Disease

WHat happens in coronary heart disease?

* Layers of fatty materials build up inside the coronary arteries, narrowing them.
* This reduces the flow of blood through the coronary arteries, resulting in a lack of oxygen for the herat muscle.

Treatment of coronary heart disease

* stents can be used which keeps the heart open.
* Statins are widely used to reduce blood cholestrol levels which slow down the rate of fatty material deposit.

Advantages and disadvantages of stent.

Advantage:

* blocked artery is held open
* blood flow to heart muscle cells is increased
* stent will remain in place for a long time
* effect of stent is immediate
* rapid recovery from operation

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Disadvantage:

* risk of infection from operation
* risk of surgery eg heart attack or bleeding
* risk of thrombosis or blood clot

Advantages and disadvantages of statin

Advantages of statins

* easy to take or not invasive (procedure)
* decrease blood cholesterol
* slow down build-up of fatty materials in arteries
* maintain blood flow to heart muscle cells
* low cost (compared to stent operation)

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Disadvantages of statins

* might be side effects of drug eg muscle pain
* effects take time to happen
* drug will need to be taken long term
* might forget to take drug

Consequences of faulty valves.

* Valves can stiffen which can prevent them opening fully to let blood flow through
* This reduces the volume of blood pumped by the heart

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* Sometimes a faulty heart valve might develop a leak
* This allows blood to flow from the ventricles to the atria or the arteries to the ventricles

communicable disease

**Communicable** diseases are caused by **microorganisms** called **pathogens** which can **spread** between individuals or individuals and animals

Non-communicable disease

* Non-communicable diseases are not caused by pathogens and their effects on health tend to be **longer-lasting**; examples are **asthma**, **CHD** and most **cancers**

health

health is the state of physical and mental well-being

How may disease interact? (not needed to memorise just for knwoledge)

* defect in the immune system means that an individual is more likely to suffer from an infectious disease
* viruses living in cells can be a trigger for cancers
* immune reactions initially caused by a pathogen can trigger allergies such as skin rashes and asthma
* severe physical ill health can lead to depression and other mental illness.

Interactions and risk factors (not needed to memorize just for knwoledge)

* the effects of diet, smoking and exercise on cardiovascular disease
* obesity as a risk factor for type 2 diabetes
* the effect of alcohol on the liver and brain function
* the effect of smoking on lung disease and lung cancer
* Thee effect of smoking and alcohol on unborn babies
* carcinogens, including ionizing radiation as a risk factor for cancer.

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Cancer

the reasult of changes in cells which leads t uncontrolled growth and division.

Benign tumors

growth of abnormal cells which are contained in one area, usually within a membrane

do not invade other parts of the body

Malignant tumor

* cancers – the cells invade neighbouring tissues and spread to different parts of the body via the blood where they form secondary tumours
* Malignant tumours are more likely to disrupt the functioning of the organ they originate in (as they invade healthy tissue) and the organs they spread to –

(this is why they are dangerous and how they lead to death)

Why does a heart attack survivor struggle with exercise afterwards?

* heart muscle cannot contract / pump as effectively * so less blood pumped out of heart or to body (on each beat / contraction) * so less oxygen reaches cells for aerobic respiration * so breathing rate increases to supply more oxygen to repay oxygen debt