IIH L11, L16-L18 Anatomy of the immune system and Viral block

Question 1

Why is lymph from the small intestine milky? A01

Answer 1

It contains chylomicrons and is therefore termed chyle

Question 2

What are lymph nodes? A01

Answer 2

Endothelium-lined sinusoids with macrophages that phagocytose and present to lymphocytes

Question 3

What is the rough size of a lymph node? A01

Answer 3

0.1 - 2.5cm

Question 4

What does the superficial lymph drain in parallel with? A01

Answer 4

Veins

Question 5

What does the deep lymph drain in parallel with? A01

Answer 5

Arteries

Question 6

How long is the thoracic duct? A01

Answer 6

38 - 45cm

Question 7

Where does the thoracic duct extend from? A01

Answer 7

L2 to level of clavicle

Question 8

Which side of the body does the thoracic duct collect from? A01

Answer 8

Left

Question 9

What does the thoracic duct travel between as it travels superiorly from L2? A01

Answer 9

Through the diaphragm posterior to the right crus
Between the abdominal aorta and IVC in the abdomen
Between the thoracic aorta and azygos vein in the thorax

Question 10

How is the viral genome protected? L16

Answer 10

By a capsid

Question 11

What is used to classify viruses? L16

Answer 11

RNA or DNA?
Double or single stranded?
Positive or negative sense?
Uses reverse transcriptase?

Question 12

Example of a cytophatic virus that totally destroys target cells by lysis and produces extremely high amounts of virus? L16

Answer 12

Polio

Adenovirus

Question 13

Example of a less pathogenic virus, chronic infection with small number of virus particles? L16

Answer 13

Flu

HIV

Question 14

Function of interferon stimulated genes? L16

Answer 14

Encode anti-viral proteins

Question 15

Function of IFNγ? L16

Answer 15

Macrophage activator

Question 16

As viruses are intracellular pathogens, on which type of MHC will they present? L16

Answer 16

MHC II

Question 17

Which MHC class used TAP protein? L16

Answer 17

MHC I

Question 18

What are prodromal symptoms? L17

Answer 18

The first symptoms of an infection

Question 19

Why are the prodromal symptoms of many viruses very similar? L17

Answer 19

Common cascade of interferon induced responses

Question 20

Which cell of the immune system is cytotoxic against virally infected cells? L17

Answer 20

NK cells

Question 21

What inhibits NK cells? L17

Answer 21

MHC presentation

Question 22

What are the three things that happen with an NK cell is activated? L17

Answer 22

IFNγ release
Granule release
Cytolysis of target cell

Question 23

What are the three cytotoxic pathways against virally infected cells? L17

Answer 23

NK cell activation
CD8+ cell activation
Antibody production

Question 24

What is the receptor on NK cells that binds to Fc portion of IgG? L17

Answer 24

FcγRIII

Question 25

Example of a zoonose virus? L18

Answer 25

Ebola

Question 26

What type of virus is influenza? L18

Answer 26

Segmented RNA virus

Question 27

What part of the body does influenza infect? L18

Answer 27

Upper and lower respiratory tract

Question 28

As influenza is an RNA virus, is it rapidly or slowly mutating in the population? L18

Answer 28

Rapidly

Question 29

Explain antigenic drift. L18

Answer 29

High mutation rate of an RNA virus means a likelihood of adaptive changes in the dominant membrane antigens e.g. seasonal flu epidemics

Question 30

What are the dominant membrane antigens found on an RNA virus? L18

Answer 30

Haemogglutinin | Neuraminidase

Question 31

Explain antigenic shift. L18

Answer 31

Re-assortment of individual segments of a segmented genome virus occurs if there is co-infection across species, and this can lead to a totally new strain causing a pandemic e.g. H1N1 Mexican Swine Flu 2009

Question 32

Two types of HIV? L18

Answer 32

HIV-1 and HIV-2 | HIV-2 is much slower progressing and often does not require treatment

Question 33

What type of virus is HIV? L18

Answer 33

Enveloped, single-stranded, positive sense, RNA virus with an integrated DNA provirus

Question 34

What protein does HIV bind to on CD4+ cells? L18

Answer 34

gp120 protein

Question 35

Which enzyme converts ss-RNA to the ds-DNA provirus? L18

Answer 35

Reverse transcriptase

Question 36

Function of integrase? L18

Answer 36

Cuts the host DNA and ligates in the provirus

Question 37

Examples of anti-viral? L18

Answer 37

Integrase inhibitor | Reverse transcriptase inhibitor

Question 38

What is HAART? L18

Answer 38

Highly active anti-retroviral therapy; combination of anti-virals

Question 39

First phase of HIV infection? L18

Answer 39

Acute seroconversion; fever, flu, diarrhoea, extremely high levels of virus, loss of CD4+ cells

Question 40

Second phase of HIV infection? L18

Answer 40

Asymptomatic infection; 7-15 years, no ill health but decreasing CD4+ cells

Question 41

Third phase of HIV infection? L18

Answer 41

AIDS; immuno-deficient, CD4+ cells below a critical point, suffers from a complex spectrum of potentially fatal infections

Question 42

How many members of the herpesvirus family are there?L18

Answer 42

Eight

Question 43

Which is the only vaccine for a herpesvirus family member? L18

Answer 43

Varicella Zoster Virus (VZV) for chicken pox/shingles

Question 44

What infection does HHV4 cause? L18

Answer 44

Ebstein-Barr Virus (EBV)

Question 45

What infection does HHV5 cause? L18

Answer 45

Cytomegalovirus (CMV)

Question 46

Example of a cancer-causing viral infection? L18

Answer 46

EBV as it can cause mild B cell lymphomas