1. 1. Compiled By: Prof. G B Rathod ET department-BVM College, Email: ghansyam.rathod@bvmengineering.ac.in THE CARDIOVASCULAR SYSTEM
2. 2. TOPIC OUTLINES THE HEART AND CONDUCTION SYSTEM THE HEART BLOOD PRESSURE CHARACTERISTICS OF BLOOD FLOW HEART SOUND TOPIC OUTCOME QUESTIONS REFERENCES 8/5/20152 BVM ET, BMI(171006)
3. 3. THE HEART AND CARDIOVASCULAR SYSTEM 8/5/2015BVM ET, BMI(171006)3 Two side of the heart with four chambers where the circulatory path for blood flow through the lungs is called the pulmonary circulation , and the circulatory system that supplies oxygen and nutrients to the cells of the body is called the systemic circulation. The left heart is know as a pressure pump and right part of the heart is known as a volume pump. The muscle contraction of the left heart is stronger than that of the right heart. The muscles of the heart receives their own blood supply form the coronary arteries.
4. 4. THE HEART AND CARDIOVASCULAR SYSTEM 8/5/2015BVM ET, BMI(171006)4 The coronary arterial system is a special branch of the systemic circulation. The pipes, the arteries and the veins, are not rigid but flexible. They are capable of helping and controlling blood circulation by their own muscular action and their own valve and receptor system. The actual physiological system for the heart and circulation is illustrated in the upcoming diagram and also equivalent engineering type of piping diagram is shown.
5. 5. THE HEART AND CARDIOVASCULAR SYSTEM 8/5/2015BVM ET, BMI(171006)5
6. 6. THE HEART AND CARDIOVASCULAR SYSTEM 8/5/2015BVM ET, BMI(171006)6
7. 7. THE HEART AND CARDIOVASCULAR SYSTEM 8/5/2015BVM ET, BMI(171006)7 The heart pumping into two major parts: systol and diastol. Systole is defined as the period of contraction of the heart muscles, specifically the ventricular muscle, at which time blood is pumped into the pulmonary artery and the aorta. Diastole is the period of dilation of the heart cavities as they fill with blood. Normal heart beat rate about 75 beats per minute. The range is around 60 to 85 normal. When person stand up it is higher and when a
8. 8. THE HEART AND CARDIOVASCULAR SYSTEM 8/5/2015BVM ET, BMI(171006)8 In women, its generally higher. In infant is around 140 beat/min The heart pumps about 5 lit/min. Its change in different situation. At any given time, about 75 to 80 percent of the blood is in the veins, about 20 percent in the arteries, and remainder in capillaries.
9. 9. THE HEART 8/5/2015BVM ET, BMI(171006)9 The heart is located between the lungs behind the sternum and above the diaphragm. It is surrounded by the pericardium. Its size is about that of a fist, and its weight is about 250-300 g. Its center is located about 1.5 cm to the left of the midsagittal plane.
10. 10. THE HEART 8/5/2015BVM ET, BMI(171006)10
11. 11. THE HEART 8/5/2015BVM ET, BMI(171006)11 The walls of the heart are composed of cardiac muscle, called myocardium. It consists of four compartments: the right and left atria and ventricles
12. 12. THE HEART 8/5/2015BVM ET, BMI(171006)12 The tricuspid valve regulates blood flow between the right atrium and right ventricle. The pulmonary valve controls blood flow from the right ventricle into the pulmonary arteries The mitral valve lets oxygen- rich blood from your lungs pass from the left atrium into the left ventricle. The aortic valve lets oxygen- rich blood pass from the left ventricle into the aorta, then to the body
13. 13. THE HEART 8/5/2015BVM ET, BMI(171006)13 Electrical signal begins in the sinoatrial (SA) node: "natural pacemaker." causes the atria to contract. The signal then passes through the atrioventricular (AV) node. sends the signal to the ventricles via the bundle of His causes the ventricles to contract.
14. 14. THE HEART 8/5/2015BVM ET, BMI(171006)14
15. 15. THE HEART 8/5/2015BVM ET, BMI(171006)15 The sinoatrial node in humans is in the shape of a crescent and is about 15 mm long and 5 mm wide. The SA nodal cells are self-excitatory, pacemaker cells. They generate an action potential at the rate of about 70 per minute. From the sinus node, activation propagates throughout the atria, but cannot propagate directly across the boundary between atria and ventricles.
