Introduction to Cardiovascular System PDF, Fall 2024

SGD 2 Medicine and Surgery Program GIT BMS(Pharynx 111 & esophagus)Fall 2024 Lecture No: 6 Title: Introduction to cardiovascular system Prof. Dr. Eman Habib Assist. P...

SGD 2 Medicine and Surgery Program GIT BMS(Pharynx 111 & esophagus)Fall 2024 Lecture No: 6 Title: Introduction to cardiovascular system Prof. Dr. Eman Habib Assist. Prof. Dr. Rania Galhom At the end of this lecture, the students should be able to: ❑ Describe the structures forming the cardiovascular system ❑ List the chambers of the heart ❑ Differentiate between pulmonary, systemic & portal circulations ❑ Enumerate the types of blood vessels and differentiate between them ❑ Describe the different types of connections between arteries & veins Faculty of Medicine 3 THE CARDIOVASCULAR SYSTEM Faculty of Medicine (CVS) is formed of : 1. The heart 2. The blood vessels Arteries Veins 3- Circulating blood Faculty of Medici ne 4  The Heart ❑ Definition: it is a pump which propels the blood into the blood vessels. ❑ Location: It is present in the thoracic cavity between the 2 lungs (behind sternum and costal cartilages from2-6) Right Left lung lung Heart  External features of the heart The heart is formed of 4 chambers 2 Atria 2 Ventricles ❑ Right atrium ❑ Right ventricle ❑ Left atrium ❑Left ventricle left atrium right atrium left ventricle right ventricle  Heart, anterior view LA RA Left atrium Right LV atrium Left RV ventricle Right ventricle  Right half Contains Impure (deoxygenated) blood The right and left halves of heart are completely separated by certain septa (interatrial & interventricular) to prevent Left half contains mixing of oxygenated and deoxygenated Pure (oxygenated)blood blood  The Heart cont… The big blood vessels connected to the heart veins arteries Superior vena cava Aorta 4 pulmonary veins Pulmonary artery Inferior vena cava ❑ The heart is a cone-shaped. ❑ It has apex. The Heart I. Apex: It is directed downwards, forwards and to the left. It is formed by the left ventricle only. Surface anatomy of the Apex of The Heart The apex of the heart is located at the left 5th intercostal space, 9 cm from the middle line, just below the left nipple Apex of the Heart  *1 *2 * 3 * 4 * 5 9cm Apex of the heart  The Heart 4 borders: Upper border: formed by the 2 atria (mainly the left). Lower border: formed by the right ventricle and apical part of left ventricle. Right border: formed by the right atrium. Left border: formed by the left ventricle.  The Heart Surfaces of the heart  Surfaces of the heart 1. Sterno-costal surface: It is formed of atrial and ventricular parts a. Atrial part: formed mainly by the right atrium. b. Ventricular part: formed by right ventricle (right ⅔) and left ventricle (left ⅓).  Surfaces of the heart 2. Diaphragmatic surface: Rests on the diaphragm. It is formed of right ventricle (right ⅓) and left ventricle (left ⅔).  The Heart cont… FUNCTIONS OF THE 4 chambers 2 Atria 2 Ventricles ▪ Right atrium : ▪ Right ventricle collects venous blood pumps blood to lungs from body. ▪ Left ventricle Pumps blood to the whole ▪Left atrium body. receives oxygenated blood from lungs. The wall of the left ventricle is the thickest Difference in thickness of ventricular wall 3 1 Right Ventricle Left Ventricle  Thevalves Heart Heart cont… They permit the blood to pass in one direction only. (prevent reflux or backflow) valves between atria& ventricles: Mitral valve : between left atrium & left ventricle Tricuspid valve: between Right atrium & Right ventricle Aortic and pulmonary valves: guard the aorta and pulmonary trunk  The Heart cont… ❑ Direction of blood inside the heart: Right atrium Left atrium Left ventricle Right ventricle ❑ Direction of blood inside the heart: Circulation of blood  Types of Circulations I- Systemic II- Pulmonary circulation circulation ❑ Left ventricle ❑ right ventricle Aorta pulmonary Body artery gaseous lungs exchange gaseous superior & exchange inferior Vena pulmonary cava veins Right atrium left atrium Pulmonaray Circulation Systemic Circulation  Types of Circulations III- Portal Circulation: Venous blood from digestive tract into portal vein enters the liver  THE BLOOD VESSELS Arteries Veins Carry blood away Carry blood towards from the heart. the heart. Carry oxygenated bl. Carry deoxygenated bl. (except Pulmonary A.) (except Pulmonary V.) Collect from tributaries Divide into branches (venules) (arterioles). Thick-walled Thin-walled narrow lumen wide lumen.  