Cardiovascular system for nursing 1.pptx

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1. Muhammad Ziad lecturer INS-KMU PeshAwar ANATOMY & PHYSIOLOGY CARDIOVASCULAR SYSTEM

2. Objectives At the end of this session, the learner will be able to: Define blood and list its functions Describe the composition, sites of production and functions of cellular parts of blood and plasma Relate & explain the ABO blood groups & Rh factor. Describe the location, structure and functions of the heart and its great blood vessels. Discuss the blood flow through the heart Describe the structure and functional features of the conducting system of the heart.

3. Objectives Describe the principal events of a cardiac cycle. Explain the structure and function of: Arteries Veins & Capillaries Describe the following types of blood circulation: Pulmonary circulation Systemic circulation (coronary & hepatic portal circulation).

4. Blood The fluid connective tissue that circulates in the heart, arteries, capillaries, and veins of a vertebrate animal carrying nourishment and oxygen to and bringing away waste products from all parts of the body. Makes up about 8% of body weight (about 5.6 liters in 70kg man) This proportion is less in women and considerably greater in children, gradually decreasing until the adult level is reached Blood in the blood vessels is always in motion because of pumping action of the heart

5. Blood Composed of clear, straw colored, watery fluid called plasma in which several different types of blood cell are suspended Plasma constitutes 55% of blood volume Remaining 45% is accounted for cellular fraction of blood Plasma and blood cells can be separated by gravity, because cell are heavier than plasma

6. Plasma- 55% Formed elements- 45% Blood Buffy coat- <1%

7. Blood Functions Transportation : It transports oxygen from the lungs to the tissues, and carbon dioxide from the tissue to the lungs for excretion. It transports Nutrients from alimentary tract to the tissue and cell wastes to the excretory organs principally the kidneys. It transports Hormone secreted by endocrine glands to their targeted glands and tissues.

8. Blood Functions It transport heat produced in active tissue to other less active tissue. It transport protective substances e.g antibodies to the area of infection. It transport Clotting factors that coagulate blood, minimizing bleeding from ruptured blood vessels.

9. Blood Functions Regulation: circulating blood helps maintains homeostasis of all body fluids Blood also regulate PH through the use of buffer It also adjust body temperature ( flow through the skin, where excessive heat can be loss from the blood to the environment.

10. Blood Functions Protection: Stop bleeding Defense mechanism Immunity Phagocytosis

11. Physical Characteristics of Blood Thicker than water 7-8 % of total body weight Blood volume 70 mL/kg of body weight 5 - 6 liters in males 4 - 5 liters in females Temperature - 100.4 F pH - 7.35 to 7.45

12. Plasma Constituents of plasma are water (90-92%), and dissolving and suspended substances including Plasma proteins (7%) Inorganic salts Nutrients, principally from digested food Waste materials Hormones Gases

13. Plasma proteins Make up 7% of plasma Responsible for osmotic pressure (applied pressure to stop osmosis) to keep blood within circulation Plasma viscosity is due to plasma protein mainly fibrinogen and albumin Albumin: (54%) formed in liver, main function is to maintain osmotic pressure Albumin also acts as carrier molecule for lipids and steroid hormones

14. Plasma proteins Globulins: (38%) main functions as antibodies (immunoglobulin) produced by lymphocytes Transportation of some hormones and mineral salts e.g. thyroglobin carries the hormone thyroxine and transferrin carries mineral iron Inhibition of some proteolytic enzymes e.g. alpha macroglobulin inhibit trypsin activity Clotting factors: Fibrinogen(7%) is synthesis in liver and essential for blood coagulation

15. Plasma Electrolytes: range of function Muscle contraction e.g. Calcium's Transmission of nerve impulses (potassium and sodium) Maintenance of acid base balance (phosphate) Nutrients The product of digestion e.g. glucose, amino acids, fatty acid and glycerol are absorbed from alimentary tract

16. Plasma Waste product: Urea, creatanine and uric acid are the waste products of protein metabolism formed in liver and carried in blood to kidney for excretion Hormones: chemical messengers synthesized by endocrine glands Gases : Oxygen, carbon dioxide and nitrogen are transported round the body dissolved in blood

17. Cellular content of blood Erythrocytes (Red Cells) 45% of blood Hemoglobin Leukocytes (White Cells ) Granulocytes Neutrophils , eosinophils , and basophils Agranulocytes Monocytes and lymphocytes ( T and B lymphocytes) Platelets (Thrombocytes)

