shouldn't be.
- what molecules are absent to prevent dendritic and T cell maturation? |
chemokines
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IgA def is a primary immunodef, what disease does is predispose to
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coeliac's disease
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food allergy demonstrates what type of hypersensitivty
- cells involved? - common symptoms |
IMMEDIATE type 1 IgE-mediated
cross-link on MAST cells - vomiting (intestinal contraction) - diarrhoea - puritis (itching_, urticaria (itching), anaphylaxis (rare) : from wide haematogenous dissemination |
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which enzyme is present in coeliac's disease that modifies gluten so it can be presented to CD4 T cells (MHCII) causing an autoimmune response?
- what type of hypersensitivity reaction does it show |
tTG (tissue transglutaminse)
can be used for dx - DELAYED type 4 hypersensitivity: Tcells & macrophages |
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how to dx (Ix's) for coeliac's disease
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BIOPSY
serology: IgA & tTG |
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2 types of autoimmune inflammatory hepatobiliary cirrhosis
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autoimmune hepatitis
primary biliary cirrhosis (? primary sclerosing cholangitis- suggested) |
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autoimmune hepatitis is a type of autoimmune inflammatory hepatobiliary cirrhosis...which shows loss tolerance against liver tissues
- which 3 serum antibodies can be detected on Ix |
antibodies to:
- nuclear antigens (ANA) - smooth muscle (ASM) - liver kidney microsomala antigens (LKM1) |
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PBC (primary biliary cirrhosis) is a type of autoimmune inflammatory hepatobiliary cirrhosis...showing chronic cholestatic LIVER disease with small & medium INTRAhepatic duct destruction.
- which serum antibody can be detected in high concs? |
IgG AMA (antimitochondrial ab's) 98% - M2 subtype
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only therapy for PBC
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UDCA (ursodeoxycholic acid)
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where's the control centre for energy homeostasis ( integrates neural & hormonal)
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hypothalamus
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what controls short-term satiation
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PEPTIDES produced in the STOMACH & GI tract
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what controls long-term body weight
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HORMONES
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which peptides controlling short-term satiation is released from the I-cells of the duodenum & jejunum
- in response to what - effect |
CCK in response to FAT & PROTEIN
seonsory --> hindbrain |
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which2 peptides controlling short-term satiation is released from the L-cells of the GI tract
- in response to what - effect |
1) PeptideYY (PYY) AFTER meals
-inhibits gastric emptying - satiation 2) GLUCAGON-LIKE peptide-1 (GIP-1) on INDEIGESTION - inhibits gastric emptying - satiation |
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which 2 peptides controlling short-term satiation is released from the OXYTINIC cells of the duodenum & jejunum
- in response to what - effects |
1) OXM- AFTER meal
- reduces appetite 2) GHRELIN - BEFORE meals - increases lipogenesis - hunger |
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2 hormones that communicate to hypothalamus to alter energy balance (increase energy burn)
- which cells release them - which malfunctions in obesity |
LEPTIN- adipose
INSULIN- pancreatic ISLET's of Langerhan's (endocrine) |
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what's the effect of reduced leptin levels (normally produced from adipose cells)
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mimics STARVATION = unrestrained appetite, increased fat deposition, reduced energy burn
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how does ORLISTAT work to reduce obesity
SE's |
inhibits pancreatic lipase
decreases triglyceride dig & absorption SHORT-term x. cramping, severe, diarrhoea |
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LORCASERIN is a new anti-obesity drug. which receptor does it antagonise
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5-HTc receptor antagonists
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histology of normal small bowel
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JEJUNUM- tallest villi, plicae circularis, goblet cells and crypts of Lieberkuhn
ILEUM- Peyer's patches, smaller villi & crypts, less prominent plicae, goblet cells |
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2 reasons why the bowel can become ischaemic
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OCCLUSION in mesenteric arteries:
- thromboembolism - atherosclerosis PERFUSION insufficiency: - shock - strangulation - drugs - hyperviscosity |
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which part of the GI wall suffers from ischaemia first (i.e. the most metabolically active)
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mucosa- can replace quickly
(muscle damage cannot replace quickly) |
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3 outcomes of ischaemic bowel
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- RESOLUTION
- FIBROSIS, stricture, chronic ischaemia, 'mesenteric angina' - GANGRENE, perforation, peritonitis, sepsis, death |
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what's Meckel's diverticulum
what ar ethe complications |
incomplete regression of vitello-intestinal duct, outpouching connected to umbilicus 2ft above ileocaecal valve:
X. bleeding, pain, perforation, divertilculitis |
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primary tumours of small bowel are rare:
- 3 types |
LYMPHOMOA- (MALTomo- Bcell derived)
CARCINOID- locally invasve, produce hormones CARCINOMAS- Chron's & coeliac disease, presents late. |
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secondary mets to small bowel are common:
from which 3 cancers |
ovarian
colorectal stomach |
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S&Ss appendicitis
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umbilical colic --> constant RIF
vomiting, constipation (or diarrhoea) tachycardic, shallow breaths, fever guarding peritonitis: wash-board rigidity, lay still ↑WCC & CRP |
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pathology of acute appendicitis
- specific loc of wall? |
acute inflammation- neutrophils, eosinophils...
