Introduction to the CVS (Cardiovascular System) pptx

Introduction to the CVS (Cardiovascular System) Physiology Lecture. pptx

1. Introduction to Cardiovascular System 1 Lecture by Dr. M. Baqir Raza Naqvi

2. INTRODUCTION The cardiovascular system is transport system of body It comprises blood, heart and blood vessels. The system supplies nutrients to and remove waste products from various tissue of body. The conveying media is liquid in form of blood which flows in close tubular system. Figure 1-2(f) 2

3. FUNCTION OF CARDIOVASCULAR SYSTEM Transport nutrients, hormones. Remove waste products. Gaseous exchange . Immunity. Blood vessels transport blood Carries oxygen and carbon dioxide Also carries nutrients and wastes Heart pumps blood through blood vessels 3

4. COMPONENTS OF CARDIOVASCULAR SYSTEM BLOOD HEART BLOOD VESSELS 4

5. BLOOD The Blood: Blood cells & Plasma Blood cells 1- Erythrocytes - Red Blood Cells 2- Leucocytes 3- Thrombocytes Plasma is fluid portion 5

6. HEART Heart is a four chambered, hollow muscular organ approximately the size of your fist. Location: Superior surface of diaphragm Left of the midline Anterior to the vertebral column, posterior to the sternum , Cardiovascular System 6 6

7. HEART Chapter 18, Cardiovascular System 7 Figure 18.1 7

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9. 12.3 Anatomy 9

10. Path of blood flow through the entire cardiovascular system. All the structures within the colored box are located in the heart. 12.3 Anatomy 10

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12. Electric potential/Action potential/Cardiac muscles contractions 12

13. FUNCTIONS OF THE HEART Generating blood pressure Routing blood Heart separates pulmonary and systemic circulations Ensuring one-way blood flow Heart valves ensure one-way flow Regulating blood supply Changes in contraction rate and force match blood delivery to changing metabolic needs 13

14. ACTIONS OF THE HEART 14 Actions of the heart are classified into five types

15. 1. CHRONOTROPIC ACTION It is of two types i. Tachycardia or increase in heart rate ii. Bradycardia or decrease in heart rate. 15 Chronotropic action is the frequency of heartbeat or heart rate .

16. 2. INOTROPIC ACTION It is of two types i . Positive inotropic action or increase in the force of contraction ii. Negative inotropic action or decrease in the force of contraction. 16 Force of contraction of heart is called inotropic action.

17. 3. DROMOTROPIC ACTION Dromotropic action is the conduction of impulse through heart. 17 It is of two types i . Positive dromotropic action or increase in the velocity of conduction ii. Negative dromotropic action or decrease in the velocity of conduction

18. 4. BATHMOTROPIC ACTION Bathmotropic action is the excitability of cardiac muscle. 18 It is also of two types, i . Positive bathmotropic action or increase in the excitability of cardiac muscle. ii. Negative bathmotropic action or decrease in the excitability of cardiac muscle.

19. 19 Regulation of Actions of Heart All the actions of heart are continuously regulated. It is essential for heart to cope up with the needs of body. All the actions are altered by stimulation of nerves supplying the heart or some hormones or hormonal substances secreted in the body.

20. BLOOD VESSELS Blood Vessels -A closed network of tubes These includes: Arteries Capillaries Veins 20

21. 1- Arteries(Distributing channel) Thick walled tubes Elastic Fibers Circular Smooth Muscle 2 Capillaries (microscopic vessels) One cell thick Serves the Respiratory System 3 Veins (draining channel) 21 BLOOD VESSELS

22. CLASSIFICATION OF BLOOD VESSELS Conducting Vessels Distributing Vessels Resistance Vessels Exchange Vessels Capacitance / Reservoir Vessels 22

23. ARTERIES Blood vessels that carry blood away from the heart are called arteries. They are the thickest blood vessels and they carry blood high in oxygen known as oxygenated blood (oxygen rich blood). Characteristics of Arteries Accompanied by vein and nerves Lumen is small No valves Repeated branching 23 ARTERIAL BLOOD SYSTEM

24. 1. Tunica intima Inner area, which is made up of endothelium . It is the continuation of endocardium. 2. Tunica media Middle area, which is formed by smooth muscles. 3. Tunica adventitia Outer tunica adventitia, which is made up of connective tissue layer. It is the continuation of fibrous layer of parietal pericardium. 24 ARTERIAL BLOOD SYSTEM Arterial system comprises the aorta, arteries and arterioles . Walls of the aorta and arteries are formed by three layers;

25. 25 ARTERIAL BLOOD SYSTEM Diameter/Size of Arteries Arterial branches become narrower and their walls become thinner while reaching the periphery. Aorta has got the maximum diameter of about 25 mm. Diameter of the arteries is gradually decreased and at the end arteries, it is about 4 mm. It further decreases to 30 µ in the arterioles and ends up with 10 µ in the terminal arterioles.

26. CLASSIFICATION OF ARTEIES Elastic- e.g. (Aorta & its Major branches) Muscular - e.g.(Renal, Testicular, Radial, Tibial etc.) Arterioles (<0.1 mm)- Terminal arterioles Meta-arterioles Thoroughfare channel/ preferred 26

27. CAPILLARIES (5-8 micron) The smallest blood vessels are capillaries and they connect the arteries and veins. This is where the exchange of nutrients and gases occurs. 27

28. 28 Diameter of capillaries Arterioles are continued as capillaries, which are small, thin walled vessels having diameter of 5 - 8 µ. Types of capillaries Body contains two kinds of capillaries Continuous - (skin, lung, smooth muscle, connective tissues) Fenestrated- ( pancreas, endocrine glands, small intestine, choroid plexus, cilliary process etc.) Functions of Capillaries Capillaries are functionally very important because, the exchange of materials between the blood and the tissues occurs through these vessels.