16. 16. THE HEART 8/5/2015BVM ET, BMI(171006)16 The atrioventricular node (AV node) is located at the boundary between the atria and ventricles; it has an intrinsic frequency of about 50 pulses/min. If the AV node is triggered with a higher pulse frequency, it follows this higher frequency. In a normal heart, the AV node provides the only conducting path from the atria to the ventricles. Propagation from the AV node to the ventricles is provided by a specialized conduction system.
17. 17. THE HEART 8/5/2015BVM ET, BMI(171006)17 Proximally, this system is composed of a common bundle, called the bundle of His (after German physician Wilhelm His, Jr., 1863-1934). More distally, it separates into two bundle branches propagating along each side of the septum, constituting the right and left bundle branches. (The left bundle subsequently divides into an anterior and posterior branch.) Even more distally the bundles ramify into Purkinje fibers (named after Jan Evangelista Purkinje (Czech; 1787-1869)) that diverge to the inner sides of the ventricular walls.
18. 18. THE HEART 8/5/2015BVM ET, BMI(171006)18 Propagation along the conduction system takes place at a relatively high speed once it is within the ventricular region, but prior to this (through the AV node) the velocity is extremely slow. From the inner side of the ventricular wall, the many activation sites cause the formation of a wavefrom, which propagates through the ventricular mass toward the outer wall. This process results from cell-to-cell activation. After each ventricular muscle region has depolarized, repolarization occurs
19. 19. THE HEART 8/5/2015BVM ET, BMI(171006)19
20. 20. THE HEART 8/5/2015BVM ET, BMI(171006)20 The blood pressure is also affected by the working of heart. Upcoming diagram shows a physiological system as a pump model. In diagram Valve represents the resistance in the various organs. The pressure transducers sense the pressure continuously. On the basis of opening and closing of the valve the pressure is to be determined and control.
21. 21. THE HEART 8/5/2015BVM ET, BMI(171006)21
22. 22. BLOOD PRESSURE 8/5/2015BVM ET, BMI(171006)22 The blood pressure for the human is divided in two parts. Systolic and the Diastolic, Systolic is a pressure when the systole cycle of the heart is running. It means when the ventricular section contracts at that time the blood pressure of arteries is known as the systolic blood pressure. Which is higher value compare to diastolic. Normal is 120 mmHg Diastolic is a pressure while heart is in the second cycle call diastole at which the blood is poured in the atrium section.
23. 23. BLOOD PRESSURE 8/5/2015BVM ET, BMI(171006)23 The diastolic normal value is around 80 mmHg. The value of blood pressure at the different condition of the body is different. E.g. , while eating, exercise, sleeping, angry The body having its own monitoring system by which it can control the flow of the blood in the special section of mind. More blood pressure can damage the arteries and also can directly affect the heart. Majority heart attacks are due to high blood pressure. We will see the graphical representation of the blood pressure.
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25. 25. BLOOD PRESSURE 8/5/2015BVM ET, BMI(171006)25 Normally the arteries handle the higher value of blood pressure, so it requires a wall of the arteries thick and compare to that the veins are not handling that much of large values, so it requires a thin walls. The diameter of the veins is lager compare to the diameter of the arteries and capillaries. Since about 75 to 80 percent of the blood volume is contained in the venous system, the veins tend to serve as a reservoir for the bodys blood supply. We will see the diagrams of major arteries of the body and veins of the human body.
26. 26. BLOOD PRESSURE 8/5/2015BVM ET, BMI(171006)26
27. 27. BLOOD PRESSURE 8/5/2015BVM ET, BMI(171006)27
28. 28. CHARACTERISTICS OF BLOOD FLOW 8/5/2015BVM ET, BMI(171006)28 The blood flow at any point in the circulatory system is the volume of blood that passes that point during a unit of time. Measured in mmltr/min or ltr/min The blood flow is highest in the pulmonary artery and the aorta, where these blood vessels leaves the heart. The flow at this point is known as the cardiac output, which is in the range of 3.5 to 5 lit/min Blood flow is a function of the blood pressure and flow resistance of the blood vessels in the same way electrical current flow depends on voltage and resistance.
29. 29. CHARACTERISTICS OF BLOOD FLOW 8/5/2015BVM ET, BMI(171006)29 When under the low temperatures or under the influence of certain drugs(e.g., nicotine), the body reduces the blood flow through the skin by vasoconstriction (narrowing) of the capillaries. Heat, excitement, or local inflammation, among other things, can cause vasodilation (widening) of the capillaries, which increase the blood flow, at least locally. The velocity of blood flowing through a vessel is not constant throughout the cross section of the vessel but is a function of the distance from the wall structures.
