Physiology Health Exercise z Physiology and diseases of

Physiology, Health & Exercise z Physiology and diseases of the cardiovascular system z. Energy balance and obesity z. Pathophysiology of Diabetes Mellitus z. Pathophysiology of Osteoporosis

Introduction z Exercise has wide ranging effects on the body and the mind. z In particular, it can reduce your risk of major diseases such as coronary heart disease (CHD), stroke, obesity, Diabetes Mellitus and Osteoporosis. z An active lifestyle will not only reduce your risk of developing these diseases but also give you a sense of well being and confidence. 2

Structure & Function of the cardiovascular system z The heart is the central organ of the CVS pumping blood to the lungs and the other tissues of the body. z The primary purpose is to move substances around the body z The blood can only reach these tissues by passing through blood vessels, the other vital component of the CVS. z The CVS supplies all the cells of the body with nutrient and oxygen-rich blood and removes carbon dioxide which would otherwise kill cells. 3

Heart Structure z 4 chambers z Atria at top z Ventricles at bottom z Muscular pump composed of cardiac muscle z Can beat without input from the nervous system 4

Heart Structure z The cardiovascular system is closed as blood is transported within blood vessels. z It is also described as a double circulatory system because in one complete circulation of the body blood goes through the heart twice. z The left ventricle wall of the heart is thicker than the right as it is pumping blood around the whole body compared to only the lungs. 5

Heart Structure z Having a double circulation reduces the time taken for the blood to circulate the whole body and allows mammals to have a higher basal metabolic rate (BMR) z The right side (RA) of the heart receives deoxygenated blood from the body and it passes it to the lungs to be oxygenated. z The left side (LA) receives oxygenated blood from the lungs and passes it to the rest of the body. 6

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Pulmonary circuit Pulmonary artery RV Pulmonary vein lungs LA 10

Systemic Circuit Major organs Aorta LV Vena Cava RA 11

Valves of the Heart z The valves between the atria and ventricles are known as atrio-ventricular valves (AV valves) as they prevent the back flow of blood into the atria when the ventricles contract. z Between RA & RV- tricuspid valve (3 flaps) z Between LA & LV- bicuspid valve (2 flaps)- also called mitral valve 12

Valves of the Heart z The semi-lunar valves are found at the origins of the pulmonary artery and aorta. z Between RV and pulmonary artery- pulmonary valve z Between LV and aorta- aortic valve z Open when ventricles contract to allow blood flow into the arteries z Close when arterial pressure falls to prevent blood flowing back into the ventricles when they relax. 13

Valves of the Heart z The heart valves closing cause the lub-dub sound heard with a stethoscope z A “heart murmur”“sloshing sound” as valves not closing properly 14

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Heart Dissection z Heart dissection 16