immune system Flashcards
whats the 2 main types of white blood cell
Phagocytes and Lymphocytes
movement of phagocytes
easily pass through blood vessel walls into surrounding tissue and move towards pathogens or toxins
what can phagocytes do after moving into a tissue / cell (2)
ingest and absorb the pathogens or toxins
release an enzyme to destroy them
what does phagocytes do after absorbing a pathogen
send out chemical messages that help nearby lymphocytes to identify the type of antibody needed to neutralise them
what do Pathogens have on their surface
have chemicals that are called antigens.
what does each lymphocyte carry?
specific type of antibody
what happens when lymphocyte with the appropriate antibody meets the antigen
lymphocyte reproduces quickly, and makes many copies of the antibody that neutralises the pathogen.
3 diff ways antibodys neutralise pathogens
- bind pathogens and damage or destroy them
- coat pathogens, clumping them together so that they are easily ingested by phagocytes
- bind to pathogen and release chemical signals to attract more phagocytes
how many natural barriers against pathogens do we have
6
what are the bodys natural barriers against pathogens
- skin
- blood clotting
- Inflammation to localise breaks in the barrier
- Phagocytosis to destroy invading microbes
- Ciliated mucous membranes that trap microbes in inhaled air
- Lysozyme in tears, saliva and stomach acid that kills bacteria.
why is the skin good as a natural barrier
complex organ has physical, chemical, and microbiological barriers to protect the host from external insults.
why is Blood clotting to seal wounds a good natural barrier
platelet plug is formed, and the external bleeding stops.
small molecules, called clotting factors, cause strands of blood-borne materials, called fibrin, to stick together and seal the inside of the wound
why is inflammation to localise breaks in the barrier good natural barrier
In response to injury and infection, specialised immune cells called mast cells release histamine.
Histamine causes blood vessels to widen (vasodilation).
This increases blood flow to the area.
increased blood flow leads to an accumulation of phagocytes and clotting elements at the site of infection.
where does histamine come from
mast cells
what do mast cells release
histamine
what do histamine cause
Histamine causes blood vessels to widen (vasodilation).
what does the vasodilation because of histamine do
increases blood flow to the area
why is phagocytosis a good natural barrier
cells can engulf pathogens or cells and internalise them
why are ciliated mucous membranes a good natural barrier
propel a liquid layer of mucus that covers the airways.
traps pathogens and other particles, preventing them from reaching the lungs.
what is found in tears, saliva and stomach acid
lysozomes
what do lyzozomes do
kill bacteria
what are lyzozomes
form of chemical defence against infection.
why does a specific immune response develope
as a result of antigens being recognised as foreign to the body
whats the 2 different immune responses
Humoral
Cell-Mediated
what is the humoral immunity response
antibody-mediated response
when does humoral immune response occur
when foreign material - antigens - are detected in the body. This foreign material typically includes extracellular invaders such as bacteria.
how is humoral immune response driven
by B cell lymphocytes
what do B cell lymphocytes produce
antibodies after the detection of a specific antigen
difference between humoral and cell-mediated response
cell-mediated immunity does not depend on antibodies.
how is cell-mediated immunity driven by
mature T cells, macrophages, and the release of cytokines in response to an antigen.
when does cell-mediated immunity happen
at body sites where cells are infected by a virus, bacteria, or fungi (intracellular invaders).
how can cell mediated immune cells identify recognize cancerous cells.
T cells
in what does humral response happen
blood plasma
how many steps for humeral response of immune system
5
humoral response accronym
bambi
BAMBI meaning
B lymphocytes have receptors specific antigen
Activation stimulates production of plasma cells, and memory cells
Memory cells still there incase
Binding of antibodies + antigen to form antibody/ antigen complex
Inactive which increases the rate of engulfment by phagocytes.
