Circulatory System Syllabus Notes PDF

Circulatory System 1. Identify and describe the structure and function of the parts of the circulatory system including atria, ventricles, atrioventricular valves, semi-lunar valves, septum, papillary muscles, tendinous chords, apex, aorta, vena cava, pulmonary artery, pulmonary vein, an...

Circulatory System 1. Identify and describe the structure and function of the parts of the circulatory system including atria, ventricles, atrioventricular valves, semi-lunar valves, septum, papillary muscles, tendinous chords, apex, aorta, vena cava, pulmonary artery, pulmonary vein, and carotid artery Part Structure and Function Atria Top chamber of hearts - Left atrium receives oxygenated blood from lungs and pumps to left ventricle - Right atrium receives de-oxygenated blood from superior and inferior vena cava and pumps to right atria Ventricles Bottom chambers of heart - Left ventricle receives oxygenated blood from left atria and pumps to lungs - Right ventricle receives deoxygenated blood from right atrium Atrioventricular valves Valves between atria and ventricles that ensure blood flows through it in only 1 direction - Tricuspid valve between right atrium and right ventricle - Mitral valve/bicuspid valve is between left atrium and left ventricle Semi-lunar valves Valves within heart that prevent backflow of blood - Pulmonary valve is between right ventricle and pulmonary artery - Aortic valve is between left ventricle and aorta Septum Partition between left and right sides of heart Papillary muscles Muscles in the ventricles of the heart that anchor the valves Tendinous chords Strong, fibrous connections between valve leaflets and papillary muscle. Apex The pointed part of the heart between tip of left and right ventricles Aorta Main artery that takes blood to all parts of body Vena cava A pair of major veins that bring blood in from body. - Superior brings blood from head and upper body - Inferior brings blood from lower body and legs Pulmonary artery Blood vessels that carry oxygen-poor blood from the right side of your heart to your lungs Pulmonary vein The vein that transports blood from the lungs to the left atrium Carotid artery A pair of blood vessels that deliver oxygenated blood to head and brain. 2. Describe and explain the movement of blood through the heart (the cardiac cycle) and into the pulmonary and systemic circulations Cardiac cycle: is the sequence of events that occur in 1 complete beat of the heart. Systole: pumping phase of cycle when heart muscles contract Diastole: filling phase of cycle when muscle relaxes Atrial systole: contraction of atria forces remaining blood into ventricles Ventricular systole: atria relaxes and refills, ventricles contract and force blood into arteries Dub sound – closing of aortic and pulmonary valves after ventricular systole Lub sound – closing of AV valves before ventricular systole 3. Identify and describe the structure and function or arteries, veins and capillaries Part Structure and Function Arteries Blood vessels that carry blood away from heart + Has smooth muscle and elastic fibres, so when the ventricle contract and blood is pushed into arteries, the walls of arteries stretch to accommodate extra blood. + Elastic recoil keeps blood moving and maintains pressure Vasoconstriction is the contraction of a blood vessel to reduce amount of blood flow. Vasodilation is the increased width of a blood vessel to increase blood flow. Heart → artery → arteriole → capillary Veins Blood vessels that carry blood towards heart Don’t have a muscular wall Can’t change diameter Low blood pressure + Veins have valves to prevent backflow of blood as pressure is low and not constant Capillary → venules → vein → heart Capillaries A microscopic blood vessel that links arterioles and venules. Carry blood to every cell in body + Only 1 layer of cells so substances can easily pass between blood and surrounding cells. 4. Identify the components of blood and describe the structure and function of erythrocytes, leucocytes, thrombocytes and plasma Plasma o Mixture of water with dissolved substances. o Plasma transports components of blood (cells, nutrients, wastes hormones, proteins, antibodies) throughout body. o 55% blood volume. Erythrocytes o Red blood cells transport oxygen from the lungs and remove carbon dioxide from body tissue. o Bi-concave shape and no nucleus, which increases flexibility, but shortens their lifespan to 120 days. o 40-45% blood volume. o Contains haemoglobin: a protein that binds oxygen. Leucocytes o White blood cells protect the body from infections. o