The heart flow Valves in the heart • There are 4 valves you should know for this exam: These are also called ATRIOVENTRICULAR valves: 1. Bicuspid or Mitral valve (left) 2. Tricuspid valve (right) These two are also called SEMILUNAR valves: 3. Aortic semilunar valve 4. Pulmonary semilunar valve What do valves do? • They prevent backflow of blood in the heart. We also find valves in veins where they prevent backflow of blood as veins do not have the pressure arteries do to push blood throughout the body. This is what these valves look from the top: Remember!!! If you don’t remember Tricuspid and Bisuspid, you can use the word atrioventricular (left or right). Same thing applies for the aortic and pulmonary valves, you can use semilunar instead, or viceversa. How blood flows through the heart. The right side of the heart receives and pumps DEOXIGENATED BLOOD The left side of the heart receives and pumps OXIGENATED BLOOD RIGHT SIDE LEFT SIDE A systole is a contraction. When the atria contract the tricuspid (L) and bicuspid (R) valves open. When the ventricles contract, they open the semilunar valves and they push blood out into the aorta and the pulmonary artery. In other words… • Atria contract (ventricles relax) = 1. Bicuspid and tricuspid valves open 2. Ventricles are relaxed and they receive blood. • Ventricles contract (atria contract) = 1. Bicuspid and tricuspid valves close 2. Pulmonary and aortic semilunar valves open Human circulation is double because blood passes twice through the heart for each complete circuit of the body. - Pulmonary circulation- blood goes from the heart to the lungs and back to the heart. - Systemic circulation- blood goes from the heart to the body and back to the heart. How blood flows through the circulatory system: (look at the diagram as you follow the path of blood shown below) Vena cava- right atrium- tricuspid valve (atrioventricular valve) - right ventricle- semilunar valves (pulmonary)- lungs- pulmonary vein- left atria- bicuspid valve (atrioventricular valve) - left ventricle- semilunar valve (aortic) – aorta- body……….. Back to vena cava Coronary heart disease • The coronary artery becomes blocked. • The heart muscles does not get glucose and oxygen. • It starts respiring anaerobically and as a result lactic acid is being produced- this produces angina (pain in the chest). • If the heart stops contracting, a heart attack happens. Coronary heart disease 1. Poor diet- high in cholesterol 2. Poor lifestylesmoking, lack of exercise, stress 3. Genetic factorshaving a family history of heart disease. Men are more at risk of CHD than women. Coronary heart diseaseWays to deal with it 1. A healthy lifestyle a) Exercise - prevents blocked arteries (thrombus formation) - lowers blood pressure - lowers cholesterol / lowers fats / reduces risk of atheroma ; - weight loss / using fats / avoids obesity ; - lowers stress ; - (heart) muscle stronger / lower (resting) pulse ; b) No smoking Nicotine is found in plaque (atheroma) c) Diets Reducing the amount of saturated fats/ cholesterol in our diets- they also contribute to the plaque that blocks the arteries. Coronary heart diseaseWays to deal with it 2. ANGIOPLASTY Keywords - Atheroma or plaque - Stent - Blood flow Coronary heart diseaseWays to deal with it 3. Coronay Bypass When the coronary artery is blocked, a blood vessel can be taken from another part of the body (example- leg) and connected to the aorta and the unblocked part of the coronary artery. This increases blood flow to the heart.