Heart

... nerve to the sinal-atrial node (SA node) which responds by increasing the rate at which it sends out waves of excitation therefore increasing heart rate. When receptors in the aorta and carotid artery are stimulated, it indicates that there is a distension of these vessels as a result of ... greater than if the subject was lying down. Therefore the stoke volume would be greater than if the subject was standing vertically, therefore the heart rate would consequently decrease. Another important factor in explaining my results is the influence of carbon dioxide. When doing any form of exerc...

• Word Count: 2184
• Approx Pages: 9
• Grade Level: High School

... entire body. The pulmonary valve, like the aortic valve, has a semilunar shape and a unidirectional function. CORONARY CIRCULATION The blood supply to the heart muscle is furnished mainly by the CORONARY ARTERIES, which originate from the aorta immediately after the aortic valve. These vessels pass through the fatty tissue ... metabolic rate fluctuated with the environmental temperature, they did not need as efficient a circulatory system as mammals and birds. The two-chamber heart is retained by modern fish, but oxygen-rich blood does not mix with oxygen-poor blood, because the blood i...

• Word Count: 1823
• Approx Pages: 7
• Grade Level: High School

... region. Sometimes the pain may not be in your chest at all; maybe neck, arms, back, and abdominal region so beware. One heart disease is called Chronic Stable Angina Pectoris, chronic meaning relatively safe, angina refers to discomfort with coronary artery disease. It means more like squeezing ... our nerve tissue functional, and to synthesize steroid hormones. (S.B., P.246) Cholesterol build up in a coronary artery can block blood flow to the underlying heart muscle, usually when 70 percent or more of the inner vessel diameter is obstructed chest discomfort occurs, Angina. (R.T., P.16) ...

• Word Count: 1965
• Approx Pages: 8
• Grade Level: High School

... region. Sometimes the pain may not be in your chest at all; maybe neck, arms, back, and abdominal region so beware. One heart disease is called Chronic Stable Angina Pectoris, chronic meaning relatively safe, angina refers to discomfort with coronary artery disease. It means more like squeezing ... our nerve tissue functional, and to synthesize steroid hormones. (S.B., P.246) Cholesterol build up in a coronary artery can block blood flow to the underlying heart muscle, usually when 70 percent or more of the inner vessel diameter is obstructed chest discomfort occurs, Angina. (R.T., P.16) ...

• Word Count: 1965
• Approx Pages: 8
• Grade Level: High School

... potassium. The increased intracellular potassium hyperpolarizes the membrane potential and slows the repolarisation of the pacemaker potential, making the time period between action potentials greater and the heart rate falls. There is very little parasympathetic negative inotropic innervation to the ventricles, but drugs such as propranolol which act as '-adrenoreceptor antagonists ('-blockers) do reduce ... . The cardiac output is intrinsically linked to the pulmonary and ventilator systems through peripheral chemoreceptors, and has a directly proportional relationship, when ventilatio...

• Word Count: 1504
• Approx Pages: 6
• Grade Level: Undergraduate

... such as fruits, vegetables and whole grains) and low in fats, saturated fats and simple sugars, contributes to desirable cholesterol and triglyceride levels, adequate nutrition, and decrease the risk of heart disease (Lazarre, 2003). "Studies have shown that so-called Third World diets, which consist of grains, fruits, and vegetables, result in lower blood cholesterol levels. In the United States ... and northern Europe, where people consume large amounts of meat and dairy products, extremely high rates of heart and circulatory disease are present. Even children in these nations show sig...

• Word Count: 2485
• Approx Pages: 10
• Has Bibliography

... coronary sinus into the right atrium. A small amount of blood drains directly into the right atrium by the way of the cardiac veins."# The heart is supplied by two major coronary arteries, the right and the left. The left coronary divides into two branches; the anterior interventricular and the circumflex ... branch. The right coronary supplies the sinoartrial node (SA node) or pacemaker of the heart. When this vessel loses its ability to supply the node, a person usually needs to have a pacemaker placed in their thoracic wall to take the ... place of the original pacemaker. Another im...

• Word Count: 1235
• Approx Pages: 5

... artery. The fat particularly consists of cholesterol and other materials in the blood such as compounds that facilitate clotting. As the fat builds up, the artery narrows, restricting blood passage. Heart attacks occur due to many other causes such as nutrition, smoking, excessive alcohol use, mental stress, high blood pressure, diabetes, inactive leisure time, and multiple risk factors. Firstly, ... ) produced in the body. Usually people with adult-onset diabetes are over weighted. Adult onset-diabetes is a significant risk factor of development of high blood pressure, and other heart an...

• Word Count: 1823
• Approx Pages: 7
• Grade Level: High School

... until 2005. It was discover that more than 90 percent are post-menopausal women, possibly because lower levels of the hormone estrogen make the heart cells in some women more vulnerable to an adrenaline rush. There are many names for the condition such as, stress cardiomyopathy, stress-induced ... cardiomyopathy, and apical ballooning syndrome. Causes The exact cause of broken heart syndrome is unclear. It is thought a surge in stress hormones, such as adrenaline, might be temporarily damage the hearts in some people. How ... some of the symptoms: Chest pain (angina) Shortness of breath...

• Word Count: 708
• Approx Pages: 3
• Has Bibliography
• Grade Level: High School

... the beginning of the lab, we acquired a Daphnia from a tank of water with a syringe. Placing the Daphnia on the microscope, we then recorded it's heart rate four different times for fifteen-second intervals. After these trials were complete, we then repeated it. However, this time, we put the Daphnia in "unknown ... this portion of the trial was finished, we again started another set of trials. This time, we gave the Daphnia "unknown 2"". We again recorded its heart rate four different times at fifteen-second increments. At the end of the solution trials, we put the Daphnia in water, an...

• Word Count: 594
• Approx Pages: 2
• Grade Level: High School