18. Erythrocytes

19. Red Blood Cells RBCs are biconcave Anucleated 7 micrometer in diameter Life span 120 days, then destroyed in spleen (graveyard of RBCs) Hemoglobin- quaternary structure, 2  chains and 2  chains. A  normal RBC count  would be: men – 4.7 to 6.1 million cells per microlitre (cells/ mcL ) women – 4.2 to 5.4 million cells/ mcL 1 RBC contains 280 million hemoglobin molecules

20. Red Blood Cells Function- Transport respiratory gases, mainly of oxygen but also carry some carbon dioxide Their biconcavity increase their surface area for gas exchange and the thinness of central portion allow fast entry and exit of gases The cells are flexible, so they can squeeze through narrow capillaries and contain no intracellular organelles and leave more space for hemoglobin

21. Hematocrit The percentage of total blood volume occupied by RBC’s. - Female: 38%-46% - male: 40%-54% 100%

22. Hemoglobin It is large complex protein containing a globular protien ( globin ) and a pigmented iron containing complex called ( Haem ) Binds strongly, but reversibly, to oxygen Each hemoglobin molecule contain four globin chains and four haem chains, each with one atom of iron: mean each hemoglobin molecule can carry up to four molecules of oxygen An average red blood cell carries about 280 million hemoglobin molecules. Normal hemoglobin in males: 13-18 g/dl & in female: 11.5-16.5 g/dl.

23. Hemoglobin

24. Leukocytes (White Blood Cells) Largest blood cell and Count only 1 % of blood volume Complete cells, with a nucleus and organelles Life span of WBC’s is 13 to 20 days. Function: important in defense and immunity Able to move into and out of blood vessels ( diapedesis ) Can move by ameboid motion Can respond to chemicals released by damaged tissues

25. Types of leukocytes Mainly two types Granulocytes ( Polymorphonuclear leukocytes) Neutrophils , Eosinophils and Basophils Agranulocytes Lack visible cytoplasmic granules Monocytes and lymphocytes

26. Granulocytes Neutrophils (60-70%) Multilobed nucleus with fine granules Act as phagocytes at active sites of infection Eosinophils (2-4%) Large brick-red cytoplasmic granules Found in response to allergies and parasitic worms Basophils (0.5-1.0%) Have histamine-containing granules Initiate inflammation

27. Agranulocytes Lymphocytes (20-25%) Large Nuclei, smaller than monocytes Play an important role in the immune response Monocytes (3-8%) Largest of the white blood cells Function as macrophages Important in fighting chronic infection

28. Significance of High and Low WBC WBC Type Neutrophils Lymphocytes High Count Bacterial infection, burns, stress, inflammation Viral infection, leukemias Radiation exposure, drug toxicity, Vit B12 deficiency, SLE Immuno- suppression, Cortisol use Low Count

29. Significance of High and Low WBC WBC Type Monocytes Eosinophils Basophils High Count Viral or fungal infection, TB, leukemia, chronic disease Allergic reaction, Parasitic infection, autoimmune disease Allergic reaction, cancer, hypothyroidism Bone marrow suppression, cortisol use Drug toxicity, stress Pregnancy, ovulation, hyperthyroidism Low Count

30. Function of WBCs Scavenging:  At the site of injury or infection, neutrophils  in blood and  monocytes  in the tissue engulf worn out cells of the body and dead microbes and thus act as scavengers. Diapedesis :   Neutrophils show  amoeboid movement.   They migrate towards the site of infection, squeeze through capillary walls to engulf and kill microbes.

31. Function of WBCs Phagocytosis:  On reaching site of infection, neutrophils and monocytes engulf microbes or foreign matter or the damaged cells. This is called  phagocytosis.  By phagocytosis, neutrophils kill microorganisms and protect the body against infections. Inflammation or Inflammatory Reaction:  Inflammation is swelling caused at the site of injury. The blood vessels at this point release more blood making it red and hot. Due to accumulation of tissue fluid, the area swells up. The neutrophils and macrophages migrate through capillary wall by diapedesis and fight against invading microbes.

32. Function of WBCs Formation of Antibodies:  Lymphocytes produce antibodies to kill germs and neutralize their toxins(poisons produced by bacteria). Confer Immunity:  Lymphocytes also produce antibodies to provide life long immunity against certain diseases.

