Block 9 Flashcards
acute
recent
rapid onset
likely short duration
chronic
persistent
longstanding
risk factor
confers increased risk of disease development
predisposition
increased susceptibility to developing disease
pathogenesis
the mechanism resulting in clinical disease
premalignant
something that will probably transform into invasive malignancy
aetiology
the cause of the disease
disease
consequences of failed homeostasis
has potential to impair function
disease mechanism
the way in which homeostasis is disturbed
primary disease
arises spontaneously
not associated with or caused by previous disease or injury
secondary disease
follows and result from an earlier disease, injury or event
benign tumour
uncontrolled focal proliferation of well differentiated cells
malignant tumour
cancerous
invasive
has metastatic potential
types of necrosis
- coagulative
- colliquative / liquéfaction
- caseating
types of nuclear morphology
- pyknosis
- karyolysis
- karyorrhexis
karyhorrhexis
the destructive fragmentation of the nucleus of a dying cell whereby its chromatin is distributed irregularly throughout the cytoplasm
pyknosis
the irreversible condensation of chromatin in the nucleus of a cell undergoing necrosis or apoptosis (followed by karyorrhexis)
karyolysis
dissolution of cell nucleus, particularly during mitosis
hyperplasia
increase in cell number
hypertrophy
increase in cell size
atrophy
decrease in size and number of cells
metaplasia
conversion of one type of differentiated tissue into another tissue type
dysplasia
abnormal cytological appearance and tissue architecture
transdifferentiation
one cell type converting into another
hydrostatic pressure
drives fluid out of blood vessels and into other tissues (under physiological conditions)
colloid osmotic pressure
a function of protein concentration
pulls fluid back into blood vessels from tissues (under physiological conditions)
oedema
abnormal increase of fluid in interstitial tissue space
causes of oedema
- increased hydrostatic pressure
- decreased colloid osmotic pressure
- lymphatic obstruction
- sodium retention
- inflammation
haemorrhage
extravasation of blood due to vessel rupture
arterial thrombus
platelet-rich mass formed within arterial system
venous thrombus
fibrin- and erythrocyte-rich mass formed within venous system
embolism
solid, liquid or gaseous mass carried in the blood to a site distant from the point of origin
hyperaemia
an adaptive process involving an increase in blood volume in the microvasculature of a specific tissue in response to a change in the environment
congestion
- a maladaptive process involving an increase in blood volume in the microvasculature of a specific tissue due to impaired venous return from the area
- can be due to physical obstruction or physical insufficiency
shock
systemic hypoperfusion resulting in hypotension, cellular dysoxia, increased anaerobic respiration and lactic acidosis
types of shock
- cardiogenic
- hypovolaemic
- distributive / vasodilatory
- obstructive
types of distributive / vasodilatory shock
- anaphylactic
- neurogenic
- septic
liquid-filled dermal lesions
- blister
- vesicle
- bulla
- pustule
solid dermal lesions
- papule
- plaque
- nodule
- wheal
dermal lesions of altered colour
- macule
- patch
- naevus
- erythema
dermal scaling
shedding of cornfield layer
sometimes due to imbalance between production and loss
dermal callus
hyperplasia of epidermis following pressure or friction
dermal erosion
loss of superficial epidermis
dermal ulcer
loss of epidermis and papillary dermis
bruising
extravasation of blood into dermis
process of wound healing
haemostasis > inflammation > fibroplasia > epithelialisation > remodelling
virus
obligate intracellular parasite
nucleocapsid
viral genome contained in a protein capsule
virion
infective viral particle
naked enveloped viruses
- e.g. rotavirus, norovirus
- stable in face of environment stress
- kills host cell to spread so spreads easily
- generally survives the gut
enveloped viruses
- e.g. HIV, ebola, influenza
- must stay wet to remain infectious
- very sensitive to detergent because the envelope is a membrane
- can spread via budding instead of host cell lysis
types of viral proteins
- proteins to make progeny
- enzymes for genome replication
- proteins to interfere with host immune defences
on which characteristics are viruses classified?
- type of nucleic acid in genome
- polarity of genome
- replication method
stages of the infectious viral cycle
- attachment
- penetration
- uncoating
- replication
- assembly
- release
why are viral infections prevalent, persistent and problematic?
- few effective drugs due to resistance and innovation problems
- high mutagenic rates
- public health issues e.g. sanitation, decreasing vaccine uptake
- latent and persistent infections
- non-human carriers
influenza
- enveloped
- spiked
- ssRNA(-)
- aerosol droplet transmission
norovirus
- naked
- ssRNA(-)
- enteric transmission
hepatitis C
- enveloped
- ssRNA(+)
- percutaneous transmission (small chance of mucosal and perinatal)
- linked to HCC
HIV
- enveloped
- ssRNA(+) retrovirus
- percutaneous, mucosal and perinatal transmission
EBV
- type 4 HHV
- enveloped
- dsDNA
- associated with Hodgkins lymphoma and Burkitts lymphoma
- salivary transmission
methods of viral transmission
- respiratory: aerosol droplet, saliva
- enteric
- contact: mucosal, cutaneous
- percutaneous: blood-borne, arboviruses
- mother to child: congenital, perinatal
- zoonoses: ingestion, bites
