Blocks 2 and 3 Flashcards
What are the relevant virulence factors for Streptococcus pneumoniae? KEY EXAM Concept - One example of impedin, aggressin, and modulin to illustrate pathophysiology of Sp Pneumoniae
The Capsule. Most important. Impedin as it confers resistance to phagocytosis, allowing more bacteria to survive and multiply. And 90 capsule types mean few opportunities for acquired immunity.
Capsule also generates the immune response (aggressin). Adhesin proteins mediate adherence.
Cell lysis acts as an agressin. Cell wall components peptidoglycan, techoic acid, lipotechoic acid generate vigorous local inflammatory response. Pneumolysin is cytotoxic to endothelial cells via pneumolysin. Together they eliminate the muco-cilliary escalator and disrupt alveola-capillary boundary, facilitating transfer to bloodstream.
Lysis also acts as modulin - pneumolysin is cytotoxic to immune cells, and peptidases interfere with immune signalling.
What are the names and gram stain appearance of the 4 most common pathogens commonly associated with respiratory infections?
Strep. pneumoniae - Gram positive diplococci
Haemophilus Influenzae - Gram negative coccobacilli
Moraxella Catarrhalis - Gram negative diplococci (Upper respiratory tract)
Neisseria meningitidis - Gram negative diplococci (Lower respiratory tract)
How can Strep. Pneumonia lead to baceraemia and meningitis?
Once infection established, partial cell lysis releases pneumolysin. Cytotoxic to endothelial and immune cells, breaks down barrier between alveoli and capillaries. Haematogenous spread (bacteraemia). Sp has a tropism for CNS,
What are the Gel and Coombes classifications of immunopathologies?
What is the Difference between sex and gender
sex: male and female biology; chromosomes, hormonal profiles, sex organs
gender: social and cultural construction of male and female and masculinity and femininity
What impact does the delineation of sex and gender have on illnesses?
illnesses are often distributed along gender lines for biological and social reasons
there are genuine biological differences in disease prevalences (these may be obscured by past epidemiological research, e.g. research tended to be done on men rather than men and women)
there are genuine differences in health-seeking patterns; women more likely to report
E.g. breast cancer research done on women only, but men can get breast cancer too (1% of cases are in men); “wear pink for breast cancer” - how would men feel then?
What are the 5 criteria for medicalisation?
condition must be biologically plausible
Must speak to preoccupation/anxiety in society
Must have an authority in medicine
Must have an acceptable method of diagnosis
Must have an acceptable method of treatment
What are the three models of disability?
Medical, social, biopsychosocial
medical model
disability is a medical problem
policy aids rescue of the disabled
can result in devaluing the lived experience of the disabled
Christopher Reeve was an advocate, saying living with a disability was terrible; this caused debate as not all disabled people agree
social model
“disability is in the eye of the beholder”
opposite model to the medical model
based on principle of equivalence; disabled people should have same opportunities as able-bodied
destigmatises disability
current federal government uses this model (trying to improve access for disabled people in the workplace)
e.g. Graeme Innes vs RailCorp over unintelligible announcements; if think it is ridiculous that RailCorp argued the case, then you believe in the social model
biopsychosocial model
recognises that bodies suffer in individual ways
model based on principle of respect for these differences
prepares for, recognises and responds to fluctuations in physical and emotional capacity
recognises that the internal and physical world of the person needs appropriate healthcare provision
national disability insurance scheme (NDIS) follows this policy model
Why are the poor sicker?
The poor are more likely to have a chronic illness, and are more likely to be severely disabled; possible explanations include:
lack of health services (tend to be fewer in poorer areas)
poorer health hardware (e.g. lack of refrigeration means range of health promoting choices limited)
environments conducive to ill-health (poorer quality food, more exposure to env. pollutants)
Why are sick people (chronic illness) more likely to be poor?
downward drift (happens to even the richest people that become chronically ill; people with chronic illness may find it harder to keep down a job because of the illness, and thus may lose their income earning capacity; relationships may come under threat, again reducing the income the individual has)
health care costs (it costs money to be ill and to be constantly accessing services)
need to pay ongoing attention to one’s physical self
become embroiled in health system and possible worker’s compensation
expenditure of money, loss of income
loss of many of the external attributes of self that one once had
Endocrine histology - Cells and function
What is Procreative autonomy? Example?
Definition: to have control over one’s reproductive capabilities; the freedom to choose whether or not to have children
development of the COCP:
reinforced the view of sexual pleasure as something to be enabled (prior to this, masturbation was “self-abuse” and “not biologically healthy”)
allowed sex and reproduction to be decoupled
became a tool to support the evolving autonomy of middle-class women
What factors do you consider when describing a tumour?
Site
Size
Shape
Surface
Margins
Colour
Consistency
Capsule?
MI at the different stages
One Day
Macro - Subtle changes, dark mottling
Micro - Contraction bands, coagulation necrosis, haemmhorage, scattered neutrophils
Two Days
Macro - Mottled with yellow/tan infarct centre.
Micro - Coagulation Necrosis, Neutrophils
One Week
Macro - Hyperaemic border, central yellow softening
Micro - Disintegration of myofibres (borders disapearing), dying neutrophils, macrophages.
Two Weeks
Macro - Maxmially yellow/tan and soft, depressed infarct borders
Micro - Phagocytosis, Granulation tissue (angiogenesis and ECM), early fibrosis (lots of collagen and spindle cells)
Two Months
Macro - White scarring
Micro - Dense, collagenous scar
Asbestos
What is it?
Modifiers?
Complications?
Pneumoconiosis - Restrictive lung disease caused by inhalation of dust.
Modifiers - Duration and length of exposure, amount of retained dust, small size, shape of particles (type of asbestos), solubility of particles, Additional Irritants, preexisting lung disease.
Complications - Pleural plaques, asbestosis, pleural effusions, cancer (lung, mesothelium, other)
Study Design Table