33. Platelets (thrombocytes) Small non nucleated disc 2-4 micrometers in diameters Life span 8-11 days Function: promote blood clotting fall in platelets count, kidneys release a substance called thrombopoieten which stimulate platelets synthesis

34. Blood Cell Production

35. Slide 10.5b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

36. Blood group Individuals have different types of antigen (agglutinogen) on the surface of their RBCs These antigens are inherited, determine the individual blood group Individual make antibodies to these antigens but not to their own type of antigen, since if they did the antigen, antibodies would react causing a transfusion reaction which can be fatal

37. ABO BLOOD GROUP History Landsteiners discovered the ABO Blood Group System in 1901 He and five co-workers began mixing each others red blood cells and serum together and accidentally performed the first forward and reverse ABO groupings. About 55% of population have blood group A, blood group B and blood group AB and remaining 45% have blood group O

38. ABO BLOOD GROUP Blood groups are A,B,AB and O Person with Group A having Antigen A makes anti body B Person with Group B having Antigen B makes anti body A Person with Group AB having Antigen A and B and no antibody Person with Group O neither A nor B antigen makes antibodies A and B

39. Universal Donor and Recipient Group O have neither A and B antigens on RBCs, may be safely transfused into A, B, AB and O is known as the Universal Donor Blood group AB have neither A, nor B antibodies, transfusion of either A, B , AB and O is likely to be safe is known as Universal recipients

40. Major ABO Blood Group ABO Group Antigen Present Antigen Missing Antibody Present A A B Anti-B B B A Anti-A O None A and B Anti-A&B AB A and B None None

41. The Rhesus system The red blood cell membrane antigen important here is Rhesus ( Rh ) antigen or rhesus factor About 85% of people have this antigen, they are rhesus positive and do not make their anti rhesus antibodies The remaining 15% have no rhesus antigen, they are rhesus negative

42. Rh Dangers During Pregnancy Danger is only when the mother is Rh – and the father is Rh + , and the child inherits the Rh + factor

43. Rh Dangers During Pregnancy The mismatch of an Rh – mother carrying an Rh + baby can cause problems for the unborn child The first pregnancy usually proceeds without problems The immune system is sensitized after the first pregnancy In a second pregnancy, the mother’s immune system produces antibodies to attack the Rh + blood (hemolytic disease of the newborn)

44. Blood Vessels Blood is carried in a closed system of vessels that begins and ends at the heart The three major types of vessels are arteries , capillaries , and veins Arteries carry blood away from the heart Veins carry blood toward the heart Capillaries contact tissue cells and directly serve cellular needs

45. Anatomy Structure of Blood Vessel Walls

46. Generalized Structure of Blood Vessels Arteries and veins are composed of three tunics – tunica adventitia or outer layer of fibrous tissue tunica media , middle layer of smooth muscle and elastic tissue tunica intima or inner lining of squamous epithelium Lumen – central blood-containing space surrounded by tunics

47. Generalized Structure of Blood Vessels Figure 19.1b

48. Tunics Tunica interna (tunica intima ) Endothelial layer that lines the lumen of all vessels Tunica media Smooth muscle and elastic fiber layer, regulated by sympathetic nervous system Controls vasoconstriction/ vasodilation of vessels Tunica externa (tunica adventitia) Collagen fibers that protect and reinforce vessels Larger vessels contain vasa vasorum

49. Arteries Blood vessel that takes blood away from the heart to all parts of the body (tissues, lungs, etc). Most arteries carry oxygenated blood; the two exceptions are the pulmonary and the umbilical arteries, which carry deoxygenated blood to the organs that oxygenate it.

50. Elastic (Conducting) Arteries Thick-walled arteries - near the heart; the aorta and its major branches Large lumen allow low-resistance conduction of blood Contain elastin in all three tunics Withstand and smooth out large blood pressure fluctuations Allow blood to flow fairly continuously through the body

51. Muscular (Distributing) Arteries and Arterioles Muscular arteries – distal to elastic arteries; deliver blood to body organs Have thick tunica media with more smooth muscle and less elastic tissue Active in vasoconstriction Arterioles – smallest arteries; lead to capillary beds Control flow into capillary beds via vasodilation and constriction

52. Veins Veins  are blood vessels that carry blood toward the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart. The walls of veins are thinner than those of arteries The smallest veins are called venules

53. Capillaries Capillaries - the smallest blood vessels The smallest arterioles break up into number of minute vessels called capillaries Walls consist of single layer of endothelial cell sitting on very thin membrane through which water and other small molecule can pass Allow only a single RBC to pass at a time

54. Blood vessels

55. Heart Cone shaped hollow muscular organ It is about 10-14 cm long, 9 cm wide and the size of your fist. Its weight is 250 g in women and is heavier in men (300 g). The heart lies in thoracic cavity in the mediastinum.

