Cardiovascular System Part-1 PDF (ANAT 211, 212, 213, Term 2, 2023-24)

Cardiovascular System Part-1 Anatomy Course ANAT 211, 212 and 213 Term 2, 2023-24 Basic Sciences Department, COSHP, KSAU-HS, KSA Cardiovascular System Part-1 By the end of this session the student should be able to: List the main components of the cardiovascular system. Describe the location and pos...

Cardiovascular System Part-1 Anatomy Course ANAT 211, 212 and 213 Term 2, 2023-24 Basic Sciences Department, COSHP, KSAU-HS, KSA Cardiovascular System Part-1 By the end of this session the student should be able to: List the main components of the cardiovascular system. Describe the location and position of heart. Describe briefly, the pericardium and pericardial cavity. Describe the external features of the heart in terms of surfaces, borders, chambers and grooves. Describe blood supply of the heart in terms of right and left coronary arteries, right marginal arteries, posterior and anterior interventricular arteries and circumflex arteries with their area of supply. Describe the main veins of the heart and coronary sinus. Define components of the heart wall epicardium, myocardium and endocardium. Components of the Cardiovascular System Heart Arteries Veins Capillaries Lymphatics Heart: Four chambered muscular organ Pumps blood to all organs/parts of the body Receives blood back from the body Cardiac Chambers The heart, functionally, consists of two pumps separated by a partition 1-The right pump receives deoxygenated blood from the body and sends it to the lungs 2-The left pump receives oxygenated blood from the lungs and sends it to the body Each pump consists of: Atrium: Receiving chamber Ventricle: Pumping chamber The four chambers of the heart are separated by Inter-atrial Interventricular septa Atrioventricular valves Surface Anatomy of Heart The upper margin of the heart the 3rd costal cartilage on the right side of the sternum and the 2nd intercostal space on the left side of the sternum The lower margin of the heart Extends from the sternal end of the right 6th costal cartilage to the apex in the left 5th intercostal space near the midclavicular line Right margin of the heart Extends from the right 3rd costal cartilage to the 6th costal cartilage Left margin of the heart Extends from the left 2nd left intercostal space to the apex located on the midclavicular line in the 5th left intercostal space Location of the Heart The heart lies within the pericardium in the middle mediastinum, more towards the left side It is: Posterior to sternum (2nd-6th ribs) Medial to lungs Anterior to vertebral column (T5-T8 vertebrae) Apex at 5th left intercostal space Base lies beneath 2nd rib Rests upon diaphragm Pericardium Pericardium: encloses the heart and the roots of the great vessels and is made up of TWO sacs intimately connected with one another 1-Fibrous pericardium is an outer tough fibrous sac that covers the heart and fuses with the great vessels (aorta, superior vena cava, pulmonary (trunk) artery). 2-Serous pericardium is an inner closed serous sac and divided into: Parietal pericardium lines the fibrous pericardium Visceral pericardium is closely applied to the heart. It is also called the epicardium Fibrous pericardium Diaphragm Pericardial Cavity Pericardial cavity is a slit-like space between the two layers of serous pericardium it contains the serous pericardial fluid Surfaces of the Heart The heart is pyramid shaped and has an apex, a base and three surfaces The sternocostal/anterior surface is formed mainly by the right ventricle and right atrium and some of the left ventricle. The right ventricle is separated from the left ventricle by the anterior interventricular groove Surfaces of the Heart The diaphragmatic/inferior surface is formed mainly by the right and left ventricles, separated by the posterior interventricular groove. The inferior surface of the right atrium into which the Inferior vena cava opens also forms part of the inferior surface. This surface rests on the diaphragm Surfaces of the Heart The posterior surface/base is formed mainly by the left atrium, four pulmonary veins open into it A small portion of the right atrium; and the proximal parts of the great veins (superior and inferior venae cavae) also contribute. The base of the heart lies opposite the apex The apex of the heart is directed downward, forward and to the left. It is formed by left ventricle and lies deep to the left 5th intercostal space, 8-9cm from the midsternal line Borders of the Heart The right border is formed by the right atrium The left border is formed by the left auricle and the left ventricle The inferior border is formed mainly by the right ventricle, also by the right atrium and the left ventricle at the apex These borders are important to recognize when examining a heart radiograph Sulci/Grooves of the Heart The coronary sulcus separates the atria from the ventricles It contains coronary sinus, small cardiac vein, right coronary artery and circumflex branch of the left coronary artery The posterior interventricular sulcus is on the diaphragmatic surface of the heart It contains posterior interventricular artery and middle cardiac vein The anterior interventricular sulcus is on the anterior surface of the heart It contains anterior interventricular artery and great cardiac vein Both interventricular sulci/grooves mark the attachment of the interventricular septum on the inside. Arterial Supply of the Heart Coronary arteries are principal arteries that deliver oxygenated blood to myocardium. These are right coronary artery and left coronary artery, branches from the aorta Right coronary artery originates from right aortic sinus of the ascending aorta. It descends down and continues posteriorly in the coronary sulcus to anastomose with the left coronary artery in the atrioventricular groove/coronary sulcus The right coronary artery gives: Atrial branches The nodal branch to the SA node Right marginal branch Posterior interventricular branch that runs in the posterior interventricular sulcus Septal branches Arterial Supply of the Heart The left coronary artery originates from the left aortic sinus of the ascending aorta. It passes forwards between the pulmonary trunk and the left auricle to enter in the coronary sulcus. It divides into two terminal branches: 1-The anterior interventricular branch (left anterior descending artery-LAD) descends towards the apex of heart in the anterior interventricular sulcus. It supplies the anterior portions of both ventricles and the interventricular septum 2-The circumflex branch runs to the left and circles posteriorly in the coronary sulcus to the diaphragmatic surface of the heart, where it anastomoses with the right coronary artery. It gives off the left marginal artery and atrial branches Cardiac Veins Cardiac veins: The veins drain blood from myocardium into the coronary sinus that empties into the right atrium. The main cardiac veins are: Great cardiac vein lies in the anterior interventricular sulcus. In the coronary sulcus, it enlarges to form the coronary sinus. It drains the anterior surface Middle cardiac vein: from the apex, it ascends in the posterior interventricular sulcus to join the coronary sinus. It drains the inferior surface Small cardiac vein runs in the coronary sulcus and drains the right side of the heart The posterior cardiac vein lies on the posterior surface of the left ventricle The anterior and smallest cardiac veins drain directly into the heart chambers. Heart Wall The walls of the heart are composed of: 1-Epicardium: Outer connective tissue layer of serous pericardium 2-Myocardium: Middle muscular layer made up of the cardiac muscles arranged in whorls like turban 3-Endocardium: Inner endothelial layer facing to the chambers of the heart Coronary blood vessels run between epicardium and myocardium