UNIT 12-DISEASES AND INFECTION
Learning aim A: Investigate different types of diseases and infections that can
affect humans
A pathogen is a microorganism that causes disease via entering the human body. When
pathogens enter the human body, it can be reproduced or if pathogens are on a surface
area and a person touches it, the pathogen will replicate as they touched the surface area.
Pathogens can be spread through cough, sneeze or skin contact. There are different ways in
which a person can protect against pathogens such as washing hands, vaccinations or do not
share personal items. These pathogens can be communicable or non-communicable
diseases. There are five types of pathogens which are bacteria, viruses, protist, fungi and
parasite worms.
Communicable diseases are illnesses that can be spread or transferred from one person to
another. It can be spread by breathing the same air, direct contact, bitten by an insect.
Examples are influenza, measles and salmonella.
Non-communicable diseases are illnesses that are not transferred between people or other
organisms. It is also known as chronic diseases, the diseases are longer term and it is due to
genetic, environmental, psychological and behavioural factors. Examples are cancer,
diabetes, heart disease, neurological disorders.
GENETIC
Genetic disorders happen when there is a mutation or change in our genes.
Genetic disorders are classified into three categories: single gene,
chromosomal and complex disorders. It occurs when a part of chromosome is
missing, when genes shift from one chromosome to another or when there is
an extra or missing shifting.
Cystic fibrosis can be inherited from our parents where the lungs and digestive system are
clogged with thick and sticky mucus. This causes breathing and digestive problems. Also,
throughout the years cystic fibrosis can continue to damage the lungs causing to eventually
stop working. Some symptoms of cystic fibrosis are chest infections, coughing, shortness of
breathing, low weight, yellow skin and constipation. Cystic fibrosis can affect the liver
affecting the normal secretion and bile function produced in the liver. The bile can become
sticky, irritation and inflammation. In the lungs the mucus clogs the airways trapping germs
which can lead to an infection so people with cystic fibrosis need to avoid germs. Cystic
fibrosis with the mucus it blocks the pancreas as a result enzyme build up in the pancreas
instead of reaching the digestive system.
Down syndrome also known as ‘Trisomy 21’is a genetic condition where a child has
inherited an extra chromosome normally 46 chromosomes. The extra chromosome affects
the baby body and brain development which can cause mental and physical challenges for
the baby. Some physical features of down syndrome are flattened face, short neck, small
ears, short height, small hands and eyes, tiny white spots on the iris. Another factor that
, increases the chance of having a baby down syndrome is the mother’s age usually over 35
or above. There are three types of down syndrome such as trisomy 21 where about 95%
people have 3 separate copies of chromosome 21 instead of 2. About 3% has translocation
down syndrome which is another type of down syndrome this is when an extra or a whole
chromosome 21 is present but it is attached to a different chromosome rather than being
separate chromosome 21. Mosaic down syndrome is another type of chromosome which
2% people are affected from it. Some children have 3 copies of chromosome 21in their cells.
Down syndrome children can have delayed speech and language, behavioural issues such as
attention problems .There is no specific prevention for down syndrome however, if a
mother already has a child with down syndrome then before getting pregnant again she
should get a genetic counsellor to understand the possibility of having a child with down
syndrome . Another way is screening tests which includes taking the mother blood to test
some substance in the blood. Also, an ultrasound can be done as the doctor can look at the
baby’s fluid behind it back.
DIETARY
Dietary means eating a healthy and balanced diet in order to stay healthy. It is necessary to
consume food and drinks in the proper proportions and quantities. A healthy diet includes
fruits and vegetables, vitamins and minerals, protein and fibre, less than 30% fat, limited
salt, and less than 10% sugar .
Cardiovascular disease is a type of heart disease that causes blood vessels to become
clogged. This can result in a heart attack or a stroke. It can harm the heart muscle, valves,
and cause irregular heartbeats. A healthy lifestyle and diet reduce the risk factor or
increased chances of developing heart disease. Consuming a lot of foods high in saturated
fat, for example, can contribute to the development of heart disease. Eating a lot of fibre,
drinking a lot of alcohol, and eating a lot of sugar can all increase your chances of getting
heart disease. Obesity, hypertension, high cholesterol, and diabetes are other factors that
increase an individual's chances of developing a cardiovascular disease if they do not engage
in enough physical activity. Tobacco use via cigarettes is another risk factor .
Diabetes is a disease which occurs when a person blood glucose is too high. There are two
type of diabetes type 1 and type 2. Type 1 diabetes is when your body does not produce
enough insulin which controls blood glucose which is normally controlled by insulin
injections. It affects the body as without insulin blood glucose cannot enter cells and it will
build up in the bloodstream . Whereas type 2 diabetes is when the body does not respond
to insulin anymore. It can the body by a person being constantly thirsty, tiredness or the
need to pee. Furthermore, it can also affect a person normal life as they will have to change
their diet by having more carbohydrates, exercise more, take medicines or having regular
check-up .
DEGENERATIVE
Degenerative disease affects the tissues or organs of the body over time. It has an impact on
body activities such as movement, balance, breathing, talking, and heart function. Some
degenerative diseases are genetic while others are caused by medical conditions such as
alcoholism, tumours, and strokes. It can also be caused by chemicals, toxins, or viruses in
