Cardiovascular System PDF

‫بسم هللا الرحمن الرحيم‬ Cardiovascular system  The cardiovascular system is comprised of the heart, veins, capillaries, arteries and blood , which work together to supply the body tissues with nourishment and collect waste materials. Functions of the circulatory system...

‫بسم هللا الرحمن الرحيم‬ Cardiovascular system  The cardiovascular system is comprised of the heart, veins, capillaries, arteries and blood , which work together to supply the body tissues with nourishment and collect waste materials. Functions of the circulatory system: 1-Distribute nutrients, 2- Transport and exchange oxygen and carbon dioxide, 3- Remove waste materials 4- Distribute secretions of endocrine glands, 5- Prevent excessive bleeding 6- Prevent infection, and 7- Regulate body temperature  Heart Anatomy The heart is a funnel-shaped, hollow, muscular organ that is responsible for pumping blood to all parts of the body.  Heart Anatomy Approximately the size of your fist Location – The heart is located near the center of the thoracic cavity between the lungs – is contained in the pericardial sac. 5  PERICARDIUM CONFINES HEART TO THE MEDIASTINUM CONSISTS OF TWO PARTS:THE FIBROUS AND SEROUS.  Gross Anatomy of Heart: Frontal Section Figure 18.4e 7 Chapter 18, Cardiovascular System  Parts of the heart The heart is divided into a right and left side and each side is divided into an atrium and ventricle. Therefore, the heart is said to have four chambers (right atrium, right ventricle, left atrium, and left ventricle).  Atria are the receiving chambers of the heart Atria of the Each atrium has a Heart protruding auricle Pectinate muscles mark atrial walls 9 Chapter 18, Cardiovascular System  Rt. Atrium Blood enters right atria from superior and inferior venae cavae and coronary sinus  Blood enters left atria from pulmonary veins  Ventricles of the Heart Ventricles are the discharging chambers of the heart Papillary muscles and trabeculae carneae muscles mark ventricular walls 12 Chapter 18, Cardiovascular System  Rt ventricle Right ventricle pumps blood into the pulmonary trunk  Lt ventricle Left ventricle pumps blood into the aorta  Thickness of Cardiac Walls Myocardium of left ventricle is much thicker than the right. 15 Chapter 18, Cardiovascular System  Heart Valves Heart valves ensure unidirectional blood flow through the heart Atrioventricular (AV) valves lie between the atria and the ventricles – AV valves prevent backflow into the atria when ventricles contract Chordae tendineae anchor AV valves to papillary muscles 16 Chapter 18, Cardiovascular System  Valves three tricuspid (cusp means flap) one bicuspid “Tricuspid” valve – RA to RV Pulmonary or pulmonic valve – RV to pulmonary trunk (branches R and L) Mitral valve (the bicuspid one) – LA to LV Aortic valve – LV to aorta 17  Electrical conduction system: specialized cardiac muscle cells that carry impulses throughout the heart musculature, signaling the chambers to contract in the proper sequence (Explanation in next slides) 18 Conduction system SA node (sinoatrial) – It is the pace-maker of the heart. It is present in the wall of right atrium below opening of S.V.C Impulse from SA to atria Impulse also to AV node via internodal pathway AV node – In interatrial septum 19  Atrioventricular node (A.V.N): It is present in lower part of interatrial septum.  Atrioventricular bundle: It originates from A.V. Node and passes in the upper part of interventricular septum.  Bundle branches: They are right and left branches of the A.V. Bundle, that pass along the right and left sides of the interventricular septum.  Purkinje fibers: They are fibers that pass in the walls of ventricles from the ends of the bundle branches. Blood supply of the Heart  Arterial supply of Heart ▪ Right coronary artery (supply mainly Rt atrium and most of Rt ventricle and SAN) ▪ Left coronary artery (supply mainly Lt atrium and Lt ventricle) Right Coronary Artery Left Coronary Artery Types of blood circulation: 1- Systemic Circulation 2- Pulmonary Circulation 3- Portal circulation: ARTERY: Definition: is a blood vessel that carries blood rich in oxygen, away from the heart to peripheral organs except for pulmonary arteries Types: larger conducting arteries smaller distributing arteries the smallest arteries, VEINS : are blood vessels that carry blood toward the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart. Capillaries: : A capillary is the smallest blood vessel. ❖ It does not have the muscular/elastic tissue of other blood vessels. ❖ they connect arteries and venules, ❖ enable the moving of water, oxygen, carbon dioxide, as well as many other nutrients and waste chemicals between blood and surrounding tissues