A1 the immune system

Question 1

pathogen size smallest to largest

Answer 1

viruses (nanometres)
bacteria (1-10um micrometers)
fungi (5-100 micrometers)
protozoa (5-100 micrometres)
worms (several mm-cm)

Question 2

phagocytes

Answer 2

2-8% wbc
monocytes
macrophages
dendritic calls (DC)
eat things

Question 3

granulocytes

Answer 3

eosinophils 1-4% wbc
neutrophils 40-60% wbc
basophils & mast cells 0.5-1% wbc
release toxic compounds

Question 4

natural killer cells (NK cells)

Answer 4

2-3% wbc
type of lymphocyte
kill virally infected cells and tumour cells

Question 5

lymphocytes

Answer 5

20-40% wbc

Question 6

T cells

Answer 6

CD8+ cytolytic t cells 20%
-kill virally infected cells, tumor cells and allografts
CD4+ helper t cells 45%
-Th1,Th2, Th9, Th17, regulatory t cells (Treg)
-help other cells by releasing cytokines
-regulate immune responses
Gamma delta T cells 5%
-immunoregulatory and cytotoxic

Question 7

B cells

Answer 7

23%
make antibodies

Question 8

3 main pathways

Answer 8

classical
lectin
alternative

Question 9

what do the pathways result in (complement)

Answer 9

phagocytosis
-by opsonising antigens
inflammation
-by attracting macrophages and neutrophils
membrane attack
-by rupturing cell wall of bacteria to lyse cells

Question 10

cytokines

Answer 10

small (5-20 kDa) secreted proteins
chemokins, interferons, interleukins, lymphokines, tumor necrosis facts
act through cell surface receptors
imp in host immune responses to ifection, inflammation, trauma, sepsis, cancer, and reproduction

Question 11

antibodies

Answer 11

aka immunoglobulin (ig)
Y shaped, produced by plasma B cells
recognise pathogen epitopes
main functions
-neutralisation
-agglutination
-complement
5 classes (isotopes)
-IgA, IgD, IgE, IgG, IgM

Question 12

innate v adaptive

Answer 12

innate
-inherent recogniton
-productive response
adaptive
-random recognition
-production response

Question 13

what does adaptive system recognise

Answer 13

antigen
-mol recognised by specific lymphocyte (or antibody)
-not recognised by innate (only t or b cell)
epitope
-exact site on antigen that is recognised and bound by antibody or t cell

Question 14

immunodeficiency
(hyporeactivity)

Answer 14

-neutrophil disorders
-antibody deficiency
-complement deficiency
-t-cell dysfunction

Question 15

immunopathology
(hyperreactivity)

Answer 15

-systemic autoimmunity
-organ-specific autoimmunity
-allergies and asthma
-pathogen induced pathology