inflammation Flashcards
what is inflammation
a reaction/response to injury or infection involving cells such as neutrophils and macrophages
when is inflammation good
infection
injury
inflammatory process fights off infection and repairs injuries
when is inflammation bad
autoimmunity
when it is an over reaction to the stimulus
how is inflammation good like what does it do
Destruction of invading microorganisms and the walling off of an abscess cavity thereby preventing the spread of infection
two types of inflammation
acute
chronic
describe acute inflammation
sudden onset
short duration
usually resolves
describe chronic inflammation
slow onset or sequel to acute
long duration
may never resolve
what cells are involved in inflammation (5)
neutrophil polymorphs
macrophages
lymphocytes
endothelial cells
fibroblasts
main cell in acute inflammation
neutrophils
main cell in chronic inflammation
macrophages and lymphocytes
what are neutrophils
mobile bags of enzymes with vesicles that contain enzymes to kill things
move around and latch onto things and then release enzymes
describe neutrophil polymorphs
short lived
first on the scene of acute inflammation
cytoplasmic granules full of enzymes that kill bacteria
usually die on the scene of inflammation
release chemicals that attract other inflammatory cells such as macrophages
describe macrophages
long lived cells (weeks to months)
phagocytic properties
ingest bacteria and debris
may carry debris away
may present antigen to lymphocytes
describe lymphocytes
long lived cells (years)
produce chemicals which attract in other inflammatory cells
immunological memory for past infections and antigens
describe endothelial cells
line capillary blood vessels in areas of inflammation
become sticky in areas of inflammation so inflammatory cells can stick to them
become porous to allow inflammatory cells to pass into tissues
grow into areas of damage to form new capillary vessels
describe fibroblasts
long lived cells
form collagen in areas of chronic inflammation and repair
describe acute appendicitis
unknown precipitating factor
neutrophils appear
blood vessels dilate
inflammation of serosal surface occurs
pain felt
appendix either surgically removed or inflammation resolves or appendix bursts with generalised peritonitis and possible death
example of acute inflammation
acute appendicitis
example of chronic inflammation
tuberculosis
describe tuberculosis
no initial acute inflammation
mycobacteria ingested by macrophages
macrophages often fail to kill the mycobacteria
lymphocytes appear
macrophages appear
fibrosis occurs
what are granulomas
a collection of macrophages tryna kill something but not very effectively
surrounded by lymphocytes
what does ice do to inflammation
causes sphincter muscles on capillaries to shut
reduces swelling and inflammation
what is granulation tissue
an important component of healing and comprises small blood vessels in a connective tissue matrix with myofibroblasts
what do u use antihistamine tablet or cream for
mosquito bites
what do granulomas look like
epithelioid macrophages (look like epithelial cells) – bundles of macrophages
how does antihistamine work
histamine is a chemical mediator of acute inflammation
how do ibuprofen or aspirin work
inhibit prostaglandin synthethase
prostaglandin is chemical mediator of inflammation
what do cortico steroids do
they are anti inflammatory
bind to DNA
example of steroid cream
betnovate
how to treat impetigo
antibiotics
examples of when inflammation is bad
An abscess in the brain would act as a space-occupying lesion compressing vital surrounding structures
Fibrosis resulting from chronic inflammation may distort the tissues and permanently alter their function
define acute inflammation
the initial and often transient series of tissue reactions to injury
4 steps of acute inflammation
- Initial reaction of tissue to injury
- Vascular component: dilation of vessels
- Exudative component: vascular leakage of protein-rich fluid
- Neutrophil polymorph (white blood cell) is the characteristic cell recruited to the
tissue
4 outcomes of acute inflammation
resolution
suppuration
organisation
progression to chronic inflammation
what does resolution mean
the complete restoration of the tissues to normal after an episode of acute inflammation
what does suppuration mean
pus formation eg abscess
what does organisation mean
- healing by fibrosis (scar formation)
- when there is substantial
damage to the connective tissue framework and/or the tissue lacks
the ability to regenerate specialised cells - dead tissues and acute inflammatory exudate are
fist removed from the damaged areas by macrophages - The defect then becomes filled by the ingrowth of a specialised
vascular connective tissue - granulation tissue
5.The granulation tissue then gradually produces collagen to form a fibrous (collagenous) scar constituting the process of repair
what is pus made of
a mixture of living, dying and dead neutrophils and bacteria, cellular debris and globules of lipid.
what 3 processes are involved in tbe response to acute inflammation
Changes in vessel calibre and flow
Increased vascular permeability and formation of the fluid exudate
Formation of the cellular exudate – emigration of the neutrophil polymorphs into the extravascular space
6 causes of acute inflammation
- Microbial infections e.g. viruses
- Hypersensitivity reactions e.g. parasites
- Physical agents e.g. trauma/ radiation
- Chemicals e.g. corrosives/ acids
- Bacterial toxins
- Tissue necrosis e.g. ischaemic infarction
define chronic inflammation
the subsequent and often prolonged tissue reactions following the initial response
4 causes of chronic inflammation
- Primary chronic inflammation
- Transplant rejection
- Progression from acute inflammation
- Recurrent episodes of acute inflammation
