Please enable JavaScript.
Coggle requires JavaScript to display documents.
Diseases & Immunity (Unit 10) - Coggle Diagram
Diseases & Immunity (Unit 10)
TERMs:
Pathogen: disease-causing organisms
Transmissible diseases: pathogen can be passed from one host to another
Endemic: a disease that exist permanently in particular region / population
Epidemic: an outbreak of disease that attacks many people about the same time & may spread through one/ several communities
Pandemic: when an epidemic spreads throughout the world
Incubation period: period of time between original infection & appearance of 1st symptoms
carrier: a person who infected but show no symptoms
vector: an organism which carries a disease from human to human
direct transmission: spread of disease through physical contact, bodily fluid, blood, etc.
through contaminated objects, food, airborne transmission etc.
Method Of Transmission
Indirect contact:
through air
touching contaminated food and surfaces/objects
in food & drink
insect vectors
Direct contact:
in blood, e.g. from scratch
sexual activity
Body defences to pathogens
First Line
Mechanical barriers:
the dead outer layers of the skin form a barrier to entry
the hairs in the nose trap larger particles that you breathe in.
Chemical barriers:
stomach makes hydrochloric acid that kills pathogens in food
cells that line the airways (trachea & bronchi) make mucus that traps small dust & microorganism
Second Line
White blood cells in blood:
phagocytes - engulf bacteria/ viruses by phagocytosis
lymphocytes - produces antibodies
Types
of phagocytes & lymphocytes:
Phagocytes
Neutrophils (three-lobed nucleus)
Macrophage [monocytes] (kidney-shaped nucleus)
Eosinophils - bi-lobed nucleus (two)
Basophils - bi-lobed nucleus (two)
2.Lymphocytes
T-cell
B-cell
Types
of Leukocytes (WBC):
Granulated (contains digestive enzymes)
neutrophils
macrophage
Agranulocytes (do not have small particles on cytoplasm)
monocytes
lymphocytes
Antibodies
Antibodies are produced by
lymphocytes
--> formed in
lymph nodes
Lymphocytes produced antibodies in response to presence of pathogens such as
bacteria
This is because alien cells have chemicals called
antigens
on surface therefore different antibody is produced for each antigen
(cont.)
(cont.)
Antibodies make bacteria clump together in preparation for action: phagocytes / neutralise toxins produced by bacteria
Once antibodies have been made, they remain in blood to provide long-term protection (memory cells)
some lymphocytes memorise antigens the body has been exposed to
they can rapidly reproduce & produce antibodies to respond to further infection by the same pathogen (disease-causing organism)
THIS IS
active immunity
- defence against pathogen by antibody production in body; after infection / vaccination
How antibodies work:
slides 16
Autoimmune disease:
sometime the immune system does not work perfectly so when this happens it detect our won antigen as something foreign
where out immune system destroy healthy tissue by accident
Can cause variety of disease:
rheumatoid arthritis
multiple sclerosis
type 1 diabetes
Types of diabetes:
Type 1 diabetes - autoimmune reaction attacks cells that produce insulin (pancreas)
Type 2 diabetes - insulin deficiency / resistance
Gestational diabetes - high blood glucose during pregnancy
Insulin is a
hormone
that:
regulates the concentration of glucose in blood
stimulates liver & muscle to store glucose as glycogen
Symptoms of type 1 diabetes:
weight loss : cells use protein & fat instead of glucose as sources of energy
thirst : due to increase concentration of glucose in blood, it lowers water potential
tiredness : lack of glycogen that can be converted to glucose for energy especially in between meals
Vaccination:
to promote active immunity
vaccine contains:
live pathogens (weakened)
dead pathogen
antigens taken from surface of pathogens
it is a artificial way to gain immunity
Passive immunity:
when immunity is required in a hurry antibodies may be given via injection
antibodies can be taken from another individual
temporary but instance (example) immunity so memory cells will not be produced
example:
mother to infant through breastfeeding
antivenom injection when bitten by venomous animals (snake etc)
Preventing infection:
Personal hygiene:
wash hand after going to toilet
wash hair with shampoo to prevent dandruff/ lice
dental hygiene
wash themselves (esp. in hot weather)
cuts & wounds should be cleaned with antiseptic & plaster
Hygienic food preparation:
food should be covered to keep flies away
kitchen surface should be cleaned with disinfectants
food should be cooked throughly
water for cooking/ drinking should be sterilized or boiled if it comes from source that might contaminated
Proper waste disposal
household waste should be put into covered binds and collected regularly
garbage collected should be recycled, incinerated, buried properly in landfill sites
Sewage treatment
toilet waste should be disposed properly through drainage pipes to a sewage treatment works.