30. 30. CHARACTERISTICS OF BLOOD FLOW 8/5/2015BVM ET, BMI(171006)30
31. 31. CHARACTERISTICS OF BLOOD FLOW 8/5/2015BVM ET, BMI(171006)31 When the blood flow in a certain vessel is completely obstructed(e.g., by a blood clot or thrombus), the tissue in the area supplies by this vessel may die. Such obstruction in brain is cause cerebrovascular accident(CVA) or stroke. The coronary arteries that supply blood for the heart muscle is called myocardial (or coronary) infract or heart attack, whereas merely a reduced flow in the coronary vessels can cause a severe chest pain called angina pectoris. The blood clot in a vessel in the lung is called an embolism.
32. 32. HEART SOUNDS 8/5/2015BVM ET, BMI(171006)32 Medical professionals can diagnosis certain types of heart disorders by the sounds and vibrations associated with the beating of the heart and the pumping of blood. The techniques of listening to sounds produced by the organs and vessels of the body is called auscultation. The heart sounds heard by the stethoscope actually occur at the time closure of major valves in the heart. With each heartbeat, the normal heart produces two distinct sounds that are audible in the stethoscope called lub-dub.
33. 33. HEART SOUNDS 8/5/2015BVM ET, BMI(171006)33 The lub is caused by the closure of the atrioventicular valves, which permit flow of blood from the atria into the ventricles but prevent flow in the reverse direction. Normally this is called the first heart sound, its occurs approximately at the time of the QRS complex of the electrocardiogram and just before ventricular systole. The dub part of the heart sounds is called the second heart sound and caused by the closing of the semilunar valves, which release blood into the pulmonary and systemic circulation systems.
34. 34. HEART SOUNDS 8/5/2015BVM ET, BMI(171006)34 The third heart sound is sometimes heard, especially in adults. This sound, which occurs from 0.1 to 0.2 sec after the second heart sound, is attributed to the rush of blood from the atria into the ventricles, which causes turbulence and some vibration of the ventricular walls. An atrial heart sound, which is not audible but may be visible on graphic recording, occurs when the atria actually do contract, squeezing the remainder of the blood into the ventricles. Upcoming figure shows the all heart sounds.
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36. 36. HEART SOUNDS 8/5/2015BVM ET, BMI(171006)36 In abnormal hearts additional sounds, called murmurs, are heard between the normal heart sounds. Murmurs are generally caused either by improper opening of valves or by regurgitation, when the valves do not close completely and allow some backward flow of blood. Another cause of murmurs can be a small opening in the septum, which separates the left and right sides of the heart. The upcoming diagram shows the various types of murmurs.
37. 37. HEART SOUNDS 8/5/2015BVM ET, BMI(171006)37
38. 38. HEART SOUNDS 8/5/2015BVM ET, BMI(171006)38 The first heart sound primarily of energy in the 30 to 45 Hz range. The second heart sound usually higher in pitch than the first with maximum energy in the 50 to 70 Hz range. The third heart sound is and extremely weak vibration, with most of its energy at or below 30 Hz. Murmurs are in the range of 100 to 600 Hz. A graphic recording of heart sounds known as phonocardiogram. The vibrations of the side of the heart as its thumps against hitting the chest wall form the vibrocardiogram.
39. 39. HEART SOUNDS 8/5/2015BVM ET, BMI(171006)39 When an artery is partially occluded so that the blood velocity through the constriction is increased sufficiently, identifiable sounds can be heard downstream through stethoscope. These sounds, called korotkoff sounds, are used in the common method of blood pressure measurements. Ballistocardiogram, is direct result of the dynamic forces of the heart as it beats and pumps blood into the major arteries.
40. 40. OUTCOMES 8/5/2015BVM ET, BMI(171006)40 We come to know about the blood circulation system of the body, heart anatomy, related to that the blood pressure, heart sound and its brief introduction. We also come to know various aspects related to heart and its functioning. Overall we can say the overview of the cardiovascular system that we can relate with the electronics engineering and instrumentation side.
41. 41. REFERENCES 8/5/2015BVM ET, BMI(171006)41 Book: Biomedical instrumentation and measurements ,by L. Cromwell, F .Weibell, and E. Pfeiffer. PHI publication 2nd Edition www.worldofteaching.com
42. 42. QUESTIONS????? 8/5/2015BVM ET, BMI(171006)42 THANK YOU