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)

3.3 Describe the cardiac cycle and explain the electrical activity of the heart during a heart beat.

Cardiac Cycle

Deoxoygenated blood enters the body into the right atrium via the Vena cava. Tricuspid valve closed.

Once the blood has entered, the blood is pushed down into the right Ventricle. The Pulmonary valve opens.

The blood then pumps up through the Pulmonary Artery to the Lungs where gaseous exchange takes place and carbon dioxide diffuses out of the blood and oxygen is diffused in from the lungs.

The oxygenated blood is returned to the heart via the pulmonary Vein into the left atrium. Bicuspid Closed, cardiac muscle contracts and Bicuspid valve opens

The blood is pumped down into the left ventricle.

The blood is pumped from the left ventricle up through the Aorta and is pumped around the body providing oxygen to all the organs. Aortic valve opens.

Then this process happens again.

Your heart’s electrical system is made up of three main parts:
The Sinoartrial (SA) node, located in the right atrium.
The Artrioventicular (AV) node, located on the septum close to the tricuspid valve.
The His-Purkinje System, located along the walls of your heart’s ventricles.

Each beat is controlled by an alectrical signal from within your heart muscle. In a healthy heart, each beat begins with a signal from the SA node. His is called your heart’s natural pacemaker. Your pulse is the number of signals the SA node produces per minute.
(http://www.nhlbi.nih.gov/health/dci/Diseases/hhw/hhw_electrical.html)
The upper chambers are stimulated; this follows by a slight delay to allow the two atria to empty. Then the two ventricles are electrically stimulated.

3.2 Describe the structure of the heart.

The heart is hollow and is said to look like ‘an upside down, pear shape shell’. It consists of three layers the epicardium, this is the thin outer layer that is smooth and has a slippery texture. Myocardium, this is made up of strong cardiac muscle fibers which are connected to the electrical synapse and this is responsible for the pumping action and the endocardium this is the inner lining which contains large blood vessels in which the heart connects to. The inside of the heart is divided into four chambers, the left and right atria and the left and right ventricles, which fills with blood and empties. The two atria’s form part of the top curve and the two ventricles form a base.
The heart is separated into left and right side by the septum. A valve connects each atrium to the ventricle below.
The bicuspid valve connects each atrium to the ventricle and the tricuspid valve connects the right atrium to the right ventricle (http://www.integrativebiology.ox.ac.uk/heartrefs.html).
Blood flows from the right ventricle to the pulmonary artery and to the lungs.
The aortic is between left ventricle and blood flows into the left ventricle to the aorta and to the whole body. Nodes are responsible for the heart beat and control the rhythmic sequence of contractions. They are called sinatrial nodes and artioventricular nodes ventricular.

3.1 Relate the structure of the arteries, veins and capillaries to their functions.

(http://www.phschool.com/science/biology_place/biocoach/cardio2/structure.html#map)

2.3 Explain the transport of oxygen and carbon dioxide by the blood.

Oxygen is inhaled into the lungs via breathing and together with haeoglobin found in red blood cells. The haemoglobin then transports the oxygen to cells that need it and releases it. Carbon dioxide is then picked up and carried back to the lungs where most of it is exhaled. Carbon dioxide diffuses from the tissues into red blood cells where it is combined with water to form carbonic acid.
Oxygen going into the lungs then diffuses into the blood stream through the pulmonary circulation and to the left side of the heart. Oxyhaemoglobin in as cellular respiration and energy is released or known as gas exchange. Carbon dioxide is released and diffuses into the blood stream and flows to the right side of the heart and through the lung and out into the atmosphere.
The aortic is between left ventricle and blood flows from the left ventricle to the aorta and to the whole body. Nodes are responsible for the heart beat and control the rhythmic sequence of contractions. They are called sino-atrial and artio ventricular.

2.2 Relate the structure of the red blood cell to its function.

The Red blood cell also known as Erythrocytes has many important roles to play in our body. The main function is to carry oxygen from the lungs to the tissue in your body and take the carbon dioxide from the tissues to the lungs so it can be breathed out. The structure of the RBC plays a key role in effective use as it is biconcave in shape this gives it the flexibility, because it is very flexible it means it can bend and twist through the blood vessels. Without the ability to flex they would get stuck and cause problems in your circulation. A RBC is tiny, only 1/25,000 of an inch in size and your blood contains 25 trillion, replacing them constantly. Red Blood cells are made in the red bone marrow and in adults can be produced in the thoracic bones, vertebrae, cranial bone and the ends of the femur and humorous bones. Red blood cells do not contain a nucleus, this means they cannot reproduce. After 120 days they are ingested by phagocytic cells in the liver and the spleen and then the body replaces them. Erythrocytes are known as red blood cells because of a substance called haemoglobin, haemoglobin are composed of simple protein and iron pigments and when combined with oxygen their colour becomes bright red.

