Non- communicable diseases

Risk factors that are linked to an increased rate of disease

• age
• genetic make-up
• diet, obesity, level of exercise
• inhaling carcinogens from tobacco smoke
• environmental factors - ionisng radiation, uv light from the sun, second hand tobacco smoke

Casual mechanisms

Sometimes a scientist can see a link between two factors - a rise in one factor might lead to a rise or fall in the other 

example : the more cigarettes a person smoked , the more chance of developing lung cancer = a correlation between smoking and lung cancer

Casual mechanism - how one factor influences another through a biological process

Tumours

Tumour = a mass of abnormally growing cells 

Benign tumour grows in one place - can be dangerous if it grows in the brain and compresses it

Malignant tumour can spread to healthy tissue, cancer is a type of malignant tumour 

Secondary tumours = when maligant tumours enter the blood stream and circulate to otehr parts of the body

Causes of cancer include:

• genetic factors - breast cancers
• mutations in genes caused by carcingens 
• ionising radiation - uv light causes skin cancer
• virus infections - hpv causes cervical cancer

Cancers can be treated by radiotherapy and chemotherapy

Tobacco smoke contains:

• nicotine - addictive substance - raises heart rate 
• carbon monoxide - toxic gas, replaces oxygen in red blood cells
• tar - sticky black substance, is carcinogen
• chemicals that anesthetise in cillia in the airways - prevents them from wafting up mucus

Problems caused by smoking

• blood carries less oxygen around the body - bc of carbon monoxide attaching to red blood cells - leads to breathlessness
• if a pregnant woman smokes, baby will also recieve less oxygen, premature birth, low birth weight or stillborns 
• muscus containing dirt and pathogens builds up in airways bc it is not removed - infecting and coughing
• tar can damage the alveoli - causes chronical obstructive pulmonary disease (COPD) - causes severe breathlessness and death
• causal link between smoking and cardivascular disease - hearth attacks and strokes

weight and amount of exercise you do can affect the risk of developing various diseases

eating too much food leads to overweightness and possibly obese

obesity can lead to type 2 diabetes, high blood pressue or heart disease

people who exercise regularly have bigger hearts, bigger muscles and bigger lungs 

regular excersie reduces the risk of developing cardiovascular disease:

• by lowering blood cholestrol and reducing fatty deposits in the blood vessels 
• by building muscle tissue, which improves metabolism rate, less likely to be overweight
• by improving bloody supply to the heart so the heart is fitter

Alcohol enters blood stream and goes to liver and brain

large amounts of alcohol affects the nervous system, slowing reactions, reflexes andthought processes- large amounts can cause death

heavy drinking can cause the liver to become damaged, person may have cirrhosis caused by a scar tissue in the liver - long term drinking can cause liver cancer

long-term alcohol abuse can also cause damage to the brain

if a pregnant woman drinks alcohol it can pass through the placenta to the fetus - can cause physical problems such as facial deformities and heart problems, after birth the baby might have developmental and learning problems - called fetal alcohol syndrome 

Ionising radiation - uv light from sun, radon gas, medical & dental x-rays 

radiation penetrates the cells and damages the chromosomes - leads to mutations in the DNa