what happens if pathogen enters cell
can no longer be detected by the humoral immune response; instead, the cell-mediated immune response must take over to
what does cell-mediated response use
T cells to tag and destroy foreign antigens
where is T cells made
thymus
how are t cells activated
via interaction with an antigen presenting cell
what do t cells recognize
infected cells
how do t cells identify infected cells
with antigen present on their molecules
what are the 2 subtypes of t cells
cytotoxic T cell (TC)
Helper T cells (TH cells)
what does cytotoxic T cells do
it will clone itself, producing many TC cells with the correct receptors;
what do helper t cells do
releasing signalling molecules known as cytokines which can recruit natural killer cells and phagocytes to destroy infected cells and further activate TC cells
what is a cytotoxic T cell
subgroup of lymphocytes that are capable of inducing death to infected or tumour cells
whats cytokine
any of various small regulatory proteins that regulate the cells of the immune system
what is Cell-mediated immunity
involves cytotoxic T cells recognizing infected cells and bringing about their destruction
what are subgroups of lymphocytes
T and B cells
where are b cells made
bone marrow
where are t cells made
bone marrow but mature in the Thymus
what do the cytotoxic t cells split into
some active which destroy infected cells
inactive memory cells which make active Tc cells if infection returns
when does primary response happen
when you first get contact with a microbe/cancer/vaccine.
when does secondary response happen
the person is exposed to the same antigen
immune system can start making antibodies immediately
whats the role of the immune system
protects the body from pathogen and disease
what are some natural PHYSICAL barriers
skin
eyelashes
cilia
mucus
what are some CHEMCIAL natural barriers (3)
tears with lyzsomes
stomach acid
sweat (which is acidic)
2 differences between phagocytes and lymphocytes
lymphocytes have circular shape, phagocytes have a irregular shape
lymphocytes have large nucleus,
phagocytes have small irregular nucleus
lymphocyte shape
circular
phagocyte shape
irregular shape
lymphoctyes nucleus
large
phagocyte nucleus
small irregular
what do cytotoxic cells cause
lysis
pathogen defenition
organism capable of causing disease in its host
how many different groups of pathogens are there
6
whats the 6 different groups of pathogens
Viruses
Bacteria
Protozoan
Fungal
Worms
Prions
what is a virus
A biological agent that requires a host to reproduce.
how does virus work
take over the cell’s metabolism
viral genetic material gets into the host cell and is inserted into the host DNA to be replicated
how do virus replicate
virus then uses the host cell to make new viruses which then burst out
what does bacteria do
produce toxins that poison or damage the host cells in some way, causing disease
how does bacteria cause damage
damage the host cells by breaking down the cell membranes
some damage or inactivate enzymes.
what does fungi do
digest living cells and destroy them.
what causes symptoms of disease cause of fungi
Fungi digest living cells and destroy them combined with the response of the body to the damage
what are protozoans and what are they cause by
parasitic diseases caused by protozoa.
what are protoza
single-celled eukaryotes which feed on organic matter such as organic tissues.
how are protozans usually contracted
by either an insect vector or by contact with an infected substance or surface.
scary fact am protozea
Many of the most prevalent and deadly human diseases are caused by protozoa.
what are worms
These are large microparasites and can generally be seen with the naked eye.
wheres the 2 places worms live
intestinal worms that infect the gastrointestinal tract.
blood vessels. These are endoparasites.
where do the edoparasites live
in blood vessels
example of ectoparasites.
leeches
why are worms bad
receive nourishment and protection whilst disrupting their host’s ability to absorb nutrients.
how is athletes foot spread
direct physical contact
how is chicken pox spread
direct physical contact
how is tetanus spread
body fluids
how is aids spread
body fluids
mother to unborn baby
how can rubella spread
mother to unborn baby
how is common cold spread
airparticles
how is TB spread
airparticles
how is salmonella spread
food
how is cholera spread
water
how is malaria spread
vector (insects)
4 different types of non-infectious diseases
allergies
inherited diseases
cancer
autoimmune disease
what are Non-infectious diseases
Non-infectious diseases include all diseases that are not caused by pathogens
what are non-infectious diseases caused by
They are generally caused by a combination of genetic and environmental factors other than pathogens.
risks for non-infectious diseaseses
age
gender
inherited genes
environmental factors including exposures such as radon
behaviours such as smoking
what causes tuburculosis
disease caused by an infection with the bacteria Mycobacterium tuberculosis complex.
