Heart System PDF

Cardiovascular system & Lymphatic system Instructor Dr. Faiza Siddiqui Assistant Professor Dept. of Anatomy  Functions of CVS The CVS is a transport system carrying 1. Oxygen, nutrients etc. to tissues 2. Carries CO2 and other waste products...

Cardiovascular system & Lymphatic system Instructor Dr. Faiza Siddiqui Assistant Professor Dept. of Anatomy  Functions of CVS The CVS is a transport system carrying 1. Oxygen, nutrients etc. to tissues 2. Carries CO2 and other waste products to lungs and kidneys. The CVS consists of, 1. The Heart 2. The blood vessels The Heart LOCATION:- The heart is a pyramid shaped; hollow muscular organ located in the middle mediastinum in the thorax between the lungs. It has a base & an apex. Apex-Directed downward, forward & to the left Formed by the left ventricle Lies at the level of the 5th left intercostal space (3.5"/ 8-9 cm from the midsternal line) APEX  Coverings of the heart The heart is covered by a membrane called Pericardium. This is a double layered membrane having a cavity filled with pericardial fluid in between. Functions: To restrict excessive movements of the heart To serve as a lubricated container in which the different parts of the heart can contract  Fibrous pericardium A cone-shaped bag with its base on the diaphragm and its apex continuous with the of outer coats of the great vessels. Superiorly: it fuses with the tunica adventitia (perivascular connective tissue) of the great blood vessels passing through it, namely: the aorta, the pulmonary trunk, the superior and inferior venae cavae, and the pulmonary veins Inferiorly: the base is attached to the central tendon of the diaphragm by the pericardiacophrenic ligament and to a small muscular area of the diaphragm on the left side. Anteriorly: it is attached to the posterior surface of the sternum by sternopericardial ligaments. These attachments help to retain the heart in its position in the thoracic cavity. The sac also limits cardiac distention. Serous pericardium Closed sac lies within fibrous pericardium Parietal layer lines the inner surface of the fibrous pericardium Visceral layer (epicardium) adheres to the heart and forms its outer covering The slitlike space between the parietal and visceral layers is referred to as the pericardial cavity. Normally, the cavity contains a small amount of tissue fluid (~ 50 mL) the pericardial fluid. The pericardial fluid acts as a lubricant to facilitate (frictionless) movements of the heart. →Pericarditis Clinical anatomy An inflammation of pericardium Clinical presentations: ▪ Continuous central chest pain ▪ Friction between opposing layers of serous pericardium (pericardial friction rub) ▪ Possible pericardial effusion → excessive fluid in the pericardial cavity. ▪ Pericardial effusion can compress the thin-walled atria and interfere with the filling of the heart during diastole and reduces cardiac output. ▪ Such compression of the heart is called cardiac tamponade. ▪ Aspiration of fluid from the pericardial cavity ▪ To relieve cardiac tamponade ▪ Performed with a needle at the left infrasternal angle through the cardiac notch of the left lung. Heart ▪ A muscular organ that pumps blood around the body by circulating it through the circulatory system. ▪ Consists of four chambers Two atria (inflow chambers) Two ventricles (outflow)  Inferior (diaphragmatic) Surfaces Of The Heart The heart rests on the diaphragmatic surface, which consists of the left ventricle and a small portion of the right ventricle. Anterior (sternocostal) - formed This surface faces inferiorly, rests on the mostly by diaphragm, is separated from the base of the Right ventricle, heart by the coronary sinus, and extends from the Part of the right atrium and left ventricle base to the apex of the heart Base (posterior surface) - The base of the heart is quadrilateral and directed posteriorly. It consists of: ▪ Left atrium, ▪ A small portion of the right atrium ▪ Proximal parts of the great veins (superior and inferior venae cavae and the pulmonary veins) Borders of the heart 1. Right - formed by right atrium 2. Left - formed by left auricle and left ventricle. 3. Inferior/lower - right ventricle and a small portion of the left ventricle near the apex. Anterior surface of heart Pulmonary Aorta trunk SVC Left ventricle Right atrium IVC Right ventricle  Image result for heart anatomy chambers and valves Chambers of heart The heart consists of , Right atrium Receiving Left atrium chambers AND Right ventricle Pumping Left ventricle chambers The atria are separated by the interatrial septum and the two ventricles are separated by the interventricular septum  The right atrium receives deoxygenated blood from the body through 3 veins, Right atrium Superior Vena cava (SVC): - Brings blood from the upper part of the body. Inferior Vena cava (IVC) : - Brings blood from the lower part of the body. Coronary sinus : - brings blood from the heart. The right atrium opens into the right ventricle through an opening guarded by tricuspid valve. Image result for