Download F 7 Biology Assignment Topic: Non

F 7 Biology Assignment
Topic: Non - infection
Diseases
By Annie Ng
What is mean by non-infectious diseases?
1. Non infectious diseases are not caused by pathogen.
2. They are mostly associated with malnutrition,inappropriate
lifestyle or defected genes
Example:
a. Cancers
b. Cardiovascular diseases
c. Diabetes mellitus
Cancer
If body’s immune mechanisms are enable destroy the
abnormal cells which transform from normal cells to cancer cell
in response to virus ,hormones and some environmental factors,
cancer would develop.
Tumours
In our body,cells are constantly becoming old and dying, and
new cells are produced to replace them. Normally, the division and
growth of cells is orderly and controlled but if this process gets out
of control for some reason, the cells will continue to divide and
develop into a lump which is called a tumour.
Kinds of tumours
1. Benign tumour
2. Malignant tumour
Benign Tumour
1. They are rarely life-threatening.
2. They are surrounding by a covering or capsule.
3. They do not spread and invade the surrounding tissue.
4. They can growth to such a size as to cause compression to
and displacement of surrounding tissue or organ.
Malignant Tumour
1.Malignant tumours are life threatening
2.It invade and destroy nearby cells and tissue.
3.They may break off and spread through the blood vessels and
lymphatic drainage system to other parts of the body to form
new tumours.(metastasis)
4.Cancer is the name given to a malignant tumour
Schematic diagram of benign and malignant tumours
Possible causes of cancers
The factors that contribute to the development
of cancer are :
1. Exposure to carcinogens
-Physical agents
-chemical agents
-Biological agents
2.Hereditary predisposition
3.Lifestyle
Carcinogens
Carcinogens are agents that can cause cancer or increase
the risk of cancer.
Physical agent:
- These including X-ray ,cosmic ray radiations
emitted from radon,ultraviolet radiation etc
- X-ray ,cosmic ray, radiation emitted from radon are
ionizing radiation cause the formation of
chemically active and damaging ions
inside cells and therefore brake DNA strand.
e.g. leukaemia, lung cancer
-UV radiation induce mutations by causing certain
portions of DNA to remain bound together and therefore
result in misreading DNA e.g. .skin cancers
Chemical agents
1. They are benzopyrene ( found in cigarette smoke ),vinyl chloride
(found in plastic industry),aflatoxin( found in certain moulds ),
hetrocyclic amines( found in over-cooked food)
2.Chemical agents causes mutation when they bind to DNA in
the cells.They can modify the two DNA strand and cause incorrect
base pairing during replication
3.Air pollutant ,water pollutant, pollutant in the soil can cause lung
and bladder cancers.
4.Industrial chemical such as benzene ,asbestos aniline dyes and
certain petroleum products are also referred to as occupational
carcinogens as they affect workers in a number of occupations.
Biological agents
1.They are viruses, bacteria, and parasites.
2.Almost all cancer-causing viruses are DNA viruses.
3.Examples are
-Human papilloma virus is responsible for causes of
cervical cancer.
-Hepatitis B virus causes liver cancer.
-Epstein-Barr virus causes cancers of the lymphatic
system and nasopharynx.
Hereditary Predisposition
1. Some cancers ,including those of breast,ovary and colon ,tend to
occur more often in some families than In rest of the population .
2. These are caused by sharing gene traits that are known to contribute
to cancer.
3. Family members share exposure to carcinogens in environment,
such as cigarette smoke or environmental pollutants in a particular
area.
Lifestyle
1. These are referred to habits, diet, and occupation.
2. A nutritious balanced which is high in fibre ,low in ft and
cholesterol,appear to able to reduce the chance of getting
colon cancer and breast cancer.
3. Regular exercise are less likely to develop colon, breast and
prostate cancers.
4. Always exposure to the UV radiation is responsible for cause of
skin cancer.
5. Smoking increases the risk of lung cancer.
6. Alcoholism increases the risk of cancers of the mouth,
oesophagus ,larynx,liver and possibly pancreas.
7. Cervical cancer has been found to be associate with having the
8. first sexual intercourse at early age and exposure to multiple sexual
partners
Ways to reduce the risk of cancers
1 . Avoid tobacco products.
2. Maintain a healthy eating habit
3. Limit consumption of alcoholic beverages.
4. Perform regular exercises
5. Limit radiation exposure.
6. Reduce exposure to the sun.
7 . Beware of body changes.
Cancer screening techniques.
Mammography
Mammography is the available to early detection of breast
disease. There are two types of mammography procedures:
Screening mammography is an X-ray examination of the breast in
a woman. The goal of screening mammography is to detect cancer
when it is still too small to be felt by her physician or the woman.
Screening mammography usually involves two views (X-ray pictures) of
each breast. For some patients, additional pictures may be needed at
screening to include as much breast tissue as possible.
A mammogram shows a malignant
tumor in the breast of a 71-year-old
woman.
Pap smear test
A Pap smear)is a medical procedure in which a sample of cells
from a woman's cervix (the end of the uterus that extends into the
vagina) is collected and spread (smeared) on a microscope slide. The
cells are examined under a microscope in order to look for premalignant ( before-cancer ) or malignant changes.