MUCOSAL ulceration exudate, pus |
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3 complications of acute appendicitis
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perforation/ rupture --> peritonitis --> sepsis
abscess fistula |
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associations with coeliac disease
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HLA-B8
dermatitis herpetiformis childhood DM |
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pathological features of coeliac disease biopsy
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IELs (CD8) damage epithlial cells = villous ATROPHY
MALABSORPTION ↑IELs & ↑inflam cells in lamina propria PROXIMAL bowel worse |
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S&Ss coeliac disease
- intestinal - extra-intestinal -general |
STEATORRHOEA
abdo pain & bloating N&V mouth ulcers & angular stomatitis, glossitis (B12 def) ↓weight, fatigue, weak, anaemia, osteomalacia failure to thrive asymp! |
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5 complications of coeliac disease
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anaemia
GI T-cell lymphomas (rare) small bowel carcinoma gall stones ulceration & strictures |
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surgical criteria for bariatric surgery
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BMI>35 + co-morbidities
or BMI>40 achieved 5% weight loss tried ALL non-surgical Rx medically & psychologically stable non-smoker |
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3 types bariatric surgery
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BYPASS - reversible
BAND SLEEVE |
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common diseases causing malabsorption 6: CCCCBP
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COELIAC
CHRON's Chronic PANCREATITIS CIRRHOSIS Biliary obstruction/ cirrhosis = ↓bile Post-infection uncommon: (pancreatic ca, drugs, Short bowel syndrome) |
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S&Ss malabsorption
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diarrhoea, steatorrhoea
↓weight, faitgue anaemia (pallor, conjunctivae, ulcers, stomatitis, koilonychia) glossitis bleeding/ bruising (VitK def) oedema (↓protein) |
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Ix's for ?malabsorption
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FBC, coagulation (vit K), U&Es (hydration), LFTs (albumin), Ca (vit D def), COELIAC serology (IgA, tTG)
STOOL (fat, infection) ENDOSCOPY + BIOPSY RADIOGRAPHY- X-ray, USS, ERCP, CT, MRI |
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contraindications for artificial enteral feedin gsupport via NG/NG/PEG/PEJ
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ulcers
obstruction perforation fistulas facial injury |
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define acute and chronic intestinal failure
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gut not able to supply nutritional & hydrational needs
ACUTE <2wks: mucositis, post-chemo CHRONIC- short gut syndrome |
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causes of chronic intestinal failure
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SHORT BOWEL SYNDROME- iatrogenic or congenital
Vascular (ischmia) Neoplasia Dysmotility Severe CIRRHOSIS Iatrogenic |
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management of short bowel syndrome
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supportive/ symptom control -Rx: PPIs, loperamide, codeine
PARENTERAL feeding (long-term) TRANSPLANT (last resort) |
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some complications of parenteral feeding
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!!!PNEUMOTHORAX, puncture ARTERY, THROMBOSIS, SEPSIS!!!!
inappropriate use liver disease bone disease line fracture/ break psychosocial |
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clinical features of refeeding syndrome
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CV & resp FAILURE
bone marrow suppression- immunosuppression SEIZURES Metabolic disturbances: ↓K, ↓Mg, oedema, glucose metabolism shift, ↓vits |
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commonest western cause small intestinal obstruction
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adhesion (eg after surgery, prev intraperitoneal inflam)
or hernia |