6.2 Evaluate the effects of smoking on body systems.

Smoking has a devastating effect on your body, not only medically but physically too. Smoking can damage different areas of your body in different ways just with the harmful chemicals. Nicotine is a drug that stimulates your brain cells, it also causes narrowing of the blood vessels that increases blood pressure, this then makes the heart work harder which can result in an atheroma or a blood clot.Carbon monoxide is a gas that leaves you feeling breathless, tar is a sticky substance (one being carcinogen) that are cancer producing. It stops cilia mucous membranes from moving this causes them to build up with mucus. Coughing can damage alveoli resulting in emphysema; this is a serious condition as it prevents gaseous exchange taking place. ‘The chemicals inhaled by smoking can effect the electrical and chemical process in which the brain relays messages though the central nervous system’. (http://www.smokefreereality.com/effects.php)

Smoking affects our bodies in many ways:·

• Skin becomes thinner and fine lines and wrinkles occur·
• Loss of sense of smell and taste.·
• More likely to develop cancer in the mouth and larynx.·
• More likely to develop cancer of the trachea.·
• Some cilia are destroyed or damaged.·
• More likely to get bronchitis.·
• Persistent coughing can lead to emphysema.·
• Twice as likely to have a heart attack.·
• More likely to develop lung cancer.·
• More likely to develop stomach cancer.·
• More likely to develop ulcers.

By stopping smoking it can have almost instant results on helping your body recover and over time you can repair your body and prevent long term illnesses and diseases.(Wright, D (2000) Human Physiology and Health, Cambridge publishing management, page 52

6.1 Analyse the relationships between a) Smoking and coronary heart disease b) Smoking and lung cancer.

Lung cancer can take years to develop however by stopping can decrease your chances of developing because as time goes on the abnormal cells begin to replace themselves with normal ones.Soon after exposure to inhaling nicotine and other substances a few abnormal cells may appear in the lining of the bronchi, gradually more and more abnormal cells will develop and may become cancerous.Smoking is one of the major causes of cardiovascular disease and you are more likely suffering a heart attack if you do smoke. Smoking has devastating affects on your body resulting in many health problems but mainly causing coronary heart disease and lung cancer.Smoking causes damage to the lining of your artery, leading to fatty material and casing a restricted passage for the blood to pass through. Carbon monoxide in cigarettes reduces oxygen in the blood and being carried to the heart and body. Chemicals in cigarettes produce adrenaline; this encourages the heart to beat faster and raising blood pressure. Smoking also makes your blood more susceptible to clot. The relationship is that smoking causes these effects on the body which can lead to coronary heart disease of mutation of the cells causing cancer (www.britishheartfoundation.co.uk)

5.2 Discuss the relationship between diet, blood pressure, blood cholesterol and circulatory disease.

Having a healthy and stable diet will prevent high blood pressure, high blood cholesterol and circulatory disease. This is because what you eat and drink can has a real effect on your body, the healthier your eating habits are, the lower your blood pressure will be. The less salts and fats you have in your diet the healthier your arteries will remain. All these habits have a knock on effect on your body because by having a poor diet you have a higher risk of the fats building up in your arteries, causing the passage ways to become narrow and restricting the flow of oxygen reaching your body. This then causes blood pressure to increase and the rate of blood will start to race faster maybe becoming blocked causing aneurysm, athomas or a blood clot, these all results in circulatory disease.Also by having a poor diet you are more likely to become obese, obese people are less likely to exercise and this puts enormous pressure on the heart and circulatory system.

5.1 Describe the changes in artery structure associated with circulatory disease.

A healthy artery is made up of several thick layers with elastic tissue walls; the lumen in the middle is a nice big, hollow space. When an artery becomes disease the structure starts to change. The endothelium is usually smooth and unbroken; damage is caused by high blood pressure. White blood cells and lipids in the blood stick together under the lining to form a fatty pouch. Overtime this occurs and builds up and hardens o form a fibrous plaque called an atheroma. The plaque blocks the lumen of the artery and restricts blood flow, causing blood pressure to increase.Atheromas increase the risk of other circulatory disease such as Aneurysm, Thrombosis and Angina all of these can have serious implications. Aneurysm changes the structure of the artery as they become weak and damaged. The inner lining of the artery gets pushed out to form a balloon shape swelling this may result to it bursting or hemorrhaging.Thrombosis ruptures the inner lining leaving a rough surface. Platelets and fibrin accumulate and form a blood clot, but the blood clot can cause a complete blood clot in the artery.Angina causes chest pain as it restricts the oxygen; the coronary arteries become narrow reducing oxygen to parts of the muscles.

4.2 Explain the processes for redistributing blood during exercise.

When you exercise, the blood vessels dilate and the blood is able to flow better. As energy gets used up by your muscles, the muscles produce carbon dioxide. By products cause the capillaries within the muscles to expand and increased blood flow delivers more oxygenated blood to the working muscles.When your body becomes under pressure from exercise, blood that would have gone to other organs goes to the muscles instead. This happens by the sympathetic nervous system stimulating the nerves to the heart and blood vessels, this causes blood vessels (arteries and veins) to contract and constrict. The vasoconstriction reduces blood flow to tissues and concentrates on the muscles (http://health.howstuffworks.com/sports-physiology9.htm).

4.1 Explain the mechanisms for regulating ventilation and pulse rates.

Your heart rate and breathing is controlled by the sympathetic and parasympathetic nervous system. The effect of exercise is to speed up the heart rate and increase the breathing which happens when the sympathetic nerves transmit signals to the SA node and this stimulates the release of adrenalin from the adrenal medulla situated at the top of the kidneys and released by the sympathetic neurons. This happens when the body becomes under pressure, the body realises that oxygen is needed in certain parts of the body and energy is needed to be released. The heart rate increases and breathing becomes deeper in an attempt to get oxygen pumping round the body quicker. A similar thing occurs when you react to a situation, it maybe a stressful situation or a frightening experience as this is the body’s way of survival. When your body becomes under pressure the breathing and the heart rate increases but so does your blood pressure. These messages are located in the aorta and carotid artery and then received by the cardiac centre, this responds by sending out impulses via the parasympathetic nerves to the SA node and the heart rate slows down.When the body no longer feels under threat the parasympathetic nervous system kicks in striving for homeostasis and regulating heart rate and breathing.

3.4 Calculate cardiac output and discuss the importance of this value.

Cardiac output is the volume of blood that the heart is able to pump. When the ventricles contract, about 70-90 cm3 of blood is ejected into the pulmonary artery and aorta. This represents the volume of blood being pumped round the body; this is an important factor in determining the effectiveness of the heart. It may indicate problems such as heart failure or poor circulation. There are two major factors that contribute to the cardiac output and that is heart rate (number of heat loads being pumped round the body per unit of time) and the stroke volume (the volume of blood the heart can fill with per contraction). Cardiac output = heart rate x stroke volume. The stroke volume is regulated by stimulation from the sympathetic nervous system.By increasing the heart rate effectively increases the cardiac output by increasing the volume of blood released in the body. As long as the heart is given enough time at diastole the effective volume that the heart outputs will increase.If the cardiac output is too low then this means that the body is not being supplied with enough blood which could lead to heart failure of other life threatening problems.Problems are usually recorded by attaching electrodes to a machine that can amplify and record an ECG (electrocardiogram). As the cardiac impulse travels across the atria and ventricular walls its electrical activity produces a recorded trace.(http://bme.usc.edu/bme403/Section_3/cardiac_output.html)