Global survey of cancer
1 in 3 people will develop cancer during their lifetime, but
cancer is not common in children or young people - it mainly occurs
in the later years of life. Cancers can occur at any age, but the risk of
developing cancer increases with age. Over 70% of all newly diagnosed
cancers occur in people aged 60 years or more.
The most recent statistics for the UK show that for men the
most common cancer is lung cancer (19%), followed by prostate cancer (17%),
large bowel cancer(14%) and bladder cancer (7%). For women the
figures are breast cancer(29%), large bowel cancer (12%), lung
cancer (11%) and cancer of ovary (5%).Many people with cancer
can be cured. Even if a cancer cannot be cured, it can often be controlled
with treatment for months or years
Prevention
Cardiovascular diseases
Cardiovascular diseases refer to the diseases caused by
defect of heart and blood vessels.
Risk factors increase the incidence
of cardiovascular diseases
1.
Age:
The death rate from heat diseases increase with age.
2.Gender:
Men are more likely to have a coronary heart diseases
or stroke than women.
Heredity:
The chance of developing cardiovascular diseases is higher
if parents or siblings had the diseases before the age of 40.
4 . Tobacco smoke :
Smokers’ risk of heart problem is more than twice that of
non- smokers.
5.High blood cholesterol: People who have high cholesterol levels in the blood are
at high risk of plaque formation in the arteries.
6.
High blood pressure:
High blood pressure increase the work load of the
heart,causing its wall to thicken and become stiffer.
7.
Physical inactivity:
8.
Obesity:
The more physically active a person is ,the less
chance the person suffer from cardiovascular
diseases.
People who have excess body fat are more likely
to develop heart disease and stroke
9.Diabetes mellitus:
Diabetes mellitus results in an abnormal high
blood glucose level which speed up
arteriosclerosis and rise the risk of heart attack.
10.Stress:
Stress causes the release of adrenaline which
speed up the heart rate, narrows the blood vessels
and increase the blood pressure.These would
make the heart work harder.
Way to reduce the incidence of
cardiovascular diseases
1.Stopping smoking
2.Doing regular exercise
3.Having a well-balanced diet and maintaining body weight.
4.Minimizing stress
Diabetes Mellitus
There are two type of diabetes mellitus:
1.Type 1 diabetes ( insulin dependent diabetes )
2.Type 2 diabetes ( non-insulin- dependent diabetes)
Type 1 diabetes
Type 1 diabetes is most commonly diagnosed in
children and adolescents, but can occur in adults as well.
It is an autoimmune disorder, in which the body's own
immune system attacks the beta cells in the Islets of
Langerhans of the pancreas, destroying them or
damaging them sufficiently to reduce insulin production.
Patients must rely on insulin medication foe
survival.
Type 2 diabetes
Type 2 diabetes is characterized by "insulin resistance"
as body cells do not respond appropriately when insulin is
present. This is a more complex problem than type 1, but is
sometimes easier to treat, since insulin is still produced in many,
especially in the intial years.Severe complications can result
from unnoticed Type 2 diabetes, including hypertension,
renal failure, and coronary artery disease.
Symptoms of diabetes mellitus
1. Presence of glucose in the urine.
2. Increase the urine output and lead to dehydration.
3. Increase water consumption as patient always thirst.
4. weight loss
5. blurred vision.
6. Lead to lethargy and coma.
N.B. the symptoms of type 2 diabetes develops slowly
Risk factors of Diabetes mellitus
1.Age:
Men or women over age 40 are more likely to
develop type 2 diabetes.
2.Family history:
Type 2 diabetes has strong genetic link.
3.Ethnicity:
Being Aboriginal African, Latin American or
Asian ethnic ancestry are at higher risk of
developing type2 diabetes.
4.Obesity:
Abdominal fat does make the body less
sensitive to insulin.
5.Sedentary lifestyle:
Exercise help lower diabetic risk by
helping to control body fat while maintainin
or improving insulin sensitivity.
6.Over-eating of sugar food:
High-sugar diet might worsen glucose
tolerance.
Biology principle of control
1. Getting a diabetic diet.
--The diet low in saturated fat ,sugar, salt,high in fibre,
vegetable and fruits.Carbohydrates should be spread
throughout the day.Avoid eating candy cookies and other
sugar foods and drink.
2.Reducing body weight.
3.Carrying regular exercise.
4.Taking medicine.
5.Always monitoring blood glucose.
---Measure blood glucose level once or twice a day
Risk factors common to major Noncommunicable conditions
Conditi
on
Risk
factor
Cardiovasc
ular
Disease*
Diabet
es
Canc
er
Chronicobstructive
pulmonary
Disease
Smokin
g
4
4
4
4
Alcohol
4**
Physical
Inactivit
y
4
4
4
Obesity
4
4
4
Blood
pressur
e
4
4
Dietary
fat/Bloo
d lipids
4
4
4
Blood
glucose
4
4
4
4
4
* Including hypertension
**A U-shaped relationship with risk for cardiovascular disease is present for alcohol.
The End