Cardiovascular System PDF

Active learning ▪ Why do some students learn better than others? ▪ What do they do? - Take notes while listening - Read your notes and add points – recall 1 - Read again in a weeks' time – recall 2 - Make a flash card/notes - Look at it in a month's time CARDIOVASCULAR SYSTEM (CVS) Devi L...

Active learning ▪ Why do some students learn better than others? ▪ What do they do? - Take notes while listening - Read your notes and add points – recall 1 - Read again in a weeks' time – recall 2 - Make a flash card/notes - Look at it in a month's time CARDIOVASCULAR SYSTEM (CVS) Devi Learning Objectives ▪ State the size, form and location of the heart ▪ Explain the major function of the CVS ▪ Understand the components of the CVS ▪ Describe the structure of the heart ▪ Brief the importance of the heart ▪ Explain the circulatory system ▪ Explain the cardiac cycle ▪ Understand ECG  Size, form and location of the heart ▪ Size: one's own closed fist. ▪ Shape: blunt cone ▪ Location: Thoracic cavity between the lungs in a space within the mediastinum called the Pericardial cavity ▪ The blunt, rounded point of the cone is the apex, and the larger, flat portion at the opposite end of the cone is the base Location of the heart Major Function of the CVS The cardiovascular system consists of the heart, blood vessels and blood. Its primary function is to transport nutrients and oxygen-rich blood to all parts of the body and to carry deoxygenated blood back to the lungs The Heart The heart Contracts forcefully to pump blood through the vessels of the body. The heart has actually two pumps in one. One propels blood through the pulmonary circulation (to the lungs where the blood releases carbon dioxide and receives oxygen) Other propels blood through the systemic circulation ( to all remaining tissues of the body) Blood vessels A closed system of blood vessels: These vessels include: Arteries: Vessels that carry blood away from the heart. Veins: Vessels that bring blood back to the heart. Capillaries: Tiny vessels that branch off from arteries to deliver blood to all body tissues Heart wall (Heart layers) 3 Layers of heart Composed of three layers 1. Epicardium( visceral pericardium)- thin serous membrane comprising the smooth outer surface of the heart. 2. Myocardium – thick middle layer of the heart, composed of cardiac muscle cells and is responsible for contraction 3. Endocardium – Smooth inner surface, allows blood to move easily through the heart. The heart valves are formed by a fold of the endocardium, making double layer of endocardium with connective tissue in between Structure of the heart Sternocostal surface of the heart  The importance of the heart The heart pumps blood through closed vessels to every tissue within the body. The blood itself then delivers nutrients and oxygen to all cells in the body. Without blood, the cells and tissues would not function at their total capacity and would begin to malfunction and die. Circulatory system Pulmonary circulatory system: This circulatory system moves blood between the heart and lungs. It is where oxygen enters the blood and carbon dioxide leaves the blood Systemic circulatory system : This is the main blood circulatory system that transports blood to the organs, tissues, and cells throughout the body. Circulatory system  Pulmonary circulation Right Tricuspid Transports atrium valve opens deoxygenated (poor Oxygen) blood to the Right Deoxygenat right and the left ventricle ed blood lungs Right Pulmona and ry artery left lungs MITRAL Systemic VALVE Left Circulation atrium Carries oxygenated blood Upper throughout the Left System and body. It carries lower ventricl ic parts of oxygen and e circuit the nutrients to the body cells and picks up carbon dioxide AORTIC and waste valve Aorta products.  Valves of the heart Tricuspid valve: This valve has three leaflets. They allow blood to flow from the right atrium to the right ventricle. They also prevent blood from flowing backwards from the right ventricle to the right atrium. Mitral valve (Bicuspid Valve): This valve has two leaflets. They allow blood to flow from the lungs into the left atrium. And they prevent backward flow from the left ventricle to the left atrium.  Valves of the heart Pulmonary valve: This valve also has three leaflets. They allow blood to pump from the right ventricle to the pulmonary artery. This artery leads to the lungs, where the blood picks up oxygen. The pulmonary valve prevents blood from going backwards from the pulmonary artery to the right ventricle. Aortic valve: This valve has three leaflets. They open to let blood flow from your heart’s left ventricle to the aorta. The aorta is the largest blood vessel in your body. It brings oxygenated blood from your heart to the rest of your body. The aortic valve prevents backward flow from the aorta into the left ventricle.  Cardiac Cycle Two phases Systolic phase- Ventricles contract and eject blood. It begins when the mitral or tricuspid valve closes and ends when the aortic or pulmonary valve closes. The pressure inside the ventricles becomes greater than the pressure inside adjacent blood vessels, thereby forcing the blood from the ventricles to the vessels Diastolic phase- Ventricles fill with blood. It begins when the aortic or pulmonary valve closes and ends when the mitral or tricuspid valve closes During diastole, blood vessels return blood to the heart in preparation for the next contraction of the ventricles.. Electrical activity of the heart How it all comes together. Electrical pathway of the heart ▪ The heart has an inbuilt electric circuit that gives the heart the energy to pump blood to the various organs of the body. The Sinoatrial Node (also called the SA Node or the Pacemaker) is where the electrical impulse starts and it continues to the Atrioventricular Node (AV Node) and to the rest heart in a set pattern. Due to the electrical pulses, the heart muscles squeeze and relax in an organized manner causing the blood to keep moving throughout the body. ▪ Electric Pathway: SA Node → AV Node → Bundle of His → Purkinje Fibers(Ventricle contraction) Normal sinus rhythm Relationship between Ecg and Cardiac cycle stages VEVOX 1-5 6. When do you hear S1? A) Tricuspid and mitral valve closes B) Tricuspid and pulmonary valve closes C) Pulmonary valve and aortic valve closes D) Mitral and aortic valve opens 7. Blood enters in pulmonary artery and aorta during A) Atrial systole B) Ventricular diastole C) Ventricular systole D) Atrial diastole 8. Veins have unidirectional valves that prevent blood from flowing backwards A) True B) False 8. What does P wave mean? A) Atrial contraction B) Ventricular Contraction c) Atrial relaxation D) None of the above 9) What is systole? A) Atrial contraction B) Pulmonary contraction C) Ventricular contraction D) Aortic Contraction 10)Blood pressure is directly proportional to blood volume? A) True B) False  Brain feed Anterior – Facing forward or positioned front. Posterior – positioned at or towards the back Anteroposterior (AP)– relating to or directed towards both front and back Lateral- relating to the sides Superior – top part Inferior – lower part Apex - The apex of the heart is the lowest superficial part of the heart. It is directed downward, forward, and to the left  Reference ▪ Isık, G. Ç., Şafak, T., Tandoğan, M., & Çevik, Y. (2020). Effectiveness of the CRISP method on the primary cardiac arrhythmia interpretation accuracy of nurses. The Journal of Continuing Education in Nursing, 51(12), 574-580. https://doi.org/10.3928/00220124-20201113-08 ▪ Jarvis S (2021) Electrocardiogram 2: interpretation and signs of heart disease. Nursing Times [online]; 117: 7, 51-55. ▪ Resuscitation Council UK (2021) 2021 Resuscitation Guidelines. RCU ▪ Jarvis S, Saman S (2018) Cardiac system 1: anatomy and physiology. Nursing Times [online]; 114: 2, 34-37..