L7 CVS Anatomy of the Cardiovascular System PDF

Anatomy of the Cardiovascular system Department of human Anatomy and Embryology Faculty of Medicine Mansoura National University, Egypt  Intended Learning Outcomes (ILOs) 1. Enumerate the chambers of the heart 2. Identify the blood supply of the...

Anatomy of the Cardiovascular system Department of human Anatomy and Embryology Faculty of Medicine Mansoura National University, Egypt  Intended Learning Outcomes (ILOs) 1. Enumerate the chambers of the heart 2. Identify the blood supply of the heart 3. Enumerate the types of blood vessels  Agenda 1. What are the different types of blood vessels? 2. What are the chambers of the heart? 3. What is the blood supply of the heart?  Cardiovascular system It consists of the heart & blood vessels. The Heart : It is a hollow muscular organ which pumps blood into the blood vessels. Shape: ❖ The heart is conical in shape. ❖ It has apex, base, 4 surfaces and 4 borders. ❖ Base of the heart is formed by both atria while its apex is formed by the left ventricle. Position: ❖ The heart lies obliquely in the middle part of thoracic cavity with its base directed posteriorly and its apex directed anteriorly and to the left. ❖ It is enclosed by a fibro- serous sac called pericardium  Chambers of the heart ❖The heart is formed of 4 chambers; two atria and two ventricles. Blood content Blood enters it through Blood leaves it through Right atrium None oxygenated Superior and inferior Tricuspid orifice to venae cava the right ventricle Right None oxygenated Tricuspid orifice Pulmonary trunk to ventricle both lungs Left atrium Oxygenated from 4 Pulmonary veins ( 2 Mitral orifice to the the lungs from each lung ) left ventricle Left ventricle Oxygenated Mitral orifice Aorta to the body  Valves of the heart ❖The heart has four valves; two atrioventricular (mitral & tricuspid) and two semilunar valves (aortic & pulmonary). Site Number of cusps Time of closure Mitral valve Between the left Two During ventricular atrium and left systole ventricle Tricuspid valve Between the right Three During ventricular atrium and right systole ventricle Aortic valve Between the left Three During ventricular ventricle and aorta diastole Pulmonary valve Between the right Three During ventricular ventricle and diastole pulmonary trunk  Quiz Mitral valve is located between …? A) right atrium and right ventricle B) left atrium and left ventricle C) left ventricle and aorta D) right ventricle and pulmonary trunk E) right atrium and left ventricle.  Blood supply of the heart ❖ Arterial supply: the heart is supplied by 2 coronary arteries (right and left) which arise from the ascending aorta. ❖ Venous drainage: the heart is drained by 3 cardiac veins (great, middle and small) which drain in the coronary sinus. Then, the coronary sinus ends in the right atrium  Quiz Where does the coronary sinus end ? A) right atrium B) left atrium C) left atrium D)Left ventricle  Types of blood vessels There are three types of blood vessels: 1. Arteries. 2. Veins. 3. Capillaries.  Arteries ❖ Arteries transport blood away from the heart to different body tissues. ❖ They don’t have valves. ❖ All arteries carry oxygenated blood except the pulmonary arteries. ❖ They divide into branches and the small arteries are called arterioles. ❖ Union between arteries is known as arterial anastomosis. ❖ End arteries don’t have anastomosis (e.g.; arteries of the brain, kidney, spleen and retina). So, obstruction of end artery leads to ischemia and necrosis. ❖ Wavy arteries run in a tortuous course to supply mobile or expansile organ (e.g.; facial, lingual, splenic and uterine arteries).  Quiz One of the following arteries has a tortuous course: A) axillary artery B) superior mesenteric artery C) uterine artery D) ovarian artery E) central artery of retina  Veins ❖ Veins transport blood towards the heart. ❖ Many of them have valves. ❖ All veins carry non-oxygenated blood except pulmonary veins. ❖ Veins have tributaries and the small veins are known as venules.  capillaries ❖ Capillaries are minute vessels in the form of a network connecting the arterioles with the venules. ❖ Their walls are very thin to allow gas and fluid exchange between the blood and the tissue.