Hypersensitivity And Host Defence

Question 1

Type 1 sensitivity mechanism

Answer 1

Ige mediated ( immunoglobulin ) antibodies that cause allergic reaction

Bind to basophils to secrete histamine

such as hay fever and anaphylaxis .

Question 2

type 2 sensitivity and mechanism

Answer 2

igm mediated ( polymer if ige)
cytotoxic response
tissue damage and altered receptors
igg binds to cell surface receptors

Question 3

type 3 lung sensitivity

Answer 3

igg mediated - set in after a few hours

hypersensitivity pneumonitis

Question 4

type 4 sensitivity

Answer 4

t cell mediated
granuloma formation
delayed response

Question 5

histamine and its effect on t1

Answer 5

histamine can have inflammatory and anti inflammatory response

vasodilation and bronchoconstriction

Question 6

Mechanism of anaphylaxis

Answer 6

First exposure , ige indirectly activates mast cells
Second exposure antigen binds to ige in blood , this complex then binds to high affinity ige receptor
Mast cell degranulates , inflammatory mediators released via exocytosis

Question 7

Systemic effects of anaphylaxis

Answer 7

Increased vascular permeability
Decreased vascular tone
Bronchoconstriction

Question 8

define intrinsic defence

Answer 8

non-immune mechanism of precenting infection

E.g: cough, sneezing, muco-ciliary clearance

Question 9

define Innate / cell mediated immunity

Answer 9

Non-specific immune response present from birth

No memory

Question 10

what do b cells form in the immune response

Answer 10

Specific to the antigen
Factories for antibodies
Activate other T-cells
Create memory cells

Question 11

non immune barriers

Answer 11

resp epithelium - cilia can trap particulates , barrier
mucus - lubrication and protection , mucocilliary escalator
coughing inspire, close epiglottis

Question 12

neutrophil response

Answer 12

identify threat
activation
adhesion
migration
phagocytosis
bacterial killing 
apoptosis

Question 13

Immune mechanisms specific to the lungs

Answer 13

Coughing and sneezing
Alveolar macrophages
Muco ciliary escalator

Question 14

What is an antigen presenting cell

Answer 14

A macrophage that phagocytosed a pathogen

Question 15

what happens to the lungs as we age

Answer 15

decreased compliance and elasticity
increase in vq mismatch
slower immune responses

Question 16

what is mucus made of

Answer 16

water, 
epithelial (surface) cells
dead leukocytes
mucin, 
and inorganic salt