Pat Flashcards
what are 5 cardinal signs of infection
-rubor (redness)
-dolor (pain)
-calor (heat)
-tumor (swelling)
-loss of function
3 stages of inflammation
- bradykinin + prostacyclin + NO mediate vasodilation
2.fluid exudate- vessel becomes leaky and fluid forced out
3.cellular exudate- neutrophils become abundant in exudate - chemotaxis, more neutrophils move to inflammation site due to chemicals released
neutrophils in acute inflammation
-migrate to edge of BV
-adhesion together
-
what is the sequence of acute inflammation
-injury/infection
-neutrophils phagocytose and release enzymes
-macrophages phagocytose
-either, resolution OR progression to chronic inflammation
what are the 4 outcomes of acute inflammation
-resolution, normal
-suppuration, pus formation
-organisation, tissue replaced with granulation tissue in healing process
-progression to chronic inflammation
what are neutrophil polymorphs
-WBCs
-contain lysosomes for phagocytosis
-1st cells at site of inflammation
-lifespan= 2-3 days
what are macrophages
-phagocytose debris/bacteria
-transport material 2 lymph nodes + present it to lymphocytes 2 induce secondary immune response
-lifespan= months-years
what is the sequence of chronic inflammation
-no/very few neutrophils
-macrophages + lymphocytes
-fibroblasts arrive
-often ends w. repair + scar tissue
what are lymphocytes
-lifespan= years
- produce antibodies, B lymphocyte plasma cells
-immunological memory cells
-secondary defence mechanism
what are fibroblasts
produce collagenous connective tissue in scarring following some types of inflammation
what are granulomas
-particular type of chronic inflammation
-collections of macrophages/histiocytes surrounded by lymphocytes
-may be due to TB or leprosy
-may be seen around foreign material in tissue
2 reasons why blood clots don’t form all the time
- laminar flow
- non sticky endothelial cells
what is thrombosis
formation of a solid mass of blood from constituents in an intact vessel in a living person
what is the 1st stage of thrombosis
platelet aggregation, clotting cascade, + feedback loop causes formation of fibrin mesh which traps RBCs
3 factors that can cause thrombosis
- endothelial cell injury (changes vessel wall)
- change in blood flow
- change in blood constituents
thrombosis risk factors
-smoking, harmful chemicals
-diabetes
-hypertension
-lack of activity
-high cholesterol
what is an embolism
solid mass of blood is carried thru circulation until it becomes stuck + blocks a vessel
causes of an embolism
usually a thrombus
otherwise air, cholesterol crystals, amniotic fluid, fat
what is ischaemia
reduction of blood flow , therefore O2, to a tissue
what is an infarction
tissue necrosis due to inadequate blood flow to affected area
which organs are less susceptible to an infarction
dual arterial supply in:
liver, lung and brain
what is resolution
initiating factor removed
tissue undamaged/able to regenerate
what is repair
initiating factor still present
tissue damaged + unable to regenerate
- damaged tissue replaced by fibrous tissue
-collagen produced by fibroblasts
look up in notes regeneration
and repair
what is atherosclerosis
accumulation of fibrolipid plaques in systemic arteries
-reduces blood flow
risk factors for atherosclerosis
-hypertension
-hyperlipidaemia
-cigarette smoking
-poorly controlled diabetes
process of atherosclerosis
-endothelium damaged
-ulceration of endothelium leads to development of atherosclerosis plaques
what can atherosclerosis cause
if plaque completely blocks artery- no blood flow to organ= infarction
what happens when pieces of plaque break off
pieces can travel downstream + block smaller vessels causing embolism/small infarcts
what is apoptosis
programmed cell death
- prevents cells with genetic damage continuing to divide
which protein detects DNA damage within cells
p53
how does a cell apoptose
series of proteins, trigger a release of activated enzymes, auto digest cell
2 examples of apoptosis for healthy functioning
development, eg webs between fingers
cell turnover, old cells replaced
2 examples of apoptosis in disease
-mutations in p53 gene
p53 no longer detects DNA damage, no apoptosis of damaged cells
-HIV virus induces apoptosis in CD4 helper cells = immunodeficient state
what is necrosis
destruction of large numbers of cells via an external factor
examples of necrosis
-infarction
-frostbite
-toxic venom
-pancreatitis
what does congenital mean
disease is present at birth
what is acquired disease
caused by non-genetic environmental factors