Cardiovascular System PDF

Cardiovascular system Dr. Aswathy Sarath ❯ Cardiovascular system deals with heart and its blood vessels heart ❯ Heart is a muscular organ about the size of a fist,located just behind and slightly left of the breast bone(sternum) ❯ Normal blood volume: 5-6 l ❯ Normal hea...

Cardiovascular system Dr. Aswathy Sarath ❯ Cardiovascular system deals with heart and its blood vessels heart ❯ Heart is a muscular organ about the size of a fist,located just behind and slightly left of the breast bone(sternum) ❯ Normal blood volume: 5-6 l ❯ Normal heart rate: 60-100 beats/min ❯ Weight: females(250g) males(300g) ❯ Sthethoscope is the device for auscultation ❯ Heart produces a hormone called ANF(atrial natri uretic factor) which controls the sodium level in the body Chambers of heart ❯ 4 chambers: ❯ Atrium-upper 2 chambers ❯ Ventricles-lower 2 chambers  septum ❯ Septum of heart is the dividing wall between the right and left sides of the heart ❯ Interatrial is between 2 atrias (atrial septum) ❯ Interventricular is between 2 ventricles(ventricular septum) ❯ Atriovenricular is between atria and ventricles( atrioventricular septum) Layers of heart ❖ Endocardium- smooth muscle layer in the innermost layer ❖ Myocardium- middle muscular layer and the thickest layer ❖ Pericardium- layer surrounding the heart Viscreal pericardium (epicardium) Parietal pericardium Pericardial fluid is between viscreal pericardium and parietal pericardium which avoides the friction between the layers Major blood vessels of heart ❯ Superior and inferior venacava ❯ Aorta ❯ Pulmonary artery ❯ Pulmonary vein ❯ Coronary artery Valves of heart ❯ Tricuspid valve- open b/w right atrium and right ventricle ❯ Bicuspid / mitral valve- opening b/w left atrium and left ventricle ❯ Pulmonary valve- opening in pulmonary artery ❯ Aortic valve- valve of aorta ❯ Atrioventricular valve(av)- tricuspid and bicuspid valve ❯ Semilunar valve- pulmonary and aortic valve  Circulation of heart ❯ Right ventricle pumps blood to the lungs(pulmonary circulation) for oxygenation and the left ventricle pumps oxygenated blood to the entire body(sytemic circulation). ❯ Deoxygenated blood from the body returns to the right atrium by two large veins, superior venacava which collects blood from upper body and inferior venacava which collects blood from lower body. ❯ From the right atrium,blood passes through the tricuspid valve to the right ventricle. ❯ When the heart contract,blood leaves the right ventricle by the way of left and right pulmonary artery and travels back to lungs.during contraction of the ventricle ,the tricuspid valve closes to prevent a backflow of blood to the right atrium. ❯ In the lungs ,the pulmonary artery branches into millions of capillaries,each lying close to the alveolus. Here the carbon dioxide in the blood is exchanged for oxygen that has been drawn into lungs during inhalation. ❯ Pulmonary artery unites to form four pulmonary veins- 2 right pulmonary veins and 2 left pulmonary veins.these vessels carry oxygenated blood back to heart. ❯ They deposit blood into left atrium then into left ventricle via bicuspid valve.on contraction of left ventricle , the oxygenated blood leaves the left ventricle through aorta then into different parts of body. Cardiac cycle ❯ The cardiac cycle refers to all the events that occur from the beginning of one heartbeat to the beginning of next heartbeat. ❯ Duration- 0.8 s] ❯ Heartsounds are created from blood flowing through the heart chambers as the cardiac valves open and close during the cardiac cycle ❯ Systole occurs when the heart contracts to pump blood out and diastole occurs when the heart relaxes after contraction Heart sounds ❯ 2 heart sounds: lub and dub ❯ First heart sound: (S1)-closing of av valve ❯ Second heart sound (S2)-clsing of semilunar valve  Conduction system of heart ❯ Electrical signals begins in sinoatrial node(SA Node) located at the top of right atrium ❯ Pacemaker of heart- SA nodeum ❯ When an electrical impulse is released from the SA node transmitted to atrioventricular node(av node) it causes atria to contract.. ❯ From this point to bundle of his relays impulses into purkinje fibres ❯ Purkinje fibres transmit impulses to right and left ventricles causing them to contract. ❯ Blood is now forced from heart through pulmonary artery and aorta. ecg-electrocardiogram ❯ Instrument-electrocaridograph ❯ Procedure-electrocariography ❯ Record obtain-electrocardiogram Vascular system ❯ Arteries-carry blood from heart to parts of body ❯ Veins- returns blood to heart ❯ Capillary-connect artery to vein  pulse ❯ Number of heart beats/min Normal pulse rate-60-100 beats /min ❯ Arrhythmias- abnormal heart beat Bradycardia-