Freshers Flu

Question 1

Action of Influenza

Answer 1

Haemagluttin receptors on surface of virus attach to silica acid on surface of cell membrane of respiratory endothelial cells
Endocytosis + release of RNA into host cytoplasm
RNA into host nucleus
Replicated using host cell machinery
Into cytoplasm again and uses ribosomal machinery to synthesise viral proteins
Viral RNA plus proteins reassemble influenza virus now gonna infect other cells

Question 2

Neuraminidase

Answer 2

Allows the virus to leave the cell by cleaving the silica acid side groups from glycoproteins - else the HA would remain bound to the sialic acid

Question 3

What type of enzyme is neuraminidase?

Answer 3

Glycoside hydrolase

Question 4

Antigenic drift

Answer 4

Natural mutation over a long period of time of a known strain resulting in small genetic changes - accumulation over time results with viruses having slightly different antigenic material so loss of immunity + mismatch in vaccination

Question 5

Antigenic shift

Answer 5

Abrupt major change in genetic material - phenotypic change which requires a new antigenic response ; only in Influenza A as other types are unable to infect other animals

Question 6

Mechanism of antigenic shift?

Answer 6

Two or more different strains of virus can combine ; pigs can be infected by both human and avian strains of Influenza A so act as a reservoir for genetic reassortment of Influenza A

Question 7

Cold vs flu timescale

Answer 7

Flu appears quickly within a few hours and cold appears gradually

Question 8

Flu vs cold systematic

Answer 8

Flu is systematic but cold affects mainly nose and throat

Question 9

Flu vs cold feeling?

Answer 9

Flu - too exhausted + unwell to carry on as normal ; cold allows you to still feel well enough to do activities

Question 10

Pressure in your ears and face

Answer 10

Cold

Question 11

Diarrhoea/difficulty sleeping/loss of appetite

Answer 11

Flu

Question 12

What is a collateral history?

Answer 12

Ask someone close to the patient (parent/carer) about the patient’s symptoms

Question 13

Differential diagnoses

Answer 13

List of possible conditions that share the symptoms presented

Question 14

Runny nose/regular sneezing

Answer 14

More leaning towards the cold

Question 15

The symptoms are…

Answer 15

The body’s response to the virus

Question 16

In a cold, the symptoms are

Answer 16

Largely contained within the upper respiratory tract

Question 17

Systemic

Answer 17

All over the body (flu) ; flu is more likely to release cytokines all around the body resulting in muscle pain/fatigue

Question 18

How does a runny nose originate?

Answer 18

Common in cold ; often due to leakage from vasodilation of vessels in the nasal area

Question 19

COVID is

Answer 19

More flu like than cold like

Question 20

Common cold viruses?

Answer 20

Rhinovirus (most common)
Adenoviruses
Coronaviruses
Influenza
Different subtypes of the last two exist that lead to differing outcomes

Question 21

Job of the spike protein?

Answer 21

Allow the virus to attach on to a host cell (epithelial cells in airways)

Question 22

If the spike proteins mutate?

Answer 22

They bind BETTER to the existing protein or bind to a different protein

Question 23

COVID mechanism

Answer 23

ACE2 is the cell receptor on the epithelial tract ; SARS-COV-2 binds to that - entry into epithelial cell - virus replicates and releases itself back into circulation

Question 24

ACE2 is also part of the

Answer 24

Renin angiotensin system

Question 25

What happens after entry of covid into epithelial cell

Answer 25

ACE2 is down regulated - now that epithelial cell has less protection against build up of some of these damaging chemicals ; leading to acute lung injury/vasoconstriction etc

Question 26

Influenza virus has two main proteins associated with it?

Answer 26

Haemagglutinin - looks like a rod (gets virus into cell) Neuraminidase - looks a lot more like a mushroom (allows virus to be released once it is replicated)

Question 27

Influenza virus initial binding

Answer 27

Haemagglutinin binds to sialic acid which is RIGHT at the tip of the carbohydrate chain of the glycoprotein embedded in the epithelial cell membrane Replicatesnow etc and produces a lot more copies of the influenza virus

Question 28

How is the influenza virus released back out of circulation?

Answer 28

The virus reattaches itself to sialic acid and neuraminidase is enzyme that cleaves sialic acid from sugar backbone

Question 29

Different strains with influenza

Answer 29

Is due to mutations in neuraminidase/haemagglutinin

Question 30

Rhinovirus attaches via

Answer 30

ICAM-1; proteins that hold together Rhinovirus kinda detach and disassemble

Question 31

Risk factors (especially during freshers)

Answer 31

Lack of sleep Alcohol consumption Close proximity ; different people Stress/poor diet

Question 32

Risk factors for general pop.

Answer 32

Chronic illnesses Ageing population Immune-comprimised Pregnant Obese/co-morbidities

Question 33

Sleep

Answer 33

Lymphocytes migrate to lump nodes during sleep ; immune surveillance - responding to any virus/bacteria circulating around

Question 34

Stress

Answer 34

High levels of stress hormone (cortisol + adrenaline) harms immune system

Question 35

Exercise

Answer 35

Moderate levels of exercise = good cortisol Excessive/none is bad for immune system - when extreme exercise not enough resources dealing with immune system and too much on exercise

Question 36

Triggers that may push to go to the doctor

Answer 36

Peer/family pressure Worsening of symptoms Confusion/recovering faster Interpersonal crisis Sanctioning (when pressured/advised essentially)

Question 37

Helman's folk model

Answer 37

Why does a patient see a doctor ; 6 questions they want to know What happened? Why? Why me? Why now? What should I do now? What would happen to me if I did nothing?

Question 38

Zolas triggers

Answer 38

Urge you to go see a doctor

Question 39

Influenza A has

Answer 39

HA NA Matrix 2

Question 40

Influenza B has

Answer 40

HA NA 2 other membrane proteins

Question 41

Matrix 2

Answer 41

Proton-selective ion channel protein integral to viral envelope of influenza A