wk 10- immunological Flashcards
immune system functions
recognises and destroys
- non self cells/ molecules
- abnormal cells that may have originated as self
first line defense: skin, mucosa of GIT, cornea, respiratory system etc (protective barrier)
second line defense: immune response
innate and adaptive
antigen
anything that triggers an immune response
immune system components
cellular
- Polymorphonuclear
-Phagocytic cells
-Natural killer cells
-antigen presenting cells
-mast cells
-basophils
-eosiophils
non cellular
-antibodies
-complement C
-acute phase proteins
-interferons
what do PMN cells do (neutrophils, eosinophils, basophils)
phagocytic - destroy microbes
short lived cells seen in acute inflammation
what do phagocyctic cells do
-macrophages, neutrophils
engulf microbes
antigen presenting
long lived cells in chronic inflammation
what is phagocytosis
engulfing antigen by
1. recognition of non specific part of antigen surface
2. recognition of antibody/complement bound to antigen (acquired immunity)
opsonisation
opsonins are molecule that allow phagocytosis to occur by coating antigens for destruction (C and antibodies)
natural killer cells
target virus infected cells/tumour cells
release interferon which protects non infected cells
antigen presenting cells
dendritic cells
connect innate immunity (non specific) with adaptive immunity (acquired) by presenting fragment of ingested antigen on surface to T cells
mast cells and basophils
trigger cytokines and inflammatory mediators and cause type 1 hypersensitivity reactions that occur with atopic allergy
eosinophils
phagocytose and granulocytes
acquired immunity (specific)
requires prior exposure to antigen
has memory and specificity to allergen
facilitated by 2 types of leucocytes
B lymphocytes (humoral immunity) and T lymphocytes (cell mediated immunity)
humoral immunity
B cells bind with antigen, activated by a helper T cell, produces and plasma and memory cell to which the plasma cell produces an antibody for antigen.
if the same antigen invades, the memory cell helps activate faster removal
cell mediated immunity
T cells dont produce antibody like B cells do but they recognise antigens by a surface receptors
HIV/AIDS
secondary immunodeficiency disorder
HIV targets T cells which leads to AIDs (diagnosed when: T cell count below 200 or 1 or more opportunisitic infections or cancer)
transmission:
unprotexted sex
blood fusions/needles
mother to child/breastfeeding
treatment of AIDs
antiretroviral therapy
-doesnt cure but manages T cell count and immune function
it is possible for people with HIV to live a normal lifespan ( not immunodeficiency until its AIDS)
primary/secondary immunodeifficency disorders
body fails to adequately provide immune response
seoondary
causes:
1. systemic disorders (diabetes, HIv)
2. immunosuppresive treatments (radiation, corticosteroids)
3. severe illness (infections/burns)
4. chronic illness
if you think youve been exposed to HIV
get tested 6, 12 weeks and 6 months after exposure
get a blood count and renal/hepatic function tests 2 weeks after
and post exposure prophylaxis
autoimmune disorders
body incorrectly recognises own tissues as antigen and attacks self
rheumatoid athritis
hashimotos thyroiditis disease
graves disease
Systemic Lupus Erythamtous
Psoriasis
Guillian-Barre syndrome
hypersensitivity disorders
immune system provides an over response or inappropriate response to antigen
4 types
type 1- IgE (immediate)
type 2- antibody-coated
type 3- immune complex
type 4- T cell mediated (delayed)
type 1 hypersensitivity disorders
urticaria- hives
atopic diseases:
asthma
atopic dermatitis
systemic anaphylaxis
allergic rhinitis
conjunctivits
type 2 hypersensivitiy disorders
results when antibody binds to self structures
examples:
coomb’s positive haemolytic anaemias
hashiomotos thyroiditis
type 3 hypersensitivity disorders
immune complex mediated
examples
RA
serum sickness
acute glomerulonephritis
type 4 hypersensitvity disorders
t cell mediated -delayed
contact dermatitis
drug/ hypersensitivty/allergy
when to refer
anaphylaxis
hayfever
allergic rhinoconjunctivits
common causes
dust mite
pollens
animals
food allergy treatment
epipen
avoidance
not an intolerance, it results in hives, swelling and anaphylaxis
anaphylaxis
SEVERE life threatening type 1 hypersensitivity
symptoms
hives
itching
swelling
wheezing
shortness of breath
nausea
vomiting
cramping
redness