56. Heart Anatomy Location Superior surface of diaphragm Left of the midline Anterior to the vertebral column, posterior to the sternum. Base lies at 2 nd intercostal space & apex at 5 th intercostal space. Structure Composed of three layers of tissue pericardium, myocardium and endocardium 63

57. Heart Anatomy 64

58. Heart layers Pericardium – a double-walled sac around the heart composed of: A superficial fibrous pericardium A deep two-layer serous pericardium The parietal layer lines the internal surface of the fibrous pericardium The visceral layer or epicardium lines the surface of the heart They are separated by the fluid-filled pericardial cavity called pericardial fluid: 25-35 ml. 65

59. Coverings of the Heart: Physiology The Function of the Pericardium: Protects and anchors the heart Prevents overfilling of the heart with blood Allows for the heart to work in a relatively friction-free environment

60. Pericardial Layers of the Heart 67

61. Heart layers Myocardium Is composed of specialized cardiac muscle found only in the heart Is involuntary Thickest layer of heart wall. The end branches of cell are close contact with adjacent cell

62. Heart layers Endocardium: This lines the chambers and valves of the heart It is thin, smooth, glistening membrane that permits smooth flow of blood inside the heart It consist of flattened epithelial cells and it is continuous with the endothelium lining the blood vessels

63. Actions of the Heart Actions of the heart are classified into four types: 1. Chronotropic action----Heart Rate 2. Inotropic action.......Force of contraction 3. Dromotropic action.......Conduction of impulse 4. Bathmotropic action.......Excitability of muscles

64. External Heart: Anterior View Chapter 18, Cardiovascular System 71 Figure 18.4b

65. Major Vessels of the Heart Vessels returning blood to the heart include: Right and left pulmonary veins Superior and inferior venae cavae Vessels conveying blood away from the heart include: Aorta Right and left pulmonary arteries 72

66. External Heart: Posterior View 73 Figure 18.4d

67. Gross Anatomy of Heart: Frontal Section 74 Figure 18.4e

68. Cardiac Chambers Human heart has 4 chambers 2 Atria Superior = primary receiving chambers, do not actually pump Blood flows into atria 2 Ventricles Pump blood Contraction = blood sent out of heart + circulated Chambers are separated by septum… Due to separate chambers, heart functions as double pump

69. Atria of the Heart Atria are the receiving chambers of the heart Each atrium has a protruding auricle. Pectinate muscles are found in atria. Blood enters right atria from superior and inferior venae cava and coronary sinus Blood enters left atria from pulmonary veins Chapter 18, Cardiovascular System 78

70. Ventricles of the Heart Ventricles are the discharging chambers of the heart Papillary muscles and trabeculae carneae muscles mark ventricular walls Right ventricle pumps blood into the pulmonary trunk Left ventricle pumps blood into the aorta Chapter 18, Cardiovascular System 79

71. Blood Flow Through Heart Blood flows into the Right Atrium from: Top half of the body via the Superior Vena Cava Bottom half of the body via the Inferior Vena Cava. From the heart via the Opening to the Coronary Sinus. Coronary Sinus is the gathering point for deoxygenated blood gathered by the cardiac veins.

72. Right Atrium In the right atrium you will see ridges of pectinate muscle. Also there is a blind pocket called the right auricle , which is visible on from the anterior surface of the heart. When looking at the interatrial septum , (the wall between the left and right atria), you will see the circular fossa ovalis . The fossa ovalis is the remnant of the foramen ovalis, a hole that allowed for blood flow between the left and right atria during development in the womb.

73. Right Atrium to Right Ventricle Blood passes from the right atrium to right ventricle through a valve called the tricuspid valve . The chordae tendinae attach the tricuspid valve to papillary muscles which causes the tricuspid valve to close to prevent backflow.

74. Right Ventricle The right ventricle’s myocardium is not as thick as the left ventricles. Remember the myocardium that forms a wall between the left and right ventricles is called the interventricular septum. When the right ventricle contracts, blood is sent up through the pulmonary trunk , which splits into the right and left pulmonary arteries , the only arteries with deoxygenated blood in them. Backflow is prevented by the pulmonary semilunar valve.

75. Lungs to Left Side of the Heart Oxygenated blood returns to the left atrium via the left and right pulmonary veins. The valve between the left atrium and left ventricles is called bicuspid valve. When the thick myocardium of the left ventricle contracts it pushes blood up through the ascending aorta.

76. Outflow Blood is prevented from backflow via aortic semilunar valve . The first exits out the aorta are the openings to the coronary arteries , which supply blood to the heart. The ascending aorta curves around to become the aortic arch, which has three major arteries branching off before it becomes the descending aorta. The branches are the brachiocephalic artery, left common carotid artery, and left subclavian artery.

