F 7 Biology AssignmentTopic: 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

a. Cancersb. Cardiovascular diseasesc. Diabetes mellitus

Example:

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

Figure 1. Schematic diagram of benign and malignant tumours

Benign Tumour1. 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 Tumour1.Malignant tumours are life threatening2.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 increasethe 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 agents1. 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 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. 

Mammography

A mammogram shows a malignant tumor in the breast of a 71-year-old woman.

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 pre-malignant ( before-cancer ) or malignant changes.

Pap smear test

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

diseases1. 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: The more physically active a person is ,the less chance the person suffer from cardiovascular diseases.8. Obesity: 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 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 1 diabetes

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 loss5. 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 maintaining 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 conditionsConditionRisk factor

Cardiovascular

Disease*

Diabetes

 Cancer

Chronic-obstructive pulmonaryDisease

Smoking

4 4 4 4

Alcohol 4**   4  

Physical Inactivity

4 4 4  

Obesity 4 4 4 4

Blood pressure

4 4    

Dietary fat/Blood lipids

4 4 4  

Blood glucose

4 4 4  

* Including hypertension **A U-shaped relationship with risk for cardiovascular disease is present for alcohol.

The End