Artery Vein The 1 Carries the blood from the heart to Carries blood from tissues to heart differences tissues. between an artery and a 2 It transmits oxygenated blood It transmits deoxygenated blood vein [except for the pulmonary artery] [except for the pulmonary veins] Its wall is thick as it contains Its wall is thin. a thick muscular layer 3 Its wall contains an elastic layer so Its wall does not contain an elastic that it does not collapse when cut layer so that it does collapse when cut. 4 It is not provided with valves It is provided with valves Valve in a vein Valves are present in veins to prevent flowback of the blood Varicose veins back flow of blood into the superficial veins. This results in an increased intra-luminal pressure, which the veins cannot withstand, causing them to become dilated and tortuous. This condition is known as varicose veins. Image result for varicose veins 33 Venipuncture is the practice of obtaining intravenous access. This is usually for the purpose of providing intravenous therapy (e.g. fluids, medications) or for obtaining a blood sample. 34  Wavy arteries Arteries which supply movable organ Facial artery Splenic artery Arteries which supply expansile organs Uterine artery Lingual artery splenic artery Facial artery Lingual artery  THE BLOOD VESSELS cont.. Arterial Anastomosis It is the presence of multiple branches joining 2 arteries. It allows a collateral circulation in case of obstruction of one artery It is present mainly around joints. Arteries which do not anastomose are called end arteries.  THE BLOOD VESSELS cont.. End Arteries End arteries: arteries that have ❑ no anastomosis ❑insufficient anastomosis. If an end artery is occluded the tissues supplied by it would suffer infarction.  THE BLOOD VESSELS cont.. End Arteries Anatomical end arteries functional end arteries no connection exists at all anastomosis exists between between the arteries. arteries but If this artery is obstructed, it is not sufficient to compensate damage of the area occur the obstructed artery e.g. coronary arteries of heart. e.g. central retinal artery. THE BLOOD VESSELS cont.. Connections between arteries and veins  Connections between Arteries and Veins 1- Capillaries 2- Arterio-venous shunt 3- Sinusoids Minute vessels , thin walls Direct connections between regular diameter small arterioles & venules. Irregular wide thin Present in all parts of the are numerous in lips & nose walled spaces body surrounded by sphincters to Present in many site of exchange between control blood to regulate body sites like liver, blood &tissues temperature spleen Time For QUIZ 1- Which of the following guards the opening of right atrium into right ventricle? a) mitral valve b) tricuspid valve c) bicuspid valve d) aortic semilunar valve 2- Which of the following has the thickest wall? a) Right ventricle b) Left ventricle c) Right atrium d) Left atrium 3- Which of the following is considered end artery? A. Central retinal B. Brachial C. Radial D. Ulnar 4- which of the following describe the circulation between the liver and the digestive system? A. Pulmonary circulation B. Systemic circulation C. Portal circulation 5- A 46-year-old male patient with high blood pressure was examined in the emergency department, and his physician found a leakage of blood from the blood vessel that normally carries richly oxygenated blood. Which of the following vessels would most likely be damaged? A- Superior vena cava B -Pulmonary arteries C- Pulmonary veins D- Portal vein E-Coronary sinus In the previous x- ray there is enlargement in the chambers of the heart that form its right and left borders (yellow and red lines, respectively). Mention these chambers. Cardiomegaly = Enlarged heart References: 1 Snell's clinical anatomy by regions (2019): 10th Edition 2-Clinically oriented anatomy, K.L. Moore & A. F. Dalley 3 -Grey's anatomy for students, Drake et. al. 4 -Sadler TW. Langman’s Medical Embryology, 10th edition. Lippin, Williams and Wikins