2.1 Describe the constituents of plasma and explain their functions.

Blood is a specialised tissue and is the only tissue in your body that flows. Plasma is the liquid part of blood and it consists of clear water and other solutions such as nutrients like glucose, fats and amino acids. It also contains important chemicals such as sodium, potassium and calcium, special proteins such as fibrinogen, albumin and various globulins that produce antibodies and hormones.
The role of the plasma is the body is to transport food and oxygen to the cells in parts of the body and carries waste away from the cells. It also helps with homeostasis by maintaining the body’s chemical balance and keeps a stable internal environment.
Blood consists of three cellular components red blood cells (RBC’s also known as erythrocytes), White blood cells (WBC’s also known as leukocytes) and Platelets.

White blood cells activate antibodies that go to work destroying any bacteria, virus, fungi or parasite entering the body. Red blood cells have an important job of picking up oxygen in the lungs and transporting it to the rest of the body. Platelets are fragments of cells responsible for clotting they are vital to people when they cut themselves as this clots the blood and stops you bleeding. When the platelet touches the roughened edges of the torn blood vessel, they burst open releasing chemicals that set off a reaction in the blood leaking out. The convert one of the plasma’s protein’s Fibrinogen into a network of fibers that trap Red blood cells and they form a clot to seal the leak (http://www.nsbri.org/HumanPhysSpace/focus3/earthphys-frame.html). Red blood cells and Plasma plays an important role in transportation. They all play a part in regulating the body.

1.3 Discuss the role of the nervous system in generating the normal breathing rhythm.

The brain controls all bodily functions and the nervous system is a network that relays messages from the brain to the different parts of the body. Breathing is controlled by two centers in the brain, the Medulla Oblongata and the Pons. These are often called Brainstem and are responsibly for the body’s automatic functions such as breathing, heart rate, blood pressure, swallowing, digestion and blinking. The Medulla Oblongata acts as the survival action of breathing and is a voluntary action. The Pons deals with the control of deep breathing (http://kidshealth.org/parent/general/body_basics/brain_nervous_system.html#).
The nervous system depends on lots of tiny cells called neurons, neurons relay information by making connections and affect the way we learn, move and behave.
The nervous system offers sensors located in the aortic arch and these sense if the body has too much carbon dioxide or not enough oxygen. These also stimulate the parasympathetic and the sympathetic system. The sympathetic system speeds up the heart allowing more blood and oxygen to flow to parts of the parts of the body faster and then the parasympathetic system licks in ad the medulla Oblongata takes over and puts the breathing and the heart rate back to normal.

1.2 Evaluate the conditions required for effective gaseous exchange.

Gas exchange is the movement of oxygen into the bloodstream and carbon dioxide out of the bloodstream. Inside the lungs, gas exchange takes place between the air and the blood. This process is called Diffusion.
For effective gaseous exchange to take place there are certain requirements needed. The Lungs are attached to the inner chest wall surface by pleural membranes, between these are pleural fluids. The pleural fluid keeps the lungs moist to allow flexibility and prevents friction (www.bbc.co.uk/dna/hzg2/A27019505).
The alveoli provide a very large surface area in which a greater amount of gaseous exchange can take place. The alveolus is 1 cell thick allowing for the diffusion to happen easy. The lining of the alveoli are kept moist because in order for the gases to be defused across the membranes they need to be in solution. Each alveolus is supported by a network of blood capillaries; these carry the incoming oxygen away quickly maintaining a diffusion gradient (Wright, D (2000) Human Physiology and Health, Cambridge publishing management, page 52). If the surface tension of the alveoli walls is too high then it reduces the airflow and this means oxygen is not getting transported to the capillaries but if the surface tension is too low then this results in the alveoli becoming floppy during exhalation and decreases ventilation. Your body constantly fights to maintain balance and homeostasis in order for this to happen the oxygen levels inside the body need to remain high and the carbon dioxide needs to able to disperse. The concentration gradients across the respiratory surface are the boundary between the external environment and the interior body.

(http://www.biologymad.com/master.html?http://www.biologymad.com/GaseousExchange/GaseousExchange.htm

1.1 Relate the structure of the Respiratory System to the process of Ventilation.

Respiratory ventilation is the process that forces air in and out of our airways. The air penetrates deep into our lungs and is repeated. The nose, mouth, pharynx, trachea, bronchi and bronchioles form the airway that conducts air in and out of the lungs. (http:/sonnet.nottingham.ac.uk/rlos/bioproc/ventilation/index.html)