sulcus terminalis heart anatomy  Right ventricle Image result for heart anatomy left atrium The right ventricle receives blood from the right atrium via the tricuspid opening. It pumps blood to the lungs through the pulmonary trunk. The opening of the pulmonary artery is guarded by three semilunar valves called the pulmonary valve. Left atrium The left atrium receives the oxygenated blood from the lungs via 4 pulmonary veins. The left atrium sends blood to the left ventricle through the bicuspid opening guarded by the bicuspid or mitral valve. Image result for heart anatomy left atrium Left ventricle The left ventricles receive blood from the left atrium through the bicuspid opening. It pumps blood to the whole body through the aorta. As it pumps blood to all body, so its walls are very thick. The aortic opening is guarded by the semilunar aortic valves.  HEART VALVES The heart consists of 4 valves, 1) Right atrioventricular valve or tricuspid valve. Image result for heart anatomy chambers and valves 2) Left atrioventricular valve or bicuspid valve. 3) The aortic valve 4) The pulmonary valve. Semilunar valves The closure of these valves cause the heart sounds which are heard through a stethoscope. The aortic and pulmonary openings are guarded by 3 semilunar valves each. They prevent the blood from returning to the ventricles. Surface anatomy of the heart valves The tricuspid valve lies behind the right half of the sternum opposite the fourth intercostal space. The mitral valve lies behind the left half of the sternum opposite the fourth costal cartilage. The pulmonary valve lies behind the medial end of the third left costal cartilage and the adjoining part of the sternum. The aortic valve lies behind the left half of the sternum opposite the third intercostal space. Auscultation of the Heart Valves The tricuspid valve is heard just to the left of the lower part of the sternum near the fifth intercostal space. The mitral valve is heard over the apex of the heart in the left fifth intercostal space at the midclavicular line The pulmonary is heard over the medial end of the left second intercostal space The aortic valve is heard over the medial end of the right second intercostal space.  The conducting system and nerve supply of heart: - The heart muscle has the ability of self contracting. The pace of the heart is started and maintained by special cardiac muscle fibers which form the conducting system of the heart. The nerves can increase or decrease the heart rate. Image result for conducting system of heart anatomy Arterial supply of the heart: Coronary Arteries Right coronary artery arises from the anterior Left coronary artery aortic sinus of the arises from the left ascending aorta posterior aortic sinus of the ascending aorta coronary  Venous Drainage Of The Heart Most blood from the heart wall drains into the right the coronary sinus atrium is a continuation of through tributaries of the coronary sinus Heart and Pericardium  clinical application Atherosclerosis If a coronary artery is blocked it causes myocardial infarction, which can cause, Cardiac arrest or heart attack – Death depending upon the extent of damage. Angiography is done to study the blood supply of heart. Angioplasty is done to open a blocked artery. In Cardiac bypass blocked arteries are replaced. Blood vessels Blood vessels are tubelike structures which carry blood. There are three types of blood vessels viz. Arteries:- These are vessels carrying blood away from the heart. They go to all parts of the body and divide and re-divide to form capillaries. Smallest arteries are called arterioles. Capillaries:- Microscopic in structure. They form networks in the tissues and join to form veins. The walls of capillaries are very thin and exchange of oxygen and nutrients occurs through them. Veins:- Veins carry the blood back to the heart. Small veins join to form large veins which enter the heart.Veins have valves to prevent back flow of blood. Smallest veins are called the venules. Blood circulation in the body The blood in the body circulates in two circuits, Pulmonary circulation between lungs and heart. Systemic circulation between the heart and the rest of the body  Blood circulation Arteries of the body Arteries carry blood away from the heart. Pulmonary artery carries blood to the lungs. Aorta is the largest artery of the body arising from the left ventricle. It has following parts, 1) Ascending aorta 2) Arch of aorta 3) Descending aorta which has, a) thoracic part b) abdominal part Ascending thoracic aorta ▪ Origin : it begins at the base of left ventricle and lies behind the the right half of the sternum at the level of sternal angle, where it becomes continuous as arch of aorta. ▪ At root, it has bulges known as the sinuses of the aorta. Branches; 1.The right coronary artery. 2.The left coronary artery. 29 Arch of the aorta: It lies behind the manubrium sterni and arches upward , backward and to the left in front of the trachea. It then passes downward to the left of the trachea and at the level of the sternal angle to continue as descending thoracic aorta. 