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30. SINUSOIDS Large irregular vascular space (30-40 micron) e.g. Liver, Spleen, Bone marrow, suprarenal, Parathyroid etc. 30

31. VEINS Blood vessels that carry blood back to the heart are called veins. They carry blood that is high in carbon dioxide known as deoxygenated blood (oxygen poor blood). 31

32. CHARACTERISTICS OF VEINS Thin Walled Large irregular lumen Have valves Dead space around Types Large Medium Small 32 They have one-way valves which prevent blood from flowing backwards.

33. VEINS Veins without valves SVC & IVC Hepatic, Renal Uterine, Ovarian not Testicular Facial Pulmonary Umbilical Portal Veins <2mm 33

34. VEINS Veins without Muscular tissue: Dural venous sinuses Pial Veins Retinal Veins of erectile tissue of sex organs Veins of spongy bones 34

35. VEINS Factors responsible for venous return Muscle contraction Negative intrathoracic pressure Pulsation of arteries Gravity Valves 35

36. From the capillaries, venous system starts and it includes venules, veins and venae cavae. Capillaries end in venules, which are the smaller vessels with thin muscular wall than the arterioles. Diameter of the venules is about 20 µ . At a time, a large quantity of blood is held in venules and hence the venules are called capacitance vessels. Venules are continued as veins, which have the diameter of 5 mm. Veins form superior and inferior venae cavae, which have a diameter of about 30 mm . 36 DIAMETER OF VEINS

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38. COMPLICATIONS IN BLOOD VESSELS 1. Aorta and Arteries Arterial blood vessels are highly susceptible for arteriosclerosis and atherosclerosis. Arteriosclerosis is the disease of the arteries, associated with hardening, thickening and loss of elasticity in the wall of the vessels. Atherosclerosis is the disease marked by the narrowing of lumen of arterial vessel due to deposition of cholesterol. 38

39. 39 COMPLICATIONS IN BLOOD VESSELS

40. 2. Arterioles When the tone of the smooth muscles in the arterioles increases, hypertension occurs. 3. Capillaries Permeability of the capillary membrane may increase resulting in shock or edema due to leakage of fluid, proteins and other substances from blood. 40 COMPLICATIONS IN BLOOD VESSELS

41. 4. Veins Inflammation of the wall of veins leads to the formation of intravascular clot called thrombosis. The clot gets dislodged, as thrombus. The thrombus travels through blood and causes embolism. Embolism obstructs the blood flow to vital organs such as brain, heart and lungs, leading to many complications. 41 COMPLICATIONS IN BLOOD VESSELS

42. 42 Pulmonary Embolism Deep vein thrombosis

43. CIRCULATION Coronary circulation – the circulation of blood within the heart . Pulmonary circulation – the flow of blood between the heart and lungs. Systemic circulation – the flow of blood between the heart and the cells of the body. Fetal Circulation 43

44. SYSTEMIC AND PULMONARY CIRCULATION Pulmonary circulation The flow of blood between the heart and lungs. Systemic circulation T he flow of blood between the heart and the cells of the body. 44 44

45. Chapter 18, Cardiovascular System 45 CORONARY CIRCULATION: ARTERIAL SUPPLY Figure 18.7a 45

46. PORTAL CIRCULATION Portal circulation - the flow of blood between tow set of capillaries before draining in systemic veins. 46

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48. FETAL CIRCULATION 48

49. 49 FETAL CIRCULATION

50. UMBILICAL ARTERY DESCENDING AORTA (Through Ductus Arteriosus) PULMONARY TRUNK RIGHT VENTRICLE ASCENDING AORTA UMBILICAL VEIN PORTAL VEIN (Through Ductus Venosus) INFERIOR VENA CAVA RIFHT ATRIUM (Through Foramen Ovale) LEFT ATRIUM PLACENTA 50 FETAL CIRCULATION

51. APPLIED PHYSIOLOGY Diseases and Disorders Blood Pressure Hemorrhage/Stroke Arteriosclerosis Aneurysm Coronary Artery Disease (CAD) Heart Attack Congestive Heart Failure (CHF) Anemia, Hemophilia, And Leukemia 51

52. APPLIED Problems with the cardiovascular system are common, but they don’t just affect older people. Many heart problems affect children and teenagers. 52

53. 53 PRACTICE QUESTIONS

54. QUESTIONS 1-All of the following are the example of elastic arteries except: Aorta Common carotid artery Subclavian artery Radial artery 54

55. QUESTIONS 2-All of the following are the example of end arteries except: Central branches of cerebral arteries Central artery of retina Facial artery Splenic artery 55

56. QUESTIONS 3-Arteriovenous anastomosis are found at all of the following sites except: Skin of lips Erectile tissue of penis Thyroid gland Liver 56

57. QUESTIONS 4-All of the following are the example of portal circulation except: Hepatic circulation Renal circulation Circulation of hypophysis cerebri Pulmonary circulation 57

58. QUESTIONS 5-All of the following are features of veins except: Thin walls Thin tunica media Thin tunica adventia Wide lumen 58