how is tb spread
Airborne droplets from person to person by coughing, sneezing or speaking
how is tb treated
Antibiotics, taken for 6 to 9 months.
symptoms of athletes foot
itching
burning
redness
stinging on the soles of the feet
skin may flake, peel, blister, or crack.
who can get athletes foot (risk factors i guess?)
anyone whose feet tend to be damp or sweaty can get this infection
fungi that cause athlete’s foot thrive in warm, moist environments.
where does athletes foot affect
affects the soles of the feet and the areas between the toes, and it may also spread to the toenails.
wheres more uncomon places athletes foot can spread to
palms of your hands, groin, or underarms if you touch your feet and then touch another area of your body.
chicken pox symptoms
Rash
Coughing
Sneezing
how is chicken pox spread
The virus is spread by contact between people
what is tetanus caused by
caused by a bacteria
where does bacteria that causes tetanus live
on dirty objects such as rusty nails
what needs to happen for you to get tetanus
an open cut that touches something with the bacteria on it the bacteria will pass through the cut into you body.
tetanus symptoms
Lockjaw
Spasms
how is aids treated
No treatment, only antiviral drugs that can slow down the progress of the virus.
AIDS symptoms
Fever
rash
cold-like symptoms
swollen glands that last for over three weeks.
how is AIDS spread
Contaminated blood, shared needles and body fluids during sexual intercourse.
what does AIDS do
destroys lymphocytes
weakens immune system,
people can get serious infections that they normally wouldn’t.
whats rubella
mild febrile viral illness.
rubella symptoms
mild cold
slight fever
sore throat
enlarged lymph glands in the neck and behind the ears, rash which lasts 3 days ish
where does rubella rash start
on face and works way down the body
how does rubella spread
- from a pregnant women to her unborn child through the placenta
- spread by airborne droplets (coughing and sneezing)
- direct contact
malaria symptoms
Headache
Vomiting
Diarrhoea
how is malaria spread by
mosquito
technically how is malaria spread
person with malaria bitten by a mosquito - takes up the micro-organism that causes malaria with the blood.
When the mosquito bites someone else the micro-organism is transferred and that person catches malaria.
common cold symptoms
Coughing
Sneezing
Sore throat
Headache/tummy ache
how is common cold spread
by sneezing
scientifically how does common cold spread
sneeze the virus, carried into the air in the mucus in the sneeze.
someone else breathes in the mucus when it is in the air they will become infected with the cold virus
how is food poisoning spread
by bacteria in food.
why does food poisoning happen
cooking kills bacteria
undercooked food
scientifically how is food poisoning spread
if your food is not cooked all the way through the bacteria are not killed. If the food is eaten the bacteria are able enter you body.
cholera symptoms
Vomiting
Diarrhoea
Muscle cramps
how does cholera bacteria leave the body
passes out in their urine.
how does cholera spread
someone drinks dirty water that contains the urine they will become infected with cholera
hiv prevention
condoms and disposable gloves if any danger of contact with contaminated blood.
cure for hiv?
no
what medication do they give you for HIV
Antiviral agents can be used, but they only prevent the multiplication of the virus inside cells and must be taken throughout life.
HIV symptoms
flu-like symptoms.
infection progresses (weaker immune system) risk of contracting other infections such as tb increases and other opportunistic bacteria
how is HIV spread
- unprotected sex
- contaminated blood transfusions
- from mother to child during pregnancy, delivery, or breastfeeding
- spread through bodily fluids such as blood, semen, pre-seminal fluid and breast milk
what body fluids do not spread HIV
saliva, sweat and tears, do not transmit the virus.-
AIDS full name
Acquired Immune Deficiency Syndrome
what does HIV affect
virus infects lymphocytes which are part of the body’s immune system. - weakens immune system
full name for chlamydia
chlamydia trachmatis
chlamydia trachmatis prevention
using condoms
not having sex
can chlamydia be cured
yes
how is chlamydia cured
cured by antibiotics
chlamydia symptoms
symptoms do appear several weeks after infection.
in women -
burning with urination.
in men -
discharge from the penis
burning with urination
pain and swelling of one or both testicles.
