Acute inflammatory diseases

Question 1

Describe appendix anatomy

Answer 1

extension of LI
mesoappendix connects to ileum 
microscopically similar to colon 
young people have lining interspersed with lymphoid follicles 
mucosa, submucosa, muscularis, serosa

Question 2

what are the causes of luminal obstruction in the appendix

Answer 2

foceal, gallstone, tumour, worms

Question 3

describe the pathogenesis of appendicitis starting from luminal obstruction

Answer 3

-> mucus increases pressure -> mucosal ischaemia -> mucosal injury -> acute mucosal inflammation -> 2ndry bacterial invasion -> spread inflammation transmurally

Question 4

what are the 3 stages of appendicitis

Answer 4

early acute,
acute suppurative
acute gangrenous

Question 5

what happens in early acute appendicitis

Answer 5

neutrophilic exudate in mucosa

mild inflammation

Question 6

what happens in acute suppurative appendicitis

Answer 6

transmural inflammation (tense, thick wall)
mucosal ulceration + purulent exudate in lumen (viscous cloudy fluid)
inflamed serosa and with fibrinopurulent exudate, microabscesss (pathcy, pale)
hyperaemia

Question 7

what happens in acute gangrenous appendicitis

Answer 7

necrosis extends to muscularis externa because neutrophils -> enzymes + free radicals
rupture + acute peritonitis

Question 8

clinical features of appendicitis

Answer 8

pain, low fever, nausea, vomiting, anorexia, neutrophilia
difficult to diagnose in old/young
many differentials

Question 9

how does pain progress in appendicitis

Answer 9

starts as vague cramps progresses to be localised

Question 10

complications with perforation in appendicitis

Answer 10

spread faeces into peritoneal cavity

local peri-appendical abscess or general peritonitis

Question 11

complications with general peritonitis in appendicitis

Answer 11

ileus (temporary lack of the normal muscle contractions of the intestines)
cause temporary arrest of peristalsis and abdominal distention
incrrease fever, tenderness + rigidity

Question 12

complications of septic shock in appendicitis

Answer 12

gram negative bacteria from GIT enter bloodstream
bacterial death releases lipopolysaccharides which cause endothelial injusry and cytokine release which causes widespread vasodilation
systemic septic shock -> myocardial injuriy + lowering BP

Question 13

meninges anatomy

Answer 13

dura + arachnoid + pia mater

subarachnoid space circulates CSF therefore infection sprad rapidly

Question 14

ROUTE OF cns INFECTION

Answer 14

haematogenous, direct traumatic implementation, local extension of infection or from pNS

Question 15

damage from CNS infection caused by …

Answer 15

direct infectious injury, roxins, inflammatory response, immune mediates mechanisms

Question 16

causes of APM

Answer 16

microorganisms 
neonates = e.coli + b streptococci
infants = strep pneumoniae
adolescents = neisseria meningitidis
elderly strep pneum. + lysteria monocytogenes

Question 17

symptoms apm

Answer 17

systemic infection, headache, photophobia, irritability, cloudy consciousness, bulging fontanelle, neck stiffness

Question 18

how is apm diagnosed

Answer 18

spinal tap = gluid has high nuetrophil count, high proteins and low glucose

Question 19

what are the complications of apm

Answer 19

cerebral oedema and increased ICP
infection spread to brain parenchyma causing focal cerebritis
exudate can ogranise causing adhesions to teh meninges and the CSK blockes = hydrocephalus
compress cranial nerve causing palsies
affect blood vessels causing thrombosis and infarctions
sepsis

Question 20

what is meningococcaemia

Answer 20

blood infection from meningitis
bacterial replicates releases endotoxins which interact with macrophages to release cytokines and free radicals
damage vascular endothelium and platelet deposition causes vasculitis and petechial haemorrhage
multiorgan shock

Question 21

describe the macroscopy of meningitis

Answer 21

brain swollen + leptomeninges are congested
purulent exudate over cerebral hemispheres + brain base
oedematous white matter
ventricular enlargement