30  31 Descending thoracic aorta ▪ It lies in the posterior mediastinum and begins as a continuation of the arch of aorta at the level of lower border of the 4th thoracic vertebra on its left side(i.e. opposite the sternal angle). ▪ At the level of the 12th vertebra, it passes behind diaphragm(through aortic opening). Branches ▪ Posterior intercostal arteries ▪ Subcostal arteries ▪ Pericardial ,esophageal & bronchial arteries. Clinical notes: Aneurysm and coarctation of the aorta. Pulmonary trunk ▪ Conveys deoxygenated blood from rt.ventricle of heart to lungs. ▪ Runs upwards backwards to the left. ▪ About 2 inches long. ▪ Terminates into right. & left pulmonary arteries. 32  Arteries of Upper Limb: - The Subclavian artery supplies the upper limb. The name is changed according to place, 1) Axillary A in armpit 2) Brachial A in arm this divides into, 3) Radial A 4) Ulnar A © 2018 Pearson Education, Inc Clinical anatomy 1) Blood pressure is measured from the brachial A. 2) Pulse is taken by pressing the radial artery at the lateral side of the wrist. 3) Intravenous injections -median cubital vein  Arteries Of Lower Limb: - The external iliac Artery continues into the thigh as follows, 1. Femoral A in front of thigh. 2. Popliteal A at the back of knee 3. Anterior tibial A in front leg 4. Posterior tibial A in back of leg. Clinical points: - Femoral A pulse can be felt in the front of thigh. Arteries of pelvis The internal iliac artery supplies the pelvic organs, walls and muscles. Veins of the body The veins of the upper half of the body all join to form the Superior vena cava (SVC) The lower veins of the body all drain into Inferior vena cava (IVC) Veins opening in Superior vena cava:- Veins of the head and neck Veins of the upper limb Thoracic veins © 2018 Pearson Education, Inc Veins of the upper limb all join to form the Veins of upper limb Subclavian veins. which enter the SVC. Superficial veins are seen on the dorsum of the hand, and one is present in front of the elbow called the Median cubital vein Clinical points; - Intravenous (IV) injections are given in the median cubital vein. Blood can also be drawn from this vein. The injections can be given in the veins on the dorsum of the hand. Tributaries of /Veins draining into the inferior vena cava Veins of the abdomen Veins of the pelvis Veins of lower limb. VEINS OF ABDOMEN:- These are renal veins, hepatic veins etc. all open into IVC. In the abdomen there is a special vein called portal vein, which drains the digestive tract and then enters the liver. VEINS OF THE PELVIS:- These all form the Internal iliac vein , which joins the external iliac vein to form the common iliac vein. The two common iliac veins join to form the Inferior vena cava. Portal circulation Veins carrying the nutrition rich blood from the GIT is carried into the portal vein. This goes and breaks up into capillaries again in the liver. From the liver this blood goes to the IVC THANK YOU Lymphatic System The blood in capillaries passes out some fluid to the tissues called the tissue fluid/lymph. This fluid either enters the veins or is carried by another pathway, the Lymphatic system The lymphatic system consists of 1) Lymphatic vessels-- through which some of the tissue fluid - Lymph passes before entering large veins. 2) Lymphatic or lymphoid organs---- which are, Lymph node Thymus Tonsil Spleen  Thoracic duct Thoracic duct:- starts in the abdomen and passes through the posterior part of thorax to the neck where it opens into subclavian vein of left side. It drains the left side of the upper half of the body and all the lower part i.e. Both lower limbs, whole pelvis and abdomen and the left side of thorax, left upper limb and left side of head and neck Right lymphatic duct:- is smaller and drains the right side of thorax, right upper limb and right side of head and neck. It opens into right subclavian vein. The tissue fluid flowing through these vessels is called-----Lymph.. Lymph Nodes Clinical anatomy Lymph nodes enlarge in infections and cancer. The enlargement is in the area drained by those lymph nodes Tonsils Tonsils are lymphoid organs present in the oropharynx. They prevent infectious agents from entering the repiratory and digestive tracts. Enlargement of the tonsils due to infection is called as Tonsillitis.  SPLEEN Location: ▪ The spleen is reddish and is the largest single mass of lymphoid tissue in the body. ▪ It is oval shaped and has a notched anterior border. ▪ It lies just beneath the left dome of the diaphragm close to the 9th, 10th, and 11th ribs. ▪ Normally it cannot be palpated per abdomen. ▪ Filters blood. It destroys the old red cells of the blood. ▪ It enlarges in acute infection ▪ Cancer cells rarely spread to the spleen because it lacks afferent vessels 10/9/2024 51 Thymus It is a soft gland present in the thorax behind the sternum. It is large in infants and children. After puberty decreases in size. It produces lymphocytes and gives immunity to children THANK YOU