Both genders may find sexual intercourse painful.
longterm affect of chlamydia
it could cause infertility in adults.
what can chlamydia do to unborn baby
cause conjunctivitis in babies during the process of birth
spread to babys lungs.
diagnosis of chlamydia
screening
on the urine or a swab of the cervix, vagina, or urethra.
Rectal or mouth swabs are required to diagnose infections in those areas.
how is chlamydia spread
sexual intercourse
plasmodium symptoms
fever
tiredness
vomiting
headaches
seizures
yellow skin
coma
death
when do plasmodium infection symptoms start to show
10-15 days after being bitten by an infected mosquito
how is malaria treated
treated with antimalarial medications
plasmodium prevention
using mosquito nets and insect repellents
Anti-malarial tablets can be taken by travellers to prevent infection.
what does plasmodium cause
malaria
what is plasmodium
unicellular protozoan parasite
how is plasmodium spread
spread via female mosquitoes of the genus
bite humans and inject Plasmodium into the blood stream
mosquito bite introduces the parasites from the mosquito’s saliva into a person’s blood
what happens when plasmodium enters blood stream
parasites travel to the liver where they mature and reproduce
what type of disease is toxoplasma gondii
parasitic disease
how is toxoplasma gondii spread
- eating poorly cooked food that contains cysts,
- exposure to infected cat faeces,
- from an infected mother to her baby during pregnancy.
symptoms of toxoplasma gondii infection
usually no symptoms BUT sometimes
mild, flu-like illness such as muscle aches and tender lymph nodes.
In a small number of people, eye problems may develop
prevention for toxoplasma gondii infection
properly cooking food.
Pregnant women recommended not to clean cat litter boxes
treatment of toxoplasma gondii
Treatment of otherwise healthy people is usually not needed.
prevention of athletes foot
avoiding walking barefoot in public showers
keeping the toenails short
wearing big enough shoes
changing socks daily.
what to do if you have athletes foot
When infected, the feet should be kept dry and clean and wearing sandals may help.
treatment of athletes foot
antifungal medication
what is athletes foot fancy name
tinea pedis
tapeworm prevention
thoroughly cooking meat.
tapeworm treatment
treated with a medicine taken by mouth.
medications paralyse the tapeworms which let go of the intestine, dissolve, and pass from your body with bowel movements.
tapworm symptoms
nausea
weakness
diarrhea
loss of appetite
fatigue
weight loss
mineral/vitamin deficiencies
how many stages of lifecycle do tapworms have
3
whats the 3 stages of life for worms
immature stage called a larva
adult stage at which the worm can produce more eggs
what does CJD stand for
Creutzfeldt–Jakob disease
symptoms of CJD
memory problems
behavioural change
bad coordination
visual disturbances.
Later symptoms include dementia, involuntary movements, blindness, weakness, and coma
survival rate of CJD
About 70% of people die within a year of diagnosis.
is there a cure for CJD
no
treatment of CJD
palliative care
Psychiatric symptoms like anxiety & depression can be treated with sedatives & antidepressants.
how is CJD spread
transmitted by blood transfusion.
what are prions
misfolded prion proteins that build up in the brain and cause other prion proteins to misfold as well.
what do prions cause
This causes the brain cells to die, releasing more prions to infect other brain cells
CJD damage
clusters of brain cells are killed and deposits of prion protein called plaques appear in the brain. Prion infections also cause small holes to develop in the brain, so it becomes sponge-like. The damage to the brain causes the mental and physical impairment associated with CJD. Prions can survive in nerve tissue, such as the brain or spinal cord, for a very long time, even after death.
where does CJD affect
brain
what is CJD caused by
caused by a prion
why are prions absolute pricks
Prions aren’t destroyed by the extremes of heat and radiation used to kill bacteria and viruses, and antibiotics or antiviral medicines have no effect on them.
covid symptoms
fever
cough
fatigue
shortness of breath
loss of sense of smell
Complications may include pneumonia & acute respiratory distress syndrome.
how is covid spread
spread mainly through respiratory droplets produced when an infected person coughs, sneezes, or talks.
touching a contaminated surface or object, and then touching their own mouth, nose
direct contact
Airborne transmission