77. CORONARY CIRCULATION Heart is supplied by TWO CORONARY arteries: 1- Right coronary artery---(RCA) 2- Left coronary artery---(LCA) These coronary arteries arise at the root of the aorta.

78. Coronary arteries & their branches Left coronary artery ---- it passes under the left atrium and divides into two branches: 1. Circumflex Artery . It continues around the left side of the heart and supplies blood to the left atrium and posterior wall of the left ventricle. 2. Left Anterior Descending (LAD) It gives off smaller branches to the interventricular septum and anterior walls of both ventricles.

79. Right coronary artery ---- It gives off two branches: Marginal Artery It supplies blood to the lateral aspect of the right atrium and ventricle. 2. Posterior descending artery It supplies blood to the posterior walls of both ventricles.

80. Portal Circulation: The portal vein drains almost all of the blood from the digestive tract and empties directly into the liver. This circulation of nutrient-rich blood between the gut and liver is called the portal circulation . It enables the liver to remove any harmful substances that may have been digested before the blood enters the main blood circulation around the body—the systemic circulation.

81. Cardiac Cycle Cardiac cycle consists of systole and diastole of atria and ventricles Atrial Systole (Atrial contraction): Lasts about 0.1 sec At the same time, the ventricles are relaxed Atrial depolarization causes atrial systole. Blood is forced via AV valves into the ventricles.

82. Cardiac Cycle Atrial systole contributes 25 ml of blood to the volume of 105 ml already in each ventricle. At the end of ventricular diastole, each ventricle has 130 ml. This blood volume (120—130 ml) is called end-diastolic volume (EDV). The percentage of the EDV ejected (about 60%) is ejection fraction .

83. Ventricular Systole: It lasts about 0.3 sec At the same time, the atria are relaxed. Ventricular depolarization causes ventricular systole. The right and left ventricles eject about 70 ml of blood each into the pulmonary trunk and aorta respectively. The blood volume remaining in each ventricle at the end of systole, about 60 ml, is the end-systolic volume (ESV) . Stroke volume (the volume ejected per beat by each ventricle) equals EDV minus ESV (SV=EDV—ESV ).

84. Cardiac Output: The amount of blood ejected by each ventricle in one minute is called cardiac output (CO). Cardiac output = Heart rate × Stroke volume Pre-load: Degree of tension on muscle when it begins to contract Pre-load = end-diastolic pressure After-load: Load against which muscle exerts its contractile force. After-load = pressure in aorta and pulmonary trunk

85. Cardiac Cycle The average time required to complete the cardiac cycle is usually less than one second (about 0.8 seconds at a heart rate of 75 beats/minute). 0.1 seconds – atria contract ( atrial “kick”), ventricles are relaxed 0.3 seconds – atria relax, ventricles contract 0.4 seconds – relaxation period for all chambers, allowing passive filling. When heart rate increases, it’s this relaxation period that decreases the most .

86. Cardiac Cycle Valves AV SL Outflow Ventricular diastole Open Closed Atrial systole Ventricular systole Closed Open Early atrial diastole Ventricular diastole Open Closed Late atrial diastole

87. Heart Sounds The first sound (lubb) occurs as ventricle contract & AV valve are closing. The second sound (Dupp) occurs as ventricle relax & aortic & pulmonary valve are closing.

88. Path of Blood Pulmonary Circuit Blood flow between the lungs and heart Supplied by the Right side of the heart Systemic Circuit Blood flow between the rest of the body and heart Supplied by the Left side of the heart

89. Pulmonary Circulation In series with the systemic circulation. Receives 100% of cardiac output (3.5L/min/m 2 ). RBC travels through lung in 4-5 seconds. 280 billion capillaries, supplying 300 million alveoli. Surface area for gas exchange = 50 – 100 m 2

90. Pulmonary circulation

91. Systemic circulation / greater circulation / peripheral circulation.

92. Conduction system of the heart The heart possesses the property of autorythmicity which mean it generates its own electrical impulses and beats independently of nervous and hormonal control However it is supplied with both sympathetic and parasympathetic nerve fibers which increase and decrease respectively the intrinsic heart rate

93. Conduction system of the heart The heart responds to a number of circulating hormones including adrenaline ( epinephrine) and thyroxine Small groups of specialized neuromuscular cells in the myocardium initiate and conduct the impulses causing coordinated and synchronized contraction of the heart muscle

94. Autorhythmic fibers: The Conduction system An inherent and rhythmical activity is the reason for the heart life long beat The source of this electrical activity is a network of specialized cardiac muscle fibers called autorhythmic fiber because they are self excitable

95. THANKS