Influenza (Flu)

Influenza or the flu is a contagious

viral infection that attacks your nose

throat

and lungs

it can cause fever

chills runny nose sore throat

cough muscle aches and fatigue the flu

virus is extremely small and only

visible through electron microscopes

inside the virus genetic material

contains the information to make more

copies of the same virus a protein shell

provides a hard protective enclosure for

the genetic material as the virus

travels between the people or animals it

infects an outer envelope allows the

virus to infect cells by merging with

the cell's outer membrane projecting

from the envelope are spikes of protein

molecules the flu virus uses its h

spikes like a key to get inside your

cells n spikes allow copies of the virus

to break away from your infected cells

to infect more cells there are 17 known

types of H spikes and nine types of n

spikes that scientists use to name

different flu viruses such as the virus

h5n1 you get the flu by touching an

object that has the flu virus on it or

through exposure to body fluids from

people or animals infected with the

virus when an infected person talks

coughs or sneezes droplets carrying the

influenza virus may land in your mouth

or nose and then move into your lungs

once inside your body

the influenza virus comes into contact

with cells in your nose throat or lungs

the H spike on the virus insert into a

receptor molecule on your healthy cell

membrane like a key in a lock

this action allows the virus to get

inside your cell

next the virus travels inside a sack

made from your cell membrane to your

cells nucleus

then the viral envelope and cell

membrane sack combined allowing the

viral genetic material to leave the sack

and enter the nucleus

the viral genetic material hijacks the

energy and materials in your cell's

nucleus to make thousands of copies of

itself some of the genetic material

moves out of the nucleus then attaches

to ribosomes which are the protein

building parts of your cell ribosomes

use information from the genetic

material to make other viral proteins

such as the h and n spikes a packaging

structure in your cell called the Golgi

apparatus carries the h and n spikes in

vesicles which merge with your cell's

membrane all the parts needed to create

a new virus gather just beneath your

cell's membrane

then a new virus begins to butt off from

the cell's membrane during this process

the newly created virus gets stuck on

your cell's membrane when a viral h

spike locks on to membrane receptors

however the virus has a way to get

around this problem

the viral end spike frees the virus by

cutting it away from the receptor new

influenza viruses are now free to infect

more of your cells and cause you to

develop the flu

if you have the flu your doctor may

prescribe oseltamivir which you would

take orally or zanamivir which you would

take using an inhaler to help speed your

recovery or reduce your risk for

complications

these antiviral drugs stop the influenza

virus by blocking the viral and spike

from freeing the virus

this causes the new viruses to stick to

the surface of your cell so they cannot

escape and infect more of your cells

the best way to protect yourself from

the flu is to get the flu vaccine every

year you may receive the vaccine as a

shot which contains dead versions of

several types of the virus or you may

receive it as a nasal spray which

contains several types of live but very

weak forms of the virus the vaccine

exposes your body to several types of

the influenza virus that are too weak to

cause infection but just strong enough

to stimulate an immune response within

two weeks cells in your immune system

make markers called antibodies which are

specific for only the types of flu you

were exposed to the antibodies attach to

each flu virus and prevent it from

attaching to your cells antibodies are

also able to attach to more than one flu

virus which causes viruses to clump

together your immune system responds to

signals from the antibodies by engulfing

and destroying the clumps of viruses

later if you are exposed to these types

of flu again your body recognizes and

destroys them so you will not develop

the flu from these same viruses for

continued protection against new flu

viruses you will need to